DialogProc

A version of this page is also available for

Windows Embedded CE 6.0 R3

4/8/2010

This function is an application-defined callback function that processes messages sent to a modal or modeless dialog box.

Syntax

BOOL CALLBACK DialogProc(
  HWND hwndDlg, 
  UINT uMsg, 
  WPARAM wParam, 
  LPARAM lParam
);

Parameters

• hwndDlg
  [in] Handle to the dialog box.

• uMsg
  [in] Specifies the message.

• wParam
  [in, out] Specifies additional message-specific information.

• lParam
  [in, out] Specifies additional message-specific information.

Return Value

Typically, the dialog box procedure should return TRUE if it processed the message, and FALSE if it did not. If the dialog box procedure returns FALSE, the dialog manager performs the default dialog operation in response to the message.

If the dialog box procedure processes a message that requires a specific return value, the dialog box procedure should set the desired return value by calling SetWindowLong (hwndDlg, DWL_MSGRESULT, lResult) immediately before returning TRUE. Note that you must call SetWindowLong immediately before returning TRUE; doing so earlier may result in the DWL_MSGRESULT value being overwritten by a nested dialog box message.

The following messages are exceptions to the general rules:

Consult the documentation for the specific message for details on the semantics of the return value.

Remarks

You should use the dialog box procedure only if you use the dialog box class for the dialog box. This is the default class and is used when no explicit class is specified in the dialog box template. Although the dialog box procedure is similar to a window procedure, it must not call the DefWindowProc function to process unwanted messages. Unwanted messages are processed internally by the dialog box window procedure.

Requirements

See Also

Reference

CreateDialog
CreateDialogIndirect
CreateDialogIndirectParam
CreateDialogParam
DefWindowProc
DialogBox
DialogBoxIndirect
DialogBoxIndirectParam
DialogBoxParam
SetFocus
MAKEINTRESOURCE
WM_INITDIALOG
Dialog Boxes Functions