CWinApp Class

 

The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.

The latest version of this topic can be found at CWinApp Class.

The base class from which you derive a Windows application object.

Syntax

class CWinApp : public CWinThread  

Members

Public Constructors

Name	Description
CWinApp::CWinApp	Constructs a CWinApp object.

Public Methods

Name	Description
CWinApp::AddDocTemplate	Adds a document template to the application's list of available document templates.
CWinApp::AddToRecentFileList	Adds a filename to the most recently used (MRU) file list.
CWinApp::ApplicationRecoveryCallback	Called by the framework when the application unexpectedly exits.
CWinApp::CloseAllDocuments	Closes all open documents.
CWinApp::CreatePrinterDC	Creates a printer device context.
CWinApp::DelRegTree	Deletes a specified key and all its subkeys.
CWinApp::DoMessageBox	Implements [AfxMessageBox]--brokenlink--(../Topic/not%20found.md#afxmessagebox) for the application.
CWinApp::DoWaitCursor	Turns the wait cursor on and off.
CWinApp::EnableD2DSupport	Enables application D2D support. Call this method before the main window is initialized.
CWinApp::EnableHtmlHelp	Implements HTMLHelp for the application, rather than WinHelp.
CWinApp::EnableTaskbarInteraction	Enables Taskbar interaction.
CWinApp::ExitInstance	Override to clean up when your application terminates.
CWinApp::GetApplicationRecoveryParameter	Retrieves the input parameter for the application recovery method.
CWinApp::GetApplicationRecoveryPingInterval	Returns the length of time that the restart manager waits for the recovery callback function to return.
CWinApp::GetApplicationRestartFlags	Returns the flags for the restart manager.
CWinApp::GetAppRegistryKey	Returns key for HKEY_CURRENT_USER\"Software"\RegistryKey\ProfileName.
CWinApp::GetDataRecoveryHandler	Gets the data recovery handler for this instance of the application.
CWinApp::GetFirstDocTemplatePosition	Retrieves the position of the first document template.
CWinApp::GetHelpMode	Retrieves the type of help used by the application.
CWinApp::GetNextDocTemplate	Retrieves the position of a document template. Can be used recursively.
CWinApp::GetPrinterDeviceDefaults	Retrieves the printer device defaults.
CWinApp::GetProfileBinary	Retrieves binary data from an entry in the application's .INI file.
CWinApp::GetProfileInt	Retrieves an integer from an entry in the application's .INI file.
CWinApp::GetProfileString	Retrieves a string from an entry in the application's .INI file.
CWinApp::GetSectionKey	Returns key for HKEY_CURRENT_USER\"Software"\RegistryKey\AppName\lpszSection.
CWinApp::HideApplication	Hides the application before closing all documents.
CWinApp::HtmlHelp	Calls the HTMLHelp Windows function.
CWinApp::InitInstance	Override to perform Windows instance initialization, such as creating your window objects.
CWinApp::IsTaskbarInteractionEnabled	Tells whether Windows 7 Taskbar interaction is enabled.
CWinApp::LoadCursor	Loads a cursor resource.
CWinApp::LoadIcon	Loads an icon resource.
CWinApp::LoadOEMCursor	Loads a Windows OEM predefined cursor that the OCR_ constants specify in WINDOWS.H.
CWinApp::LoadOEMIcon	Loads a Windows OEM predefined icon that the OIC_ constants specify in WINDOWS.H.
CWinApp::LoadStandardCursor	Loads a Windows predefined cursor that the IDC_ constants specify in WINDOWS.H.
CWinApp::LoadStandardIcon	Loads a Windows predefined icon that the IDI_ constants specify in WINDOWS.H.
CWinApp::OnDDECommand	Called by the framework in response to a dynamic data exchange (DDE) execute command.
CWinApp::OnIdle	Override to perform application-specific idle-time processing.
CWinApp::OpenDocumentFile	Called by the framework to open a document from a file.
CWinApp::ParseCommandLine	Parses individual parameters and flags in the command line.
CWinApp::PreTranslateMessage	Filters messages before they are dispatched to the Windows functions TranslateMessage and DispatchMessage.
CWinApp::ProcessMessageFilter	Intercepts certain messages before they reach the application.
CWinApp::ProcessShellCommand	Handles command-line arguments and flags.
CWinApp::ProcessWndProcException	Intercepts all unhandled exceptions thrown by the application's message and command handlers.
CWinApp::Register	Performs customized registration.
CWinApp::RegisterWithRestartManager	Registers the application with the restart manager.
CWinApp::ReopenPreviousFilesAtRestart	Determines whether the restart manager reopens the files that were open when the application exited unexpectedly.
CWinApp::RestartInstance	Handles an application restart initiated by the restart manager.
CWinApp::RestoreAutosavedFilesAtRestart	Determines whether the restart manager restores the autosaved files when it restarts the application.
CWinApp::Run	Runs the default message loop. Override to customize the message loop.
CWinApp::RunAutomated	Tests the application's command line for the /Automation option. Obsolete. Instead, use the value in CCommandLineInfo::m_bRunAutomated after calling ParseCommandLine.
CWinApp::RunEmbedded	Tests the application's command line for the /Embedding option. Obsolete. Instead, use the value in CCommandLineInfo::m_bRunEmbedded after calling ParseCommandLine.
CWinApp::SaveAllModified	Prompts the user to save all modified documents.
CWinApp::SelectPrinter	Selects a printer previously indicated by a user through a print dialog box.
CWinApp::SetHelpMode	Sets and initializes the type of help used by the application.
CWinApp::SupportsApplicationRecovery	Determines whether the restart manager recovers an application that exited unexpectedly.
CWinApp::SupportsAutosaveAtInterval	Determines whether the restart manager autosaves open documents at a regular interval.
CWinApp::SupportsAutosaveAtRestart	Determines whether the restart manager autosaves any open documents when the application restarts.
CWinApp::SupportsRestartManager	Determines whether the application supports the restart manager.
CWinApp::Unregister	Unregisters everything known to be registered by the CWinApp object.
CWinApp::WinHelp	Calls the WinHelp Windows function.
CWinApp::WriteProfileBinary	Writes binary data to an entry in the application's .INI file.
CWinApp::WriteProfileInt	Writes an integer to an entry in the application's .INI file.
CWinApp::WriteProfileString	Writes a string to an entry in the application's .INI file.

Protected Methods

Name	Description
CWinApp::EnableShellOpen	Allows the user to open data files from the Windows File Manager.
CWinApp::LoadStdProfileSettings	Loads standard .INI file settings and enables the MRU file list feature.
CWinApp::OnContextHelp	Handles SHIFT+F1 Help within the application.
CWinApp::OnFileNew	Implements the ID_FILE_NEW command.
CWinApp::OnFileOpen	Implements the ID_FILE_OPEN command.
CWinApp::OnFilePrintSetup	Implements the ID_FILE_PRINT_SETUP command.
CWinApp::OnHelp	Handles F1 Help within the application (using the current context).
CWinApp::OnHelpFinder	Handles the ID_HELP_FINDER and ID_DEFAULT_HELP commands.
CWinApp::OnHelpIndex	Handles the ID_HELP_INDEX command and provides a default Help topic.
CWinApp::OnHelpUsing	Handles the ID_HELP_USING command.
CWinApp::RegisterShellFileTypes	Registers all the application's document types with the Windows File Manager.
CWinApp::SetAppID	Explicitly sets Application User Model ID for the application. This method should be called before any user interface is presented to user (the best place is the application constructor).
CWinApp::SetRegistryKey	Causes application settings to be stored in the registry instead of .INI files.
CWinApp::UnregisterShellFileTypes	Unregisters all the application's document types with the Windows File Manager.

Public Data Members

Name	Description
CWinApp::m_bHelpMode	Indicates if the user is in Help context mode (typically invoked with SHIFT+F1).
CWinApp::m_eHelpType	Specifies the type of help used by the application.
CWinApp::m_hInstance	Identifies the current instance of the application.
CWinApp::m_lpCmdLine	Points to a null-terminated string that specifies the command line for the application.
CWinApp::m_nCmdShow	Specifies how the window is to be shown initially.
CWinApp::m_pActiveWnd	Pointer to the main window of the container application when an OLE server is in-place active.
CWinApp::m_pszAppID	Application User Model ID.
CWinApp::m_pszAppName	Specifies the name of the application.
CWinApp::m_pszExeName	The module name of the application.
CWinApp::m_pszHelpFilePath	The path to the application's Help file.
CWinApp::m_pszProfileName	The application's .INI filename.
CWinApp::m_pszRegistryKey	Used to determine the full registry key for storing application profile settings.

Protected Data Members

Name	Description
CWinApp::m_dwRestartManagerSupportFlags	Flags that determine how the restart manager behaves.
CWinApp::m_nAutosaveInterval	The length of time in milliseconds between autosaves.
CWinApp::m_pDataRecoveryHandler	Pointer to the data recovery handler for the application.

Remarks

An application object provides member functions for initializing your application (and each instance of it) and for running the application.

Each application that uses the Microsoft Foundation classes can only contain one object derived from CWinApp. This object is constructed when other C++ global objects are constructed and is already available when Windows calls the WinMain function, which is supplied by the Microsoft Foundation Class Library. Declare your derived CWinApp object at the global level.

When you derive an application class from CWinApp, override the InitInstance member function to create your application's main window object.

In addition to the CWinApp member functions, the Microsoft Foundation Class Library provides the following global functions to access your CWinApp object and other global information:

• [AfxGetApp]--brokenlink--(../Topic/not%20found.md#afxgetapp) Obtains a pointer to the CWinApp object.

• [AfxGetInstanceHandle]--brokenlink--(../Topic/not%20found.md#afxgetinstancehandle) Obtains a handle to the current application instance.

• [AfxGetResourceHandle]--brokenlink--(../Topic/not%20found.md#afxgetresourcehandle) Obtains a handle to the application's resources.

• [AfxGetAppName]--brokenlink--(../Topic/not%20found.md#afxgetappname) Obtains a pointer to a string containing the application's name. Alternately, if you have a pointer to the CWinApp object, use m_pszExeName to get the application's name.

See CWinApp: The Application Class for more on the CWinApp class, including an overview of the following:

• CWinApp-derived code written by the Application Wizard.

• CWinApp's role in the execution sequence of your application.

• CWinApp's default member function implementations.

• CWinApp's key overridables.

The m_hPrevInstance data member no longer exists. For information on detecting a previous instance of CWinApp, see the Knowledge Base article "How To Identify a Previous Instance of an Application" (KB106385) at https://support.microsoft.com/default.aspxscid=kb;en-us;106385.

Inheritance Hierarchy

CObject

CCmdTarget

CWinThread

CWinApp

Requirements

Header: afxwin.h

CWinApp::AddDocTemplate

Call this member function to add a document template to the list of available document templates that the application maintains.

void AddDocTemplate(CDocTemplate* pTemplate);

Parameters

pTemplate
A pointer to the CDocTemplate to be added.

Remarks

You should add all document templates to an application before you call RegisterShellFileTypes.

Example

   // The following code is produced by the Application Wizard when you
   // choose the MDI (multiple document interface) option.
    CMultiDocTemplate* pDocTemplate;
    pDocTemplate = new CMultiDocTemplate(IDR_MYTYPE,
        RUNTIME_CLASS(CMyDoc),
        RUNTIME_CLASS(CChildFrame), // custom MDI child frame
        RUNTIME_CLASS(CMyView));
    if (!pDocTemplate)
        return FALSE;
    AddDocTemplate(pDocTemplate);

CWinApp::AddToRecentFileList

Call this member function to add lpszPathName to the MRU file list.

virtual void AddToRecentFileList(LPCTSTR lpszPathName);

Parameters

lpszPathName
The path of the file.

Remarks

You should call the LoadStdProfileSettings member function to load the current MRU file list before you use this member function.

The framework calls this member function when it opens a file or executes the Save As command to save a file with a new name.

Example

   // This adds the pathname c:\temp\test.doc to the top of
   // the most recently used (MRU) list in the File menu.
   AfxGetApp()->AddToRecentFileList(_T("c:\\temp\\test.doc"));

CWinApp::ApplicationRecoveryCallback

Called by the framework when the application unexpectedly exits.

virtual DWORD ApplicationRecoveryCallback(LPVOID lpvParam);

Parameters

[in] lpvParam
Reserved for future use.

Return Value

0 if this method is successful; nonzero if an error occurs.

Remarks

If your application supports the restart manager, the framework calls this function when your application unexpectedly exits.

The default implementation of ApplicationRecoveryCallback uses the CDataRecoveryHandler to save the list of currently open documents to the registry. This method does not autosave any files.

To customize the behavior, override this function in a derived CWinApp Class or pass your own application recovery method as a parameter to CWinApp::RegisterWithRestartManager.

CWinApp::CloseAllDocuments

Call this member function to close all open documents before exiting.

void CloseAllDocuments(BOOL bEndSession);

Parameters

bEndSession
Specifies whether or not the Windows session is being ended. It is TRUE if the session is being ended; otherwise FALSE.

Remarks

Call HideApplication before calling CloseAllDocuments.

CWinApp::CreatePrinterDC

Call this member function to create a printer device context (DC) from the selected printer.

BOOL CreatePrinterDC(CDC& dc);

Parameters

dc
A reference to a printer device context.

Return Value

Nonzero if the printer device context is created successfully; otherwise 0.

Remarks

CreatePrinterDC initializes the device context that you pass in by reference, so you can use it to print.

If the function is successful, when you have finished printing, you must destroy the device context. You can let the destructor of the CDC object do it, or you can do it explicitly by calling CDC::DeleteDC.

CWinApp::CWinApp

Constructs a CWinApp object and passes lpszAppName to be stored as the application name.

CWinApp(LPCTSTR lpszAppName = NULL);

Parameters

lpszAppName
A null-terminated string that contains the application name that Windows uses. If this argument is not supplied or is NULL, CWinApp uses the resource string AFX_IDS_APP_TITLE or the filename of the executable file.

Remarks

You should construct one global object of your CWinApp-derived class. You can have only one CWinApp object in your application. The constructor stores a pointer to the CWinApp object so that WinMain can call the object's member functions to initialize and run the application.

CWinApp::DelRegTree

Deletes a specific registry key and all its subkeys.

LONG DelRegTree(
    HKEY hParentKey,  
    const CString& strKeyName);

 
LONG DelRegTree(
    HKEY hParentKey,
    const CString& strKeyName,
    CAtlTransactionManager* pTM = NULL);

Parameters

hParentKey
Handle to a registry key.

strKeyName
The name of the registry key to be deleted.

pTM
Pointer to CAtlTransactionManager object.

Return Value

If the function succeeds, the return value is ERROR_SUCCESS. If the function fails, the return value is a nonzero error code defined in Winerror.h.

Remarks

Call this function to delete the specified key and its subkeys.

CWinApp::DoMessageBox

The framework calls this member function to implement a message box for the global function [AfxMessageBox]--brokenlink--(../Topic/not%20found.md#afxmessagebox).

virtual int DoMessageBox(
    LPCTSTR lpszPrompt,  
    UINT nType,  
    UINT nIDPrompt);

Parameters

lpszPrompt
Address of text in the message box.

nType
The message box style.

nIDPrompt
An index to a Help context string.

Return Value

Returns the same values as AfxMessageBox.

Remarks

Do not call this member function to open a message box; use AfxMessageBox instead.

Override this member function to customize your application-wide processing of AfxMessageBox calls.

CWinApp::DoWaitCursor

This member function is called by the framework to implement CWaitCursor, CCmdTarget::BeginWaitCursor, CCmdTarget::EndWaitCursor, and CCmdTarget::RestoreWaitCursor.

virtual void DoWaitCursor(int nCode);

Parameters

nCode
If this parameter is 1, a wait cursor appears. If 0, the wait cursor is restored without incrementing the reference count. If –1, the wait cursor ends.

Remarks

The default implements an hourglass cursor. DoWaitCursor maintains a reference count. When positive, the hourglass cursor is displayed.

While you would not normally call DoWaitCursor directly, you could override this member function to change the wait cursor or to do additional processing while the wait cursor is displayed.

For an easier, more streamlined way to implement a wait cursor, use CWaitCursor.

Example

// The following example shows how to display the
// hourglass cursor during some lengthy processing
void CMdiView::OnLButtonDown(UINT nFlags, CPoint point)
{
   UNREFERENCED_PARAMETER(nFlags);
   UNREFERENCED_PARAMETER(point);

   AfxGetApp()->DoWaitCursor(1); // 1->>display the hourglass cursor

   // do some lengthy processing
   Sleep(1000);

   AfxGetApp()->DoWaitCursor(-1); // -1->>remove the hourglass cursor
}

// The next example shows DoWaitCursor with parameter 0. It restores
// the hourglass cursor.
void CMdiView::OnMButtonDown(UINT nFlags, CPoint point)
{
   UNREFERENCED_PARAMETER(nFlags);
   UNREFERENCED_PARAMETER(point);

   AfxGetApp()->DoWaitCursor(1); // display the hourglass cursor

   // do some lengthy processing

   // The message box will normally change the cursor to
   // the standard arrow cursor, and leave the cursor in
   // as the standard arrow cursor when the message box is
   // closed.
   AfxMessageBox (_T("DoWaitCursor Sample"));

   // Call DoWaitCursor with parameter 0 to restore
   // the cursor back to the hourglass cursor.
   AfxGetApp()->DoWaitCursor(0);

   // do some more lengthy processing
   Sleep(1000);

   AfxGetApp()->DoWaitCursor(-1); // remove the hourglass cursor
}

CWinApp::EnableD2DSupport

Visual Studio 2010 SP1 is required.

Enables application D2D support. Call this method before the main window is initialized.

BOOL EnableD2DSupport(
D2D1_FACTORY_TYPE d2dFactoryType = D2D1_FACTORY_TYPE_SINGLE_THREADED,  
DWRITE_FACTORY_TYPE writeFactoryType = DWRITE_FACTORY_TYPE_SHARED);

Parameters

d2dFactoryType
The threading model of the D2D factory and the resources it creates.

writeFactoryType
A value that specifies whether the write factory object will be shared or isolated

Return Value

Returns TRUE if D2D support was enabled, FALSE - otherwise

CWinApp::EnableHtmlHelp

Call this member function from within the constructor of your CWinApp-derived class to use HTMLHelp for your application's help.

void EnableHtmlHelp();

Remarks

CWinApp::EnableShellOpen

Call this function, typically from your InitInstance override, to enable your application's users to open data files when they double-click the files from within the Windows File Manager.

void EnableShellOpen();

Remarks

Call the RegisterShellFileTypes member function in conjunction with this function, or provide a .REG file with your application for manual registration of document types.

Example

   // The following code fragment is from CMyApp::InitInstance.
   // CMyApp is a CWinApp-derived class.

   // enable file manager drag/drop and DDE Execute open
   EnableShellOpen();
   RegisterShellFileTypes();

CWinApp::EnableTaskbarInteraction

Enables Taskbar interaction.

BOOL EnableTaskbarInteraction(BOOL bEnable = TRUE);

Parameters

bEnable
Specifies whether interaction with Windows 7 taskbar should be enabled ( TRUE), or disabled ( FALSE).

Return Value

Returns TRUE if taskbar interaction can be enabled or disabled.

Remarks

This method must be called before creation of main window, otherwise it asserts and returns FALSE.

CWinApp::ExitInstance

Called by the framework from within the Run member function to exit this instance of the application.

virtual int ExitInstance();

Return Value

The application's exit code; 0 indicates no errors, and values greater than 0 indicate an error. This value is used as the return value from WinMain.

Remarks

Do not call this member function from anywhere but within the Run member function.

The default implementation of this function writes framework options to the application's .INI file. Override this function to clean up when your application terminates.

Example

int CMyApp::ExitInstance()
{
  if (m_pMySampleMem)
     delete m_pMySampleMem;
   
   DoCleanup();

   return CWinApp::ExitInstance();
}

CWinApp::GetApplicationRecoveryParameter

Retrieves the input parameter for the application recovery method.

virtual LPVOID GetApplicationRecoveryParameter();

Return Value

The default input parameter for the application recovery method.

Remarks

The default behavior of this function returns NULL.

For more information, see CWinApp::ApplicationRecoveryCallback.

CWinApp::GetApplicationRecoveryPingInterval

Returns the length of time that the restart manager waits for the recovery callback function to return.

virtual DWORD GetApplicationRecoveryPingInterval();

Return Value

The length of time in milliseconds.

Remarks

When an application that is registered with the restart manager exits unexpectedly, the application tries to save open documents and calls the recovery callback function. The default recovery callback function is CWinApp::ApplicationRecoveryCallback.

The length of time that the framework waits for the recovery callback function to return is the ping interval. You can customize the ping interval by overriding CWinApp::GetApplicationRecoveryPingInterval or by providing a custom value to RegisterWithRestartManager.

CWinApp::GetApplicationRestartFlags

Returns the flags for the restart manager.

virtual DWORD GetApplicationRestartFlags();

Return Value

The flags for the restart manager. The default implementation returns 0.

Remarks

The flags for the restart manager have no effect with the default implementation. They are provided for future use.

You set the flags when you register the application with the restart manager by using CWinApp::RegisterWithRestartManager.

The possible values for the restart manager flags are as follows:

• RESTART_NO_CRASH

• RESTART_NO_HANG

• RESTART_NO_PATCH

• RESTART_NO_REBOOT

CWinApp::GetAppRegistryKey

Returns the key for HKEY_CURRENT_USER\"Software"\RegistryKey\ProfileName.

HKEY GetAppRegistryKey(CAtlTransactionManager* pTM = NULL);

Parameters

pTM
Pointer to a CAtlTransactionManager object.

Return Value

Application key if the function succeeds; otherwise NULL.

Remarks

CWinApp::GetDataRecoveryHandler

Gets the data recovery handler for this instance of the application.

virtual CDataRecoveryHandler *GetDataRecoveryHandler();

Return Value

The data recovery handler for this instance of the application.

Remarks

Each application that uses the restart manager must have one instance of the CDataRecoveryHandler Class. This class is responsible for monitoring open documents and autosaving files. The behavior of the CDataRecoveryHandler depends on the configuration of the restart manager. For more information, see CDataRecoveryHandler Class.

This method returns NULL on operating systems earlier than Windows Vista. The restart manager is not supported on operating systems earlier than Windows Vista.

If the application does not currently have a data recovery handler, this method creates one and returns a pointer to it.

CWinApp::GetFirstDocTemplatePosition

Gets the position of the first document template in the application.

POSITION GetFirstDocTemplatePosition() const;  

Return Value

A POSITION value that can be used for iteration or object pointer retrieval; NULL if the list is empty.

Remarks

Use the POSITION value returned in a call to GetNextDocTemplate to get the first CDocTemplate object.

CWinApp::GetHelpMode

Retrieves the type of help used by the application.

AFX_HELP_TYPE GetHelpMode();

Return Value

The help type used by the application. See CWinApp::m_eHelpType for more information.

CWinApp::GetNextDocTemplate

Gets the document template identified by pos, then sets pos to the POSITION value.

CDocTemplate* GetNextDocTemplate(POSITION& pos) const;  

Parameters

pos
A reference to a POSITION value returned by a previous call to GetNextDocTemplate or GetFirstDocTemplatePosition. The value is updated to the next position by this call.

Return Value

A pointer to a CDocTemplate object.

Remarks

You can use GetNextDocTemplate in a forward iteration loop if you establish the initial position with a call to GetFirstDocTemplatePosition.

You must ensure that your POSITION value is valid. If it is invalid, then the Debug version of the Microsoft Foundation Class Library asserts.

If the retrieved document template is the last available, then the new value of pos is set to NULL.

CWinApp::GetPrinterDeviceDefaults

Call this member function to prepare a printer device context for printing.

BOOL GetPrinterDeviceDefaults(struct tagPDA* pPrintDlg);

Parameters

pPrintDlg
A pointer to a PRINTDLG structure.

Return Value

Nonzero if successful; otherwise 0.

Remarks

Retrieves the current printer defaults from the Windows .INI file as necessary, or uses the last printer configuration set by the user in Print Setup.

Example

void CMyApp::SetLandscapeMode()
{
   PRINTDLG pd;
   pd.lStructSize = (DWORD)sizeof(PRINTDLG);
   BOOL bRet = GetPrinterDeviceDefaults(&pd);
   if(bRet)
   {
      // protect memory handle with ::GlobalLock and ::GlobalUnlock
      DEVMODE FAR *pDevMode = (DEVMODE FAR *)::GlobalLock(pd.hDevMode);
      // set orientation to landscape
      pDevMode->dmOrientation = DMORIENT_LANDSCAPE;
      ::GlobalUnlock(pd.hDevMode);
   }
}

CWinApp::GetProfileBinary

Call this member function to retrieve binary data from an entry within a specified section of the application's registry or .INI file.

BOOL GetProfileBinary(
    LPCTSTR lpszSection,  
    LPCTSTR lpszEntry,  
    LPBYTE* ppData,  
    UINT* pBytes);

Parameters

lpszSection
Points to a null-terminated string that specifies the section containing the entry.

lpszEntry
Points to a null-terminated string that contains the entry whose value is to be retrieved.

ppData
Points to a pointer that will receive the address of the data.

pBytes
Points to a UINT that will receive the size of the data (in bytes).

Return Value

Nonzero if successful; otherwise 0.

Remarks

This member function is not case sensitive, so the strings in the lpszSection and lpszEntry parameters may differ in case.

Example

   CWinApp* pApp = AfxGetApp();

   const TCHAR* pszKey = _T("My Section");
   struct complex {
     double re, im;
   } myData = { 1.4142, -0.5 };

   // Write the information to the registry.

   pApp->WriteProfileBinary(pszKey, _T("ComplexData"), (LPBYTE)&myData, 
      sizeof(myData));

   // Read the information from the registry.

   complex* pData;
   UINT n;
   BOOL ret = pApp->GetProfileBinary(pszKey, _T("ComplexData"), (LPBYTE*)&pData, 
      &n);

   ASSERT(ret);
   ASSERT(n == sizeof(complex));
   ASSERT(myData.re == pData->re);
   ASSERT(myData.im == pData->im);
   delete [] pData; // free the buffer

For an additional example, see CWinApp::WriteProfileBinary.

CWinApp::GetProfileInt

Call this member function to retrieve the value of an integer from an entry within a specified section of the application's registry or .INI file.

UINT GetProfileInt(
    LPCTSTR lpszSection,  
    LPCTSTR lpszEntry,  
    int nDefault);

Parameters

lpszSection
Points to a null-terminated string that specifies the section containing the entry.

lpszEntry
Points to a null-terminated string that contains the entry whose value is to be retrieved.

nDefault
Specifies the default value to return if the framework cannot find the entry.

Return Value

The integer value of the string that follows the specified entry if the function is successful. The return value is the value of the nDefault parameter if the function does not find the entry. The return value is 0 if the value that corresponds to the specified entry is not an integer.

This member function supports hexadecimal notation for the value in the .INI file. When you retrieve a signed integer, you should cast the value into an int.

Remarks

This member function is not case sensitive, so the strings in the lpszSection and lpszEntry parameters may differ in case.

Example

   CWinApp* pApp = AfxGetApp();

   const TCHAR* pszKey = _T("My Section"); 
   const TCHAR* pszName = _T("Julian");
   int iAge = 26;

   // Write the information to the registry.

   pApp->WriteProfileString(pszKey, _T("Name"), pszName);
   pApp->WriteProfileInt(pszKey, _T("Age"), iAge);

   // Read the information from the registry.

   CString strName = pApp->GetProfileString(pszKey, _T("Name"));
   int iAge2 = pApp->GetProfileInt(pszKey, _T("Age"), 0);

   ASSERT(strName == pszName);
   ASSERT(iAge2 == iAge);

For an additional example, see CWinApp::WriteProfileInt.

CWinApp::GetProfileString

Call this member function to retrieve the string associated with an entry within the specified section in the application's registry or .INI file.

CString GetProfileString(
    LPCTSTR lpszSection,  
    LPCTSTR lpszEntry,  
    LPCTSTR lpszDefault = NULL);

Parameters

lpszSection
Points to a null-terminated string that specifies the section containing the entry.

lpszEntry
Points to a null-terminated string that contains the entry whose string is to be retrieved. This value must not be NULL.

lpszDefault
Points to the default string value for the given entry if the entry cannot be found in the initialization file.

Return Value

The return value is the string from the application's .INI file or lpszDefault if the string cannot be found. The maximum string length supported by the framework is _MAX_PATH. If lpszDefault is NULL, the return value is an empty string.

Remarks

Example

   CWinApp* pApp = AfxGetApp();

   CString strSection       = _T("My Section");
   CString strStringItem    = _T("My String Item");
   CString strIntItem       = _T("My Int Item");

   pApp->WriteProfileString(strSection, strStringItem, _T("test"));

   CString strValue;
   strValue = pApp->GetProfileString(strSection, strStringItem);
   ASSERT(strValue == _T("test"));

   pApp->WriteProfileInt(strSection, strIntItem, 1234);

   int nValue;
   nValue = pApp->GetProfileInt(strSection, strIntItem, 0);
   ASSERT(nValue == 1234);

For another example, see the example for CWinApp::GetProfileInt.

CWinApp::GetSectionKey

Returns the key for HKEY_CURRENT_USER\"Software"\RegistryKey\AppName\lpszSection.

HKEY GetSectionKey(
LPCTSTR lpszSection,  
CAtlTransactionManager* pTM = NULL);

Parameters

lpszSection
The name of the key to be obtained.

pTM
Pointer to a CAtlTransactionManager object.

Return Value

Section key if the function succeeds; otherwise NULL.

Remarks

CWinApp::HideApplication

Call this member function to hide an application before closing the open documents.

void HideApplication();

CWinApp::HtmlHelp

Call this member function to invoke the HTMLHelp application.

virtual void HtmlHelp(
    DWORD_PTR dwData,  
    UINT nCmd = 0x000F);

Parameters

dwData
Specifies additional data. The value used depends on the value of the nCmd parameter.

nCmd
Specifies the type of help requested. For a list of possible values and how they affect the dwData parameter, see the uCommand parameter described in About the HTMLHelp API Function in the Windows SDK.

Remarks

The framework also calls this function to invoke the HTMLHelp application.

The framework will automatically close the HTMLHelp application when your application terminates.

CWinApp::InitInstance

Windows allows several copies of the same program to run at the same time.

virtual BOOL InitInstance();

Return Value

Nonzero if initialization is successful; otherwise 0.

Remarks

Application initialization is conceptually divided into two sections: one-time application initialization that is done the first time the program runs, and instance initialization that runs each time a copy of the program runs, including the first time. The framework's implementation of WinMain calls this function.

Override InitInstance to initialize each new instance of your application running under Windows. Typically, you override InitInstance to construct your main window object and set the CWinThread::m_pMainWnd data member to point to that window. For more information on overriding this member function, see CWinApp: The Application Class.

Example

// AppWizard implements the InitInstance overridable function 
// according to options you select.  For example, the multiple document
// interface (MDI) option was chosen for the AppWizard code created
// below. You can add other per-instance initializations to the code
// created by AppWizard.

BOOL CMFCListViewApp::InitInstance()
{
   AfxSetAmbientActCtx(FALSE);
   // Remainder of function definition omitted.

   CWinApp::InitInstance();

   // Initialize OLE libraries
   if (!AfxOleInit())
   {
      AfxMessageBox(_T("OleInit failed."));
      return FALSE;
   }

   // Standard initialization
   // If you are not using these features and wish to reduce the size
   // of your final executable, you should remove from the following
   // the specific initialization routines you do not need
   // Change the registry key under which our settings are stored
   // TODO: You should modify this string to be something appropriate
   // such as the name of your company or organization
   SetRegistryKey(_T("Local AppWizard-Generated Applications"));
   LoadStdProfileSettings(4);  // Load standard INI file options (including MRU)
   // Register the application's document templates.  Document templates
   //  serve as the connection between documents, frame windows and views
   CMultiDocTemplate* pDocTemplate;
   pDocTemplate = new CMultiDocTemplate(IDR_MFCListViewTYPE,
      RUNTIME_CLASS(CMFCListViewDoc),
      RUNTIME_CLASS(CChildFrame), // custom MDI child frame
      RUNTIME_CLASS(CMyListView));
   if (!pDocTemplate)
      return FALSE;
   AddDocTemplate(pDocTemplate);

   // create main MDI Frame window
   CMainFrame* pMainFrame = new CMainFrame;
   if (!pMainFrame || !pMainFrame->LoadFrame(IDR_MAINFRAME))
   {
      delete pMainFrame;
      return FALSE;
   }
   m_pMainWnd = pMainFrame;
   // call DragAcceptFiles only if there's a suffix
   //  In an MDI app, this should occur immediately after setting m_pMainWnd


   // Parse command line for standard shell commands, DDE, file open
   CCommandLineInfo cmdInfo;
   ParseCommandLine(cmdInfo);


   // Dispatch commands specified on the command line.  Will return FALSE if
   // app was launched with /RegServer, /Register, /Unregserver or /Unregister.
   if (!ProcessShellCommand(cmdInfo))
      return FALSE;
   // The main window has been initialized, so show and update it
   pMainFrame->ShowWindow(m_nCmdShow);
   pMainFrame->UpdateWindow();

   return TRUE;
}

CWinApp::IsTaskbarInteractionEnabled

Tells whether Windows 7 Taskbar interaction is enabled.

virtual BOOL IsTaskbarInteractionEnabled();

Return Value

Returns TRUE if EnableTaskbarInteraction has been called and the Operating System is Windows 7 or higher.

Remarks

Taskbar interaction means that MDI application displays the content of MDI children in separate tabbed thumbnails that appear when the mouse pointer is over the application taskbar button.

CWinApp::LoadCursor

Loads the cursor resource named by lpszResourceName or specified by nIDResource from the current executable file.

HCURSOR LoadCursor(LPCTSTR lpszResourceName) const;  HCURSOR LoadCursor(UINT nIDResource) const;  ```  
  
### Parameters  
 `lpszResourceName`  
 Points to a null-terminated string that contains the name of the cursor resource. You can use a `CString` for this argument.  
  
 `nIDResource`  
 ID of the cursor resource. For a list of resources, see [LoadCursor](https://msdn.microsoft.com/library/windows/desktop/ms648391) in the [!INCLUDE[winSDK](../Token/winSDK_md.md)].  
  
### Return Value  
 A handle to a cursor if successful; otherwise **NULL**.  
  
### Remarks  
 `LoadCursor` loads the cursor into memory only if it has not been previously loaded; otherwise, it retrieves a handle of the existing resource.  
  
 Use the [LoadStandardCursor](#cwinapp__loadstandardcursor) or [LoadOEMCursor](#cwinapp__loadoemcursor) member function to access the predefined Windows cursors.  
  
### Example  
 [!CODE [NVC_MFCWindowing#44](../CodeSnippet/VS_Snippets_Cpp/NVC_MFCWindowing#44)]  
  
##  <a name="cwinapp__loadicon"></a>  CWinApp::LoadIcon  
 Loads the icon resource named by `lpszResourceName` or specified by `nIDResource` from the executable file.  
  

HICON LoadIcon(LPCTSTR lpszResourceName) const; HICON LoadIcon(UINT nIDResource) const; ```

Parameters

lpszResourceName
Points to a null-terminated string that contains the name of the icon resource. You can also use a CString for this argument.

nIDResource
ID number of the icon resource.

Return Value

A handle to an icon if successful; otherwise NULL.

Remarks

LoadIcon loads the icon only if it has not been previously loaded; otherwise, it retrieves a handle of the existing resource.

You can use the LoadStandardIcon or LoadOEMIcon member function to access the predefined Windows icons.

CWinApp::LoadOEMCursor

Loads the Windows predefined cursor resource specified by nIDCursor.

HCURSOR LoadOEMCursor(UINT nIDCursor) const;  

Parameters

nIDCursor
An OCR_ manifest constant identifier that specifies a predefined Windows cursor. You must have #define OEMRESOURCE before #include <afxwin.h> to gain access to the OCR_ constants in WINDOWS.H.

Return Value

A handle to a cursor if successful; otherwise NULL.

Remarks

Use the LoadOEMCursor or LoadStandardCursor member function to access the predefined Windows cursors.

Example

// In the stdafx.h file, add #define OEMRESOURCE to
// include the windows.h definitions of OCR_ values.
#define OEMRESOURCE
#include <afxwin.h>         // MFC core and standard components
#include <afxext.h>         // MFC extensions

   HCURSOR hCursor;
   // Load the predefined WIndows "size all" cursor.
   hCursor = AfxGetApp()->LoadOEMCursor(OCR_SIZEALL);

CWinApp::LoadOEMIcon

Loads the Windows predefined icon resource specified by nIDIcon.

HICON LoadOEMIcon(UINT nIDIcon) const;  

Parameters

nIDIcon
An OIC_ manifest constant identifier that specifies a predefined Windows icon. You must have #define OEMRESOURCE before #include <afxwin.h> to access the OIC_ constants in WINDOWS.H.

Return Value

A handle to an icon if successful; otherwise NULL.

Remarks

Use the LoadOEMIcon or LoadStandardIcon member function to access the predefined Windows icons.

CWinApp::LoadStandardCursor

Loads the Windows predefined cursor resource that lpszCursorName specifies.

HCURSOR LoadStandardCursor(LPCTSTR lpszCursorName) const;  

Parameters

lpszCursorName
An IDC_ manifest constant identifier that specifies a predefined Windows cursor. These identifiers are defined in WINDOWS.H. The following list shows the possible predefined values and meanings for lpszCursorName:

• IDC_ARROW Standard arrow cursor

• IDC_IBEAM Standard text-insertion cursor

• IDC_WAIT Hourglass cursor used when Windows performs a time-consuming task

• IDC_CROSS Cross-hair cursor for selection

• IDC_UPARROW Arrow that points straight up

• IDC_SIZE Obsolete and unsupported; use IDC_SIZEALL

• IDC_SIZEALL A four-pointed arrow. The cursor to use to resize a window.

• IDC_ICON Obsolete and unsupported. Use IDC_ARROW.

• IDC_SIZENWSE Two-headed arrow with ends at upper left and lower right

• IDC_SIZENESW Two-headed arrow with ends at upper right and lower left

• IDC_SIZEWE Horizontal two-headed arrow

• IDC_SIZENS Vertical two-headed arrow

Return Value

A handle to a cursor if successful; otherwise NULL.

Remarks

Use the LoadStandardCursor or LoadOEMCursor member function to access the predefined Windows cursors.

Example

   HCURSOR hCursor;
  
   // Load the predefined Windows "up arrow" cursor.
   hCursor = AfxGetApp()->LoadStandardCursor(IDC_UPARROW);   

CWinApp::LoadStandardIcon

Loads the Windows predefined icon resource that lpszIconName specifies.

HICON LoadStandardIcon(LPCTSTR lpszIconName) const;  

Parameters

lpszIconName
A manifest constant identifier that specifies a predefined Windows icon. These identifiers are defined in WINDOWS.H. For a list of the possible predefined values and their descriptions, see the lpIconName parameter in LoadIcon in the Windows SDK.

Return Value

A handle to an icon if successful; otherwise NULL.

Remarks

Use the LoadStandardIcon or LoadOEMIcon member function to access the predefined Windows icons.

CWinApp::LoadStdProfileSettings

Call this member function from within the InitInstance member function to enable and load the list of most recently used (MRU) files and last preview state.

void LoadStdProfileSettings(UINT nMaxMRU = _AFX_MRU_COUNT);

Parameters

nMaxMRU
The number of recently used files to track.

Remarks

If nMaxMRU is 0, no MRU list will be maintained.

CWinApp::m_bHelpMode

TRUE if the application is in Help context mode (conventionally invoked with SHIFT + F1); otherwise FALSE.

BOOL m_bHelpMode;  

Remarks

In Help context mode, the cursor becomes a question mark and the user can move it about the screen. Examine this flag if you want to implement special handling when in the Help mode. m_bHelpMode is a public variable of type BOOL.

CWinApp::m_dwRestartManagerSupportFlags

Flags that determine how the restart manager behaves.

DWORD m_dwRestartManagerSupportFlags;  

Remarks

To enable the restart manager, set m_dwRestartManagerSupportFlags to the behavior that you want. The following table shows the flags that are available.

Flag	Description
AFX_RESTART_MANAGER_SUPPORT_RESTART	The application is registered by using CWinApp::RegisterWithRestartManager. The restart manager is responsible for restarting the application if it unexpectedly exits.
- AFX_RESTART_MANAGER_SUPPORT_RECOVERY	The application is registered with the restart manager and the restart manager calls the recovery callback function when it restarts the application. The default recovery callback function is CWinApp::ApplicationRecoveryCallback.
- AFX_RESTART_MANAGER_AUTOSAVE_AT_RESTART	Autosave is enabled and the restart manager autosaves any open documents when the application restarts.
- AFX_RESTART_MANAGER_AUTOSAVE_AT_INTERVAL	Autosave is enabled and the restart manager autosaves any open documents at a regular interval. The interval is defined by CWinApp::m_nAutosaveInterval.
- AFX_RESTART_MANAGER_REOPEN_PREVIOUS_FILES	The restart manager opens previously open documents after restarting the application from an unexpected exit. The CDataRecoveryHandler Class handles storing the list of open documents and restoring them.
- AFX_RESTART_MANAGER_RESTORE_AUTOSAVED_FILES	The restart manager prompts the user to restore autosaved files after restarting the application. The CDataRecoveryHandler class queries the user.
- AFX_RESTART_MANAGER_SUPPORT_NO_AUTOSAVE	The union of AFX_RESTART_MANAGER_SUPPORT_RESTART, AFX_RESTART_MANAGER_SUPPORT_RECOVER, and AFX_RESTART_MANAGER_REOPEN_PREVIOUS_FILES.
- AFX_RESTART_MANAGER_SUPPORT_ALL_ASPECTS	The union of AFX_RESTART_MANAGER_SUPPORT_NO_AUTOSAVE, AFX_RESTART_MANAGER_AUTOSAVE_AT_RESTART, AFX_RESTART_MANAGER_AUTOSAVE_AT_INTERVAL, and AFX_RESTART_MANAGER_RESTORE_AUTOSAVED_FILES.
- AFX_RESTART_MANAGER_SUPPORT_RESTART_ASPECTS	The union of AFX_RESTART_MANAGER_SUPPORT_RESTART, AFX_RESTART_MANAGER_AUTOSAVE_AT_RESTART, AFX_RESTART_MANAGER_REOPEN_PREVIOUS_FILES, and AFX_RESTART_MANAGER_RESTORE_AUTOSAVED_FILES.
- AFX_RESTART_MANAGER_SUPPORT_RECOVERY_ASPECTS	The union of AFX_RESTART_MANAGER_SUPPORT_RECOVERY, AFX_RESTART_MANAGER_AUTOSAVE_AT_INTERVAL, AFX_RESTART_MANAGER_REOPEN_PREVIOUS_FILES, and AFX_RESTART_MANAGER_RESTORE_AUTOSAVED_FILES.

CWinApp::m_eHelpType

The type of this data member is the enumerated type AFX_HELP_TYPE, which is defined within the CWinApp class.

AFX_HELP_TYPE m_eHelpType;  

Remarks

The AFX_HELP_TYPE enumeration is defined as follows:

enum AFX_HELP_TYPE

{

afxWinHelp = 0,

afxHTMLHelp = 1

};

• To set the application's help to HTML Help, call SetHelpMode and specify afxHTMLHelp.

• To set the application's help to WinHelp, call SetHelpMode and specify afxWinHelp.

CWinApp::m_hInstance

Corresponds to the hInstance parameter passed by Windows to WinMain.

HINSTANCE m_hInstance;  

Remarks

The m_hInstance data member is a handle to the current instance of the application running under Windows. This is returned by the global function [AfxGetInstanceHandle]--brokenlink--(../Topic/not%20found.md#afxgetinstancehandle). m_hInstance is a public variable of type HINSTANCE.

Example

   // Typically you do not need to pass the application's hInstance
   // to Windows APIs directly because there are equivalent MFC
   // member functions that pass the hInstance for you.  The following
   // example is not typical:

   HCURSOR hCursor;
   hCursor = ::LoadCursor(AfxGetApp()->m_hInstance, 
      MAKEINTRESOURCE(IDC_MYCURSOR));

   // A more direct way to get the application's hInstance is to
   // call AfxGetInstanceHandle:
   hCursor = ::LoadCursor(AfxGetInstanceHandle(), 
      MAKEINTRESOURCE(IDC_MYCURSOR));

   // If you need the hInstance to load a resource, it is better
   // to call AfxGetResourceHandle instead of AfxGetInstanceHandle:
   hCursor = ::LoadCursor(AfxGetResourceHandle(), 
      MAKEINTRESOURCE(IDC_MYCURSOR));

   // A better way to load the cursor resource is to call
   // CWinApp::LoadCursor
   hCursor = AfxGetApp()->LoadCursor(IDC_MYCURSOR);

CWinApp::m_lpCmdLine

Corresponds to the lpCmdLine parameter passed by Windows to WinMain.

LPTSTR m_lpCmdLine;  

Remarks

Points to a null-terminated string that specifies the command line for the application. Use m_lpCmdLine to access any command-line arguments the user entered when the application was started. m_lpCmdLine is a public variable of type LPTSTR.

Example

   if (m_lpCmdLine[0] == _T('\0'))
   {
      // Create a new (empty) document.
      OnFileNew();
   }
   else
   {
      // Open a file passed as the first command line parameter.
      OpenDocumentFile(m_lpCmdLine);
   }

CWinApp::m_nAutosaveInterval

The length of time in milliseconds between autosaves.

int m_nAutosaveInterval;  

Remarks

You can configure the restart manager to autosave open documents at set intervals. If your application does not autosave files, this parameter has no effect.

CWinApp::m_nCmdShow

Corresponds to the nCmdShow parameter passed by Windows to WinMain.

int m_nCmdShow;  

Remarks

You should pass m_nCmdShow as an argument when you call CWnd::ShowWindow for your application's main window. m_nCmdShow is a public variable of type int.

Example

   // The following code fragment is taken from CMyApp::InitInstance.
   // CMyApp is derived from CWinApp.

    // The main window has been initialized, so show and update it
   // using the nCmdShow parameter passed to the application when it
   // was first launched.
   // pMainFrame is the main MDI frame window of our app and is derived 
   // from CMDIFrameWnd.
    pMainFrame->ShowWindow(m_nCmdShow);
    pMainFrame->UpdateWindow();

CWinApp::m_pActiveWnd

Use this data member to store a pointer to the main window of the OLE container application that has your OLE server application in-place activated.

Remarks

If this data member is NULL, the application is not in-place active.

The framework sets this member variable when the frame window is in-place activated by an OLE container application.

CWinApp::m_pDataRecoveryHandler

Pointer to the data recovery handler for the application.

CDataRecoveryHandler* m_pDataRecoveryHandler;  

Remarks

The data recovery handler of an application monitors open documents and autosaves them. The framework uses the data recovery handler to restore autosaved files when an application restarts after it exits unexpectedly. For more information, see CDataRecoveryHandler Class.

CWinApp::m_pszAppName

Specifies the name of the application.

LPCTSTR m_pszAppName;  

Remarks

The application name can come from the parameter passed to the CWinApp constructor, or, if not specified, to the resource string with the ID of AFX_IDS_APP_TITLE. If the application name is not found in the resource, it comes from the program's .EXE filename.

Returned by the global function [AfxGetAppName]--brokenlink--(../Topic/not%20found.md#afxgetappname). m_pszAppName is a public variable of type const char*.

   //First free the string allocated by MFC at CWinApp startup.
   //The string is allocated before InitInstance is called.
   free((void*)m_pszAppName);
   //Change the name of the application file.
   //The CWinApp destructor will free the memory.
   m_pszAppName = _tcsdup(_T("c:\\somedir\\myapp.exe"));

Example

   CWnd* pWnd = AfxGetMainWnd();
   // Set pWnd to some CWnd object whose window has already
   // been created.

   // The following call to CWnd::MessageBox uses the application
   // title as the message box caption.
   pWnd->MessageBox(_T("Some message"), AfxGetApp()->m_pszAppName);

   // A more direct way to get the application title is to 
   // call AfxGetAppName:
   pWnd->MessageBox(_T("Some message"), AfxGetAppName());

   // An easier way to display a message box using the application
   // title as the message box caption is to call AfxMessageBox:
   AfxMessageBox(_T("Some message"));

CWinApp::m_pszExeName

Contains the name of the application's executable file without an extension.

LPCTSTR m_pszExeName;  

Remarks

Unlike m_pszAppName, this name cannot contain blanks. m_pszExeName is a public variable of type const char*.

   //First free the string allocated by MFC at CWinApp startup.
   //The string is allocated before InitInstance is called.
   free((void*)m_pszExeName);
   //Change the name of the .EXE file.
   //The CWinApp destructor will free the memory.
   m_pszExeName = _tcsdup(_T("c:\\somedir\\myapp"));

CWinApp::m_pszHelpFilePath

Contains the path to the application's Help file.

LPCTSTR m_pszHelpFilePath;  

Remarks

By default, the framework initializes m_pszHelpFilePath to the name of the application with ".HLP" appended. To change the name of the help file, set m_pszHelpFilePath to point to a string that contains the complete name of the desired help file. A convenient place to do this is in the application's InitInstance function. m_pszHelpFilePath is a public variable of type const char*.

   //First free the string allocated by MFC at CWinApp startup.
   //The string is allocated before InitInstance is called.
   free((void*)m_pszHelpFilePath);
   //Change the name of the .HLP file.
   //The CWinApp destructor will free the memory.
   m_pszHelpFilePath = _tcsdup(_T("c:\\somedir\\myhelp.hlp"));

CWinApp::m_pszProfileName

Contains the name of the application's .INI file.

LPCTSTR m_pszProfileName;  

Remarks

m_pszProfileName is a public variable of type const char*.

   //First free the string allocated by MFC at CWinApp startup.
   //The string is allocated before InitInstance is called.
   free((void*)m_pszProfileName);
   //Change the name of the .INI file.
   //The CWinApp destructor will free the memory.
   m_pszProfileName = _tcsdup(_T("c:\\somedir\\myini.ini"));

CWinApp::m_pszRegistryKey

Used to determine where, in the registry or INI file, application profile settings are stored.

LPCTSTR m_pszRegistryKey;  

Remarks

Normally, this data member is treated as read-only.

• The value is stored to a registry key. The name for the application profile setting is appended to the following registry key: HKEY_CURRENT_USER/Software/LocalAppWizard-Generated/.

If you assign a value to m_pszRegistryKey, it must be dynamically allocated on the heap. The CWinApp destructor calls free( ) with this pointer. You many want to use the _tcsdup( ) run-time library function to do the allocating. Also, free the memory associated with the current pointer before assigning a new value. For example:

   //First free the string allocated by MFC at CWinApp startup.
   //The string is allocated before InitInstance is called.
   free((void*)m_pszRegistryKey);
   //Change the name of the registry key.
   //The CWinApp destructor will free the memory.
   m_pszRegistryKey = _tcsdup(
      _T("HKEY_CURRENT_USER\\Software\\mycompany\\myapp\\thissection\\thisvalue"));

CWinApp::m_pszAppID

Application User Model ID.

LPCTSTR m_pszAppID;  

Remarks

CWinApp::OnContextHelp

Handles SHIFT+F1 Help within the application.

afx_msg void OnContextHelp();

Remarks

You must add an ON_COMMAND( ID_CONTEXT_HELP, OnContextHelp ) statement to your CWinApp class message map and also add an accelerator table entry, typically SHIFT+F1, to enable this member function.

OnContextHelp puts the application into Help mode. The cursor changes to an arrow and a question mark, and the user can then move the mouse pointer and press the left mouse button to select a dialog box, window, menu, or command button. This member function retrieves the Help context of the object under the cursor and calls the Windows function WinHelp with that Help context.

CWinApp::OnDDECommand

Called by the framework when the main frame window receives a DDE execute message.

virtual BOOL OnDDECommand(LPTSTR lpszCommand);

Parameters

lpszCommand
Points to a DDE command string received by the application.

Return Value

Nonzero if the command is handled; otherwise 0.

Remarks

The default implementation checks whether the command is a request to open a document and, if so, opens the specified document. The Windows File Manager usually sends such DDE command strings when the user double-clicks a data file. Override this function to handle other DDE execute commands, such as the command to print.

Example

BOOL CMyApp::OnDDECommand(LPTSTR lpszCommand)
{
   if (CWinApp::OnDDECommand(lpszCommand))
      return TRUE;

   // Handle any DDE commands recognized by your application
   // and return TRUE.  See implementation of CWinApp::OnDDEComand
   // for example of parsing the DDE command string.

   // Return FALSE for any DDE commands you do not handle.
   return FALSE;
 }

CWinApp::OnFileNew

Implements the ID_FILE_NEW command.

afx_msg void OnFileNew();

Remarks

You must add an ON_COMMAND( ID_FILE_NEW, OnFileNew ) statement to your CWinApp class message map to enable this member function. If enabled, this function handles execution of the File New command.

See Technical Note 22 for information on default behavior and guidance on how to override this member function.

Example

// The following message map, produced by the Application Wizard, binds 
// the File New, Open, and Print Setup menu commands to default
// framework implementations of these commands.
BEGIN_MESSAGE_MAP(CStdApp, CWinApp)
   // Standard file based document commands
   ON_COMMAND(ID_FILE_NEW, &CWinApp::OnFileNew)
   ON_COMMAND(ID_FILE_OPEN, &CWinApp::OnFileOpen)
   // Standard print setup command
   ON_COMMAND(ID_FILE_PRINT_SETUP, &CWinApp::OnFilePrintSetup)
END_MESSAGE_MAP()

// The following message map illustrates how to rebind the
// File New, Open and Print Setup menu commands to handlers that
// you implement in your CWinApp-derived class.  
// Note, you can name the handler CCustomApp::OnFileNew instead of
// CCustomApp::OnMyFileNew, and likewise for the other handlers, if desired.
BEGIN_MESSAGE_MAP(CCustomApp, CWinApp)
   ON_COMMAND(ID_FILE_NEW, &CCustomApp::OnMyFileNew)
   ON_COMMAND(ID_FILE_OPEN, &CCustomApp::OnMyFileOpen)
   ON_COMMAND(ID_FILE_PRINT_SETUP, &CCustomApp::OnMyFilePrintSetup)
END_MESSAGE_MAP()

CWinApp::OnFileOpen

Implements the ID_FILE_OPEN command.

afx_msg void OnFileOpen();

Remarks

You must add an ON_COMMAND( ID_FILE_OPEN, OnFileOpen ) statement to your CWinApp class message map to enable this member function. If enabled, this function handles execution of the File Open command.

For information on default behavior and guidance on how to override this member function, see Technical Note 22.

Example

// The following message map, produced by the Application Wizard, binds 
// the File New, Open, and Print Setup menu commands to default
// framework implementations of these commands.
BEGIN_MESSAGE_MAP(CStdApp, CWinApp)
   // Standard file based document commands
   ON_COMMAND(ID_FILE_NEW, &CWinApp::OnFileNew)
   ON_COMMAND(ID_FILE_OPEN, &CWinApp::OnFileOpen)
   // Standard print setup command
   ON_COMMAND(ID_FILE_PRINT_SETUP, &CWinApp::OnFilePrintSetup)
END_MESSAGE_MAP()

// The following message map illustrates how to rebind the
// File New, Open and Print Setup menu commands to handlers that
// you implement in your CWinApp-derived class.  
// Note, you can name the handler CCustomApp::OnFileNew instead of
// CCustomApp::OnMyFileNew, and likewise for the other handlers, if desired.
BEGIN_MESSAGE_MAP(CCustomApp, CWinApp)
   ON_COMMAND(ID_FILE_NEW, &CCustomApp::OnMyFileNew)
   ON_COMMAND(ID_FILE_OPEN, &CCustomApp::OnMyFileOpen)
   ON_COMMAND(ID_FILE_PRINT_SETUP, &CCustomApp::OnMyFilePrintSetup)
END_MESSAGE_MAP()

CWinApp::OnFilePrintSetup

Implements the ID_FILE_PRINT_SETUP command.

afx_msg void OnFilePrintSetup();

Remarks

You must add an ON_COMMAND( ID_FILE_PRINT_SETUP, OnFilePrintSetup ) statement to your CWinApp class message map to enable this member function. If enabled, this function handles execution of the File Print command.

For information on default behavior and guidance on how to override this member function, see Technical Note 22.

Example

// The following message map, produced by the Application Wizard, binds 
// the File New, Open, and Print Setup menu commands to default
// framework implementations of these commands.
BEGIN_MESSAGE_MAP(CStdApp, CWinApp)
   // Standard file based document commands
   ON_COMMAND(ID_FILE_NEW, &CWinApp::OnFileNew)
   ON_COMMAND(ID_FILE_OPEN, &CWinApp::OnFileOpen)
   // Standard print setup command
   ON_COMMAND(ID_FILE_PRINT_SETUP, &CWinApp::OnFilePrintSetup)
END_MESSAGE_MAP()

// The following message map illustrates how to rebind the
// File New, Open and Print Setup menu commands to handlers that
// you implement in your CWinApp-derived class.  
// Note, you can name the handler CCustomApp::OnFileNew instead of
// CCustomApp::OnMyFileNew, and likewise for the other handlers, if desired.
BEGIN_MESSAGE_MAP(CCustomApp, CWinApp)
   ON_COMMAND(ID_FILE_NEW, &CCustomApp::OnMyFileNew)
   ON_COMMAND(ID_FILE_OPEN, &CCustomApp::OnMyFileOpen)
   ON_COMMAND(ID_FILE_PRINT_SETUP, &CCustomApp::OnMyFilePrintSetup)
END_MESSAGE_MAP()

CWinApp::OnHelp

Handles F1 Help within the application (using the current context).

afx_msg void OnHelp();

Remarks

Usually you will also add an accelerator-key entry for the F1 key. Enabling the F1 key is only a convention, not a requirement.

You must add an ON_COMMAND( ID_HELP, OnHelp ) statement to your CWinApp class message map to enable this member function. If enabled, called by the framework when the user presses the F1 key.

The default implementation of this message-handler function determines the Help context that corresponds to the current window, dialog box, or menu item and then calls WINHELP.EXE. If no context is currently available, the function uses the default context.

Override this member function to set the Help context to something other than the window, dialog box, menu item, or toolbar button that currently has the focus. Call WinHelp with the desired Help context ID.

CWinApp::OnHelpFinder

Handles the ID_HELP_FINDER and ID_DEFAULT_HELP commands.

afx_msg void OnHelpFinder();

Remarks

You must add an ON_COMMAND( ID_HELP_FINDER, OnHelpFinder ) statement to your CWinApp class message map to enable this member function. If enabled, the framework calls this message-handler function when the user of your application selects the Help Finder command to invoke WinHelp with the standard HELP_FINDER topic.

CWinApp::OnHelpIndex

Handles the ID_HELP_INDEX command and provides a default Help topic.

afx_msg void OnHelpIndex();

Remarks

You must add an ON_COMMAND( ID_HELP_INDEX, OnHelpIndex ) statement to your CWinApp class message map to enable this member function. If enabled, the framework calls this message-handler function when the user of your application selects the Help Index command to invoke WinHelp with the standard HELP_INDEX topic.

CWinApp::OnHelpUsing

Handles the ID_HELP_USING command.

afx_msg void OnHelpUsing();

Remarks

You must add an ON_COMMAND( ID_HELP_USING, OnHelpUsing ) statement to your CWinApp class message map to enable this member function. The framework calls this message-handler function when the user of your application selects the Help Using command to invoke the WinHelp application with the standard HELP_HELPONHELP topic.

CWinApp::OnIdle

Override this member function to perform idle-time processing.

virtual BOOL OnIdle(LONG lCount);

Parameters

lCount
A counter incremented each time OnIdle is called when the application's message queue is empty. This count is reset to 0 each time a new message is processed. You can use the lCount parameter to determine the relative length of time the application has been idle without processing a message.

Return Value

Nonzero to receive more idle processing time; 0 if no more idle time is needed.

Remarks

OnIdle is called in the default message loop when the application's message queue is empty. Use your override to call your own background idle-handler tasks.

OnIdle should return 0 to indicate that no idle processing time is required. The lCount parameter is incremented each time OnIdle is called when the message queue is empty and resets to 0 each time a new message is processed. You can call your different idle routines based on this count.

The following summarizes idle loop processing:

1. If the message loop in the Microsoft Foundation Class Library checks the message queue and finds no pending messages, it calls OnIdle for the application object and supplies 0 as the lCount argument.

2. OnIdle performs some processing and returns a nonzero value to indicate it should be called again to do further processing.

3. The message loop checks the message queue again. If no messages are pending, it calls OnIdle again, incrementing the lCount argument.

4. Eventually, OnIdle finishes processing all its idle tasks and returns 0. This tells the message loop to stop calling OnIdle until the next message is received from the message queue, at which point the idle cycle restarts with the argument set to 0.

Do not perform lengthy tasks during OnIdle because your application cannot process user input until OnIdle returns.

If you do not want OnIdle to be called whenever a message is retrieved from the message queue, you can override the CWinThreadIsIdleMessage. If an application has set a very short timer, or if the system is sending the WM_SYSTIMER message, then OnIdle will be called repeatedly, and degrade performance.

Example

The following two examples show how to use OnIdle. The first example processes two idle tasks using the lCount argument to prioritize the tasks. The first task is high priority, and you should do it whenever possible. The second task is less important and should be done only when there is a long pause in user input. Note the call to the base-class version of OnIdle. The second example manages a group of idle tasks with different priorities.

BOOL CMyApp::OnIdle(LONG lCount)
{
   BOOL bMore = CWinApp::OnIdle(lCount);

   if (lCount == 0)
   {
      TRACE(_T("App idle for short period of time\n"));
      bMore = TRUE;
   }
   else if (lCount == 10)
   {
      TRACE(_T("App idle for longer amount of time\n"));
      bMore = TRUE;
   }
   else if (lCount == 100)
   {
      TRACE(_T("App idle for even longer amount of time\n"));
      bMore = TRUE;
   }
   else if (lCount == 1000)
   {
      TRACE(_T("App idle for quite a long period of time\n"));
      // bMore is not set to TRUE, no longer need idle
      // IMPORTANT: bMore is not set to FALSE since CWinApp::OnIdle may
      // have more idle tasks to complete.
   }

   return bMore;
   // return TRUE as long as there are any more idle tasks
}

CWinApp::OpenDocumentFile

The framework calls this method to open the named CDocument file for the application.

virtual CDocument* OpenDocumentFile(
LPCTSTR lpszFileName  
BOOL bAddToMRU = TRUE);

Parameters

[in] lpszFileName
The name of the file to be opened.

[in] bAddToMRU
TRUE indicates the document is one of the most recent files; FALSE indicates the document is not one of the most recent files.

Return Value

A pointer to a CDocument if successful; otherwise NULL.

Remarks

If a document that has that name is already open, the first frame window that contains that document will get the focus. If an application supports multiple document templates, the framework uses the file name extension to find the appropriate document template to try to load the document. If successful, the document template then creates a frame window and view for the document.

Example

   if (m_lpCmdLine[0] == _T('\0'))
   {
      // Create a new (empty) document.
      OnFileNew();
   }
   else
   {
      // Open a file passed as the first command line parameter.
      OpenDocumentFile(m_lpCmdLine);
   }

CWinApp::ParseCommandLine

Call this member function to parse the command line and send the parameters, one at a time, to CCommandLineInfo::ParseParam.

void ParseCommandLine(CCommandLineInfo& rCmdInfo);

Parameters

rCmdInfo
A reference to a CCommandLineInfo object.

Remarks

When you start a new MFC project using the Application Wizard, the Application Wizard will create a local instance of CCommandLineInfo, and then call ProcessShellCommand and ParseCommandLine in the InitInstance member function. A command line follows the route described below:

1. After being created in InitInstance, the CCommandLineInfo object is passed to ParseCommandLine.

2. ParseCommandLine then calls CCommandLineInfo::ParseParam repeatedly, once for each parameter.

3. ParseParam fills the CCommandLineInfo object, which is then passed to ProcessShellCommand.

4. ProcessShellCommand handles the command-line arguments and flags.

Note that you can call ParseCommandLine directly as needed.

For a description of the command-line flags, see CCommandLineInfo::m_nShellCommand.

CWinApp::PreTranslateMessage

Override this function to filter window messages before they are dispatched to the Windows functions TranslateMessage and DispatchMessage The default implementation performs accelerator-key translation, so you must call the CWinApp::PreTranslateMessage member function in your overridden version.

virtual BOOL PreTranslateMessage(MSG* pMsg);

Parameters

pMsg
A pointer to a MSG structure that contains the message to process.

Return Value

Nonzero if the message was fully processed in PreTranslateMessage and should not be processed further. Zero if the message should be processed in the normal way.

CWinApp::ProcessMessageFilter

The framework's hook function calls this member function to filter and respond to certain Windows messages.

virtual BOOL ProcessMessageFilter(
    int code,  
    LPMSG lpMsg);

Parameters

code
Specifies a hook code. This member function uses the code to determine how to process lpMsg.

lpMsg
A pointer to a Windows MSG structure.

Return Value

Nonzero if the message is processed; otherwise 0.

Remarks

A hook function processes events before they are sent to the application's normal message processing.

If you override this advanced feature, be sure to call the base-class version to maintain the framework's hook processing.

CWinApp::ProcessShellCommand

This member function is called by InitInstance to accept the parameters passed from the CCommandLineInfo object identified by rCmdInfo, and perform the indicated action.

BOOL ProcessShellCommand(CCommandLineInfo& rCmdInfo);

Parameters

rCmdInfo
A reference to a CCommandLineInfo object.

Return Value

Nonzero if the shell command is processed successfully. If 0, return FALSE from InitInstance.

Remarks

When you start a new MFC project using the Application Wizard, the Application Wizard will create a local instance of CCommandLineInfo, and then call ProcessShellCommand and ParseCommandLine in the InitInstance member function. A command line follows the route described below:

1. After being created in InitInstance, the CCommandLineInfo object is passed to ParseCommandLine.

2. ParseCommandLine then calls CCommandLineInfo::ParseParam repeatedly, once for each parameter.

3. ParseParam fills the CCommandLineInfo object, which is then passed to ProcessShellCommand.

4. ProcessShellCommand handles the command-line arguments and flags.

The data members of the CCommandLineInfo object, identified by CCommandLineInfo::m_nShellCommand, are of the following enumerated type, which is defined within the CCommandLineInfo class.

enum {

FileNew,

FileOpen,

FilePrint,

FilePrintTo,

FileDDE,

};

For a brief description of each of these values, see CCommandLineInfo::m_nShellCommand.

CWinApp::ProcessWndProcException

The framework calls this member function whenever the handler does not catch an exception thrown in one of your application's message or command handlers.

virtual LRESULT ProcessWndProcException(
    CException* e,  
    const MSG* pMsg);

Parameters

e
A pointer to an uncaught exception.

pMsg
A MSG structure that contains information about the windows message that caused the framework to throw an exception.

Return Value

The value that should be returned to Windows. Normally this is 0L for windows messages, 1L ( TRUE) for command messages.

Remarks

Do not call this member function directly.

The default implementation of this member function creates a message box. If the uncaught exception originates with a menu, toolbar, or accelerator command failure, the message box displays a "Command failed" message; otherwise, it displays an "Internal application error" message.

Override this member function to provide global handling of your exceptions. Only call the base functionality if you wish the message box to be displayed.

CWinApp::Register

Performs any registration tasks not handled by RegisterShellFileTypes.

virtual BOOL Register();

Return Value

Nonzero on success; otherwise 0.

Remarks

The default implementation simply returns TRUE. Override this function to provide any customized registration steps.

CWinApp::RegisterShellFileTypes

Call this member function to register all of your application's document types with the Windows File Manager.

void RegisterShellFileTypes(BOOL bCompat = FALSE);

Parameters

[in] bCompat
TRUE adds registration entries for shell commands Print and Print To, allowing a user to print files directly from the shell, or by dragging the file to a printer object. It also adds a DefaultIcon key. By default, this parameter is FALSE for backward compatibility.

Remarks

This allows the user to open a data file created by your application by double-clicking it from within File Manager. Call RegisterShellFileTypes after you call AddDocTemplate for each of the document templates in your application. Also call the EnableShellOpen member function when you call RegisterShellFileTypes.

RegisterShellFileTypes iterates through the list of CDocTemplate objects that the application maintains and, for each document template, adds entries to the registration database that Windows maintains for file associations. File Manager uses these entries to open a data file when the user double-clicks it. This eliminates the need to ship a .REG file with your application.

If the registration database already associates a given filename extension with another file type, no new association is created. See the CDocTemplate class for the format of strings necessary to register this information.

CWinApp::RegisterWithRestartManager

Registers the application with the restart manager.

virtual HRESULT RegisterWithRestartManager(
BOOL bRegisterRecoveryCallback,  
const CString& strRestartIdentifier);

 
virtual HRESULT RegisterWithRestartManager(
LPCWSTR pwzCommandLineArgs,  
DWORD dwRestartFlags,  
APPLICATION_RECOVERY_CALLBACK pRecoveryCallback,  
LPVOID lpvParam,  
DWORD dwPingInterval,  
DWORD dwCallbackFlags);

Parameters

Parameter	Description
[in] bRegisterRecoveryCallback	TRUE indicates that this instance of the application uses a recovery callback function; FALSE indicates that it does not. The framework calls the recovery callback function when the application exits unexpectedly. For more information, see CWinApp::ApplicationRecoveryCallback.
[in] strRestartIdentifier	The unique string that identifies this instance of the restart manager. The restart manager identifier is unique for each instance of an application.
[in] pwzCommandLineArgs	A string that contains any extra arguments from the command line.
[in] dwRestartFlags	Optional flags for the restart manager. For more information, see the Remarks section.
[in] pRecoveryCallback	The recovery callback function. This function must take a LPVOID parameter as input and return a DWORD. The default recovery callback function is CWinApp::ApplicationRecoveryCallback.
[in] lpvParam	The input parameter for the recovery callback function. For more information, see CWinApp::ApplicationRecoveryCallback.
[in] dwPingInterval	The length of time that the restart manager waits for the recovery callback function to return. This parameter is in milliseconds.
[in] dwCallbackFlags	Flags passed to the recovery callback function. Reserved for future use.

Return Value

S_OK if the method is successful; otherwise an error code.

Remarks

If your application uses the default MFC implementation for autosaving files, you should use the simple version of RegisterWithRestartManager. Use the complex version of RegisterWithRestartManager if you want to customize the autosave behavior of your application.

If you call this method with an empty string for strRestartIdentifier, RegisterWithRestartManager creates a unique identifier string for this instance of the restart manager.

When an application exits unexpectedly, the restart manager restarts the application from the command line and provides the unique restart identifier as an optional argument. In this scenario, the framework calls RegisterWithRestartManager two times. The first call comes from CWinApp::InitInstance with an empty string for the string identifier. Then, the method CWinApp::ProcessShellCommand calls RegisterWithRestartManager with the unique restart identifier.

After you register an application with the restart manager, the restart manager monitors the application. If the application exits unexpectedly, the restart manager calls the recovery callback function during the shut down process. The restart manager waits the dwPingInterval for a response from the recovery callback function. If the recovery callback function does not respond within this time, the application exits without executing the recovery callback function.

By default, the dwRestartFlags are not supported but are provided for future use. The possible values for dwRestartFlags are as follows:

• RESTART_NO_CRASH

• RESTART_NO_HANG

• RESTART_NO_PATCH

• RESTART_NO_REBOOT

CWinApp::ReopenPreviousFilesAtRestart

Determines whether the restart manager reopens the files that were open when the application exited unexpectedly.

virtual BOOL ReopenPreviousFilesAtRestart() const;  

Return Value

TRUE indicates the restart manager reopens the previously open files; FALSE indicates the restart manager does not.

CWinApp::RestartInstance

Handles an application restart initiated by the restart manager.

virtual BOOL CWinApp::RestartInstance();

Return Value

TRUE if the data recovery handler opens previously open documents; FALSE if the data recovery handler has an error or if there are no previously open documents.

Remarks

When the restart manager restarts an application, the framework calls this method. This method retrieves the data recovery handler and restores the autosaved files. This method calls CDataRecoveryHandler::RestoreAutosavedDocuments to determine whether the user wants to restore the autosaved files.

This method returns FALSE if the CDataRecoveryHandler determines that there were no open documents. If there were no open documents, the application starts ordinarily.

CWinApp::RestoreAutosavedFilesAtRestart

Determines whether the restart manager restores the autosaved files when it restarts the application.

virtual BOOL RestoreAutosavedFilesAtRestart() const;  

Return Value

TRUE indicates the restart manager restores autosaved files; FALSE indicates the restart manager does not.

CWinApp::Run

Provides a default message loop.

virtual int Run();

Return Value

An int value that is returned by WinMain.

Remarks

Run acquires and dispatches Windows messages until the application receives a WM_QUIT message. If the application's message queue currently contains no messages, Run calls OnIdle to perform idle-time processing. Incoming messages go to the PreTranslateMessage member function for special processing and then to the Windows function TranslateMessage for standard keyboard translation; finally, the DispatchMessage Windows function is called.

Run is rarely overridden, but you can override it to provide special behavior.

CWinApp::RunAutomated

Call this function to determine whether the " /Automation" or " -Automation" option is present, which indicates whether the server application was launched by a client application.

BOOL RunAutomated();

Return Value

Nonzero if the option was found; otherwise 0.

Remarks

If present, the option is removed from the command line. For more information on OLE Automation, see the article Automation Servers.

CWinApp::RunEmbedded

Call this function to determine whether the " /Embedding" or " -Embedding" option is present, which indicates whether the server application was launched by a client application.

BOOL RunEmbedded();

Return Value

Nonzero if the option was found; otherwise 0.

Remarks

If present, the option is removed from the command line. For more information on embedding, see the article Servers: Implementing a Server.

CWinApp::SaveAllModified

Called by the framework to save all documents when the application's main frame window is to be closed, or through a WM_QUERYENDSESSION message.

virtual BOOL SaveAllModified();

Return Value

Nonzero if safe to terminate the application; 0 if not safe to terminate the application.

Remarks

The default implementation of this member function calls the CDocument::SaveModified member function in turn for all modified documents within the application.

CWinApp::SelectPrinter

Call this member function to select a specific printer, and release the printer that was previously selected in the Print Dialog box.

void SelectPrinter(
    HANDLE hDevNames,  
    HANDLE hDevMode,  
    BOOL bFreeOld = TRUE);

Parameters

hDevNames
A handle to a DEVNAMES structure that identifies the driver, device, and output port names of a specific printer.

hDevMode
A handle to a DEVMODE structure that specifies information about the device initialization and environment of a printer.

bFreeOld
Frees the previously-selected printer.

Remarks

If both hDevMode and hDevNames are NULL, SelectPrinter uses the current default printer.

CWinApp::SetHelpMode

Sets the application's help type.

void SetHelpMode(AFX_HELP_TYPE eHelpType);

Parameters

eHelpType
Specifies the type of help to use. See CWinApp::m_eHelpType for more information.

Remarks

Sets the application's Help type.

To set your application's Help type to HTMLHelp, you can call EnableHTMLHelp. Once you call EnableHTMLHelp, your application must use HTMLHelp as its help application. If you want to change to use WinHelp, you can call SetHelpMode and set eHelpType to afxWinHelp.

CWinApp::SetRegistryKey

Causes application settings to be stored in the registry instead of INI files.

void SetRegistryKey(LPCTSTR lpszRegistryKey);  
void SetRegistryKey(UINT nIDRegistryKey);
```  
  
### Parameters  
 *lpszRegistryKey*  
 Pointer to a string containing the name of the key.  
  
 *nIDRegistryKey*  
 ID of a string resource containing the name of the registry key.  
  
### Remarks  
 This function sets *m_pszRegistryKey*, which is then used by the `GetProfileInt`, `GetProfileString`, `WriteProfileInt`, and `WriteProfileString` member functions of `CWinApp`. If this function has been called, the list of most recently-used (MRU) files is also stored in the registry. The registry key is usually the name of a company. It is stored in a key of the following form: HKEY_CURRENT_USER\Software\\<company name\>\\<application name\>\\<section name\>\\<value name\>.  
  
##  <a name="cwinapp__supportsapplicationrecovery"></a>  CWinApp::SupportsApplicationRecovery  
 Determines whether the restart manager recovers an application that exited unexpectedly.  
  

virtual BOOL SupportsApplicationRecovery() const;

  
### Return Value  
 `TRUE` indicates the restart manager recovers the application; `FALSE` indicates the restart manager does not.  
  
##  <a name="cwinapp__supportsautosaveatinterval"></a>  CWinApp::SupportsAutosaveAtInterval  
 Determines whether the restart manager autosaves open documents at a regular interval.  
  

virtual BOOL SupportsAutosaveAtInterval() const;

  
### Return Value  
 `TRUE` indicates the restart manager autosaves open documents; `FALSE` indicates the restart manager does not.  
  
##  <a name="cwinapp__supportsautosaveatrestart"></a>  CWinApp::SupportsAutosaveAtRestart  
 Determines whether the restart manager autosaves any open documents when the application restarts.  
  

virtual BOOL SupportsAutosaveAtRestart() const;

  
### Return Value  
 `TRUE` indicates the restart manager autosaves open documents when the application restarts; `FALSE` indicates the restart manager does not.  
  
##  <a name="cwinapp__supportsrestartmanager"></a>  CWinApp::SupportsRestartManager  
 Determines whether the application supports the restart manager.  
  

virtual BOOL SupportsRestartManager() const;

  
### Return Value  
 `TRUE` indicates the application supports the restart manager; `FALSE` indicates the application does not.  
  
##  <a name="cwinapp__unregister"></a>  CWinApp::Unregister  
 Unregisters all files registered by the application object.  
  

virtual BOOL Unregister();

  
### Return Value  
 Nonzero on success; otherwise 0.  
  
### Remarks  
 The `Unregister` function undoes the registration performed by the application object and the [Register](#cwinapp__register) function. Normally, both functions are called implicitly by MFC and therefore will not appear in your code.  
  
 Override this function to perform custom unregistration steps.  
  
##  <a name="cwinapp__unregistershellfiletypes"></a>  CWinApp::UnregisterShellFileTypes  
 Call this member function to unregister all of your application's document types with the Windows File Manager.  
  

void UnregisterShellFileTypes();

  
##  <a name="cwinapp__winhelp"></a>  CWinApp::WinHelp  
 Call this member function to invoke the WinHelp application.  
  

virtual void WinHelp( DWORD_PTR dwData,
UINT nCmd = HELP_CONTEXT);

  
### Parameters  
 `dwData`  
 Specifies additional data. The value used depends on the value of the `nCmd` parameter.  
  
 `nCmd`  
 Specifies the type of help requested. For a list of possible values and how they affect the `dwData` parameter, see the [WinHelp](https://msdn.microsoft.com/library/windows/desktop/bb762267) Windows function.  
  
### Remarks  
 The framework also calls this function to invoke the WinHelp application.  
  
 The framework will automatically close the WinHelp application when your application terminates.  
  
### Example  
 [!CODE [NVC_MFCWindowing#53](../CodeSnippet/VS_Snippets_Cpp/NVC_MFCWindowing#53)]  
  
##  <a name="cwinapp__writeprofilebinary"></a>  CWinApp::WriteProfileBinary  
 Call this member function to write binary data into the specified section of the application's registry or .INI file.  
  

BOOL WriteProfileBinary( LPCTSTR lpszSection,
LPCTSTR lpszEntry,
LPBYTE pData,
UINT nBytes);

  
### Parameters  
 `lpszSection`  
 Points to a null-terminated string that specifies the section containing the entry. If the section does not exist, it is created. The name of the section is case independent; the string may be any combination of uppercase and lowercase letters.  
  
 `lpszEntry`  
 Points to a null-terminated string that contains the entry into which the value is to be written. If the entry does not exist in the specified section, it is created.  
  
 `pData`  
 Points to the data to be written.  
  
 `nBytes`  
 Contains the number of bytes to be written.  
  
### Return Value  
 Nonzero if successful; otherwise 0.  
  
### Example  
 This example uses `CWinApp* pApp = AfxGetApp();` to get at the CWinApp class illustrating a way that `WriteProfileBinary` and `GetProfileBinary` can be used from any function in an MFC application.  
  
 [!CODE [NVC_MFCWindowing#54](../CodeSnippet/VS_Snippets_Cpp/NVC_MFCWindowing#54)]  
  
 For another example, see the example for [CWinApp::GetProfileBinary](#cwinapp__getprofilebinary).  
  
##  <a name="cwinapp__writeprofileint"></a>  CWinApp::WriteProfileInt  
 Call this member function to write the specified value into the specified section of the application's registry or .INI file.  
  

BOOL WriteProfileInt( LPCTSTR lpszSection,
LPCTSTR lpszEntry,
int nValue);

  
### Parameters  
 `lpszSection`  
 Points to a null-terminated string that specifies the section containing the entry. If the section does not exist, it is created. The name of the section is case independent; the string may be any combination of uppercase and lowercase letters.  
  
 `lpszEntry`  
 Points to a null-terminated string that contains the entry into which the value is to be written. If the entry does not exist in the specified section, it is created.  
  
 `nValue`  
 Contains the value to be written.  
  
### Return Value  
 Nonzero if successful; otherwise 0.  
  
### Example  
 This example uses `CWinApp* pApp = AfxGetApp();` to get at the CWinApp class illustrating a way that `WriteProfileString`, `WriteProfileInt`, `GetProfileString`, and `GetProfileInt` can be used from any function in an MFC application.  
  
 [!CODE [NVC_MFCWindowing#43](../CodeSnippet/VS_Snippets_Cpp/NVC_MFCWindowing#43)]  
  
 For another example, see the example for [CWinApp::GetProfileInt](#cwinapp__getprofileint).  
  
##  <a name="cwinapp__writeprofilestring"></a>  CWinApp::WriteProfileString  
 Call this member function to write the specified string into the specified section of the application's registry or .INI file.  
  

BOOL WriteProfileString( LPCTSTR lpszSection,
LPCTSTR lpszEntry,
LPCTSTR lpszValue);

  
### Parameters  
 `lpszSection`  
 Points to a null-terminated string that specifies the section containing the entry. If the section does not exist, it is created. The name of the section is case independent; the string may be any combination of uppercase and lowercase letters.  
  
 `lpszEntry`  
 Points to a null-terminated string that contains the entry into which the value is to be written. If the entry does not exist in the specified section, it is created. If this parameter is `NULL`, the section specified by `lpszSection` is deleted.  
  
 `lpszValue`  
 Points to the string to be written. If this parameter is `NULL`, the entry specified by the `lpszEntry` parameter is deleted.  
  
### Return Value  
 Nonzero if successful; otherwise 0.  
  
### Example  
 [!CODE [NVC_MFCWindowing#43](../CodeSnippet/VS_Snippets_Cpp/NVC_MFCWindowing#43)]  
  
 For another example, see the example for [CWinApp::GetProfileInt](#cwinapp__getprofileint).  
  
##  <a name="cwinapp__setappid"></a>  CWinApp::SetAppID  
 Explicitly sets Application User Model ID for the application. This method should be called before any user interface is presented to the user (the best place is the application constructor).  
  

void SetAppID(LPCTSTR lpcszAppID);

  
### Parameters  
 `lpcszAppID`  
 Specifies the Application User Model ID.  
  
### Remarks  
  
## See Also  
 [CWinThread Class](../Topic/CWinThread%20Class.md)   
 [Hierarchy Chart](../Topic/Hierarchy%20Chart.md)   
 [How to: Add Restart Manager Support](../Topic/How%20to:%20Add%20Restart%20Manager%20Support.md)