IPortableDeviceServiceManager::GetDeviceServices method (portabledeviceapi.h)
The GetDeviceServices method retrieves a list of the services associated with the specified device.
Syntax
HRESULT GetDeviceServices(
[in] LPCWSTR pszPnPDeviceID,
[in] REFGUID guidServiceCategory,
[in, out] LPWSTR *pServices,
[in, out] DWORD *pcServices
);
Parameters
[in] pszPnPDeviceID
The Plug and Play (PnP) identifier of the device.
[in] guidServiceCategory
A reference to a globally unique identifier (GUID) that specifies the category of services to retrieve. If the referenced identifier is GUID_DEVINTERFACE_WPD_SERVICE, this method will retrieve all services supported by the device.
[in, out] pServices
A user-allocated array of pointers to strings. When the method returns, the array contains the retrieved PnP service identifiers.
[in, out] pcServices
The number of elements in the array specified by the pServices parameter. This value represents the maximum number of service identifiers that will be retrieved. When the method returns, this parameter contains the number of identifiers actually retrieved.
Return value
The method returns an HRESULT. Possible values include, but are not limited to, those in the following table.
| Return code | Description |
|---|---|
|
The method succeeded. |
|
The array referenced by the pServices parameter was too small to contain all of the services. |
|
The pcServices parameter was NULL. |
Remarks
If this method succeeds, the application should call the FreePortableDevicePnPIDs function to free the array referenced by the pServices parameter.
An application can retrieve the PnP identifier for a device by calling the IPortableDeviceManager::GetDevices method.
Applications that use Single Threaded Apartments should use CLSID_PortableDeviceServiceFTM as this eliminates the overhead of interface pointer marshaling. CLSID_PortableDeviceService is still supported for legacy applications.
Examples
The following example shows how to retrieve a list of services for all devices.
#include "stdafx.h"
#include "atlbase.h"
#include "portabledeviceapi.h"
#include "portabledevice.h"
HRESULT GetServiceName( LPCWSTR pszPnpServiceID, LPWSTR* ppszServiceName);
HRESULT EnumerateServicesForDevice(
IPortableDeviceServiceManager* pPortableDeviceServiceManager,
LPCWSTR pszPnpDeviceID);
int _tmain(int argc, _TCHAR* argv[])
{
HRESULT hr = S_OK;
DWORD cPnPDeviceIDs = 0;
LPWSTR* pPnpDeviceIDs = NULL;
CComPtr<IPortableDeviceManager> pPortableDeviceManager;
CComPtr<IPortableDeviceServiceManager> pPortableDeviceServiceManager;
// Initialize COM for COINIT_MULTITHREADED
hr = CoInitializeEx(NULL, COINIT_MULTITHREADED);
// CoCreate the IPortableDeviceManager interface to enumerate
// portable devices and to get information about them.
if (hr == S_OK)
{
hr = CoCreateInstance(CLSID_PortableDeviceManager,
NULL,
CLSCTX_INPROC_SERVER,
IID_IPortableDeviceManager,
(VOID**) &pPortableDeviceManager);
}
if (hr == S_OK)
{
// Get the PortableDeviceServiceManager interface
// by calling QueryInterface from IPortableDeviceManager
hr = pPortableDeviceManager->QueryInterface
(IID_IPortableDeviceServiceManager,
(VOID**) &pPortableDeviceServiceManager);
}
// Get the number of devices on the system
if (hr == S_OK)
{
hr = pPortableDeviceManager->GetDevices(NULL, &cPnPDeviceIDs);
}
// If we have at least 1 device,
// continue to query the list of services for each device
if ((hr == S_OK) && (cPnPDeviceIDs > 0))
{
pPnpDeviceIDs = new LPWSTR[cPnPDeviceIDs];
if (pPnpDeviceIDs != NULL)
{
hr = pPortableDeviceManager->GetDevices
(pPnpDeviceIDs, &cPnPDeviceIDs);
if (SUCCEEDED(hr))
{
for (DWORD dwIndex = 0; dwIndex < cPnPDeviceIDs; dwIndex++)
{
hr = EnumerateServicesForDevice
(pPortableDeviceServiceManager, pPnpDeviceIDs[dwIndex]);
}
}
// Free all returned PnPDeviceID strings
FreePortableDevicePnPIDs(pPnpDeviceIDs, cPnPDeviceIDs);
// Delete the array of LPWSTR pointers
delete [] pPnpDeviceIDs;
pPnpDeviceIDs = NULL;
}
}
return 0;
}
HRESULT EnumerateServicesForDevice(
IPortableDeviceServiceManager* pPortableDeviceServiceManager,
LPCWSTR pszPnpDeviceID)
{
HRESULT hr = S_OK;
DWORD cPnpServiceIDs = 0;
LPWSTR* pPnpServiceIDs = NULL;
if (pPortableDeviceServiceManager == NULL)
{
return E_POINTER;
}
// Get the number of services for the device
if (hr == S_OK)
{
hr = pPortableDeviceServiceManager->GetDeviceServices(
pszPnpDeviceID,
GUID_DEVINTERFACE_WPD_SERVICE, NULL, &cPnpServiceIDs);
}
// If we have at least 1, continue to gather information about
// each service and populate the device information array.
if ((hr == S_OK) && (cPnpServiceIDs > 0))
{
pPnpServiceIDs = new LPWSTR[cPnpServiceIDs];
if (pPnpServiceIDs != NULL)
{
// Get a list of all services on the given device.
// To query a give type of service (e.g. the Contacts Service),
// a service GUID can be provided here instead of
// GUID_DEVINTERFACE_WPD_SERVICE which returns all services
DWORD dwIndex = 0;
hr = pPortableDeviceServiceManager->GetDeviceServices
(pszPnpDeviceID, GUID_DEVINTERFACE_WPD_SERVICE,
pPnpServiceIDs, &cPnpServiceIDs);
if (SUCCEEDED(hr))
{
// For each service found, read the name property
for (dwIndex = 0; dwIndex < cPnpServiceIDs && SUCCEEDED(hr);
dwIndex++)
{
LPWSTR pszServiceName = NULL;
hr = GetServiceName(pPnpServiceIDs[dwIndex],
&pszServiceName);
CoTaskMemFree(pszServiceName);
}
}
FreePortableDevicePnPIDs(pPnpServiceIDs, cPnpServiceIDs);
// Delete the array of LPWSTR pointers
delete [] pPnpServiceIDs;
pPnpServiceIDs = NULL;
}
}
}
HRESULT GetServiceName( LPCWSTR pszPnpServiceID,
LPWSTR* ppszServiceName)
{
HRESULT hr = S_OK;
LPWSTR pszServiceID = NULL;
LPWSTR pszServiceObjectID = NULL;
CComPtr<IPortableDeviceValues> pClientInfo;
CComPtr<IPortableDeviceValues> pPropertyValues;
CComPtr<IPortableDeviceService> pService;
CComPtr<IPortableDeviceContent2> pContent;
CComPtr<IPortableDeviceProperties>pProperties;
CComPtr<IPortableDeviceKeyCollection> pPropertiesToRead;
hr = CoCreateInstance(CLSID_PortableDeviceServiceFTM,
NULL,
CLSCTX_INPROC_SERVER,
IID_IPortableDeviceService,
(VOID**) &pService);
if (hr == S_OK)
{
// CoCreate an IPortableDeviceValues interface
// to hold the client information.
hr = CoCreateInstance(CLSID_PortableDeviceValues,
NULL,
CLSCTX_INPROC_SERVER,
IID_IPortableDeviceValues,
(VOID**) & pClientInfo);
if ((hr == S_OK) && (pClientInfo!= NULL))
{
hr = pClientInfo->SetStringValue
(WPD_CLIENT_NAME, L"Service Sample Application");
if (hr == S_OK)
{
hr = pClientInfo->SetUnsignedIntegerValue(
WPD_CLIENT_MAJOR_VERSION, 1);
}
if (hr == S_OK)
{
hr = pClientInfo->SetUnsignedIntegerValue(
WPD_CLIENT_MINOR_VERSION, 0);
}
if (hr == S_OK)
{
hr = pClientInfo->SetUnsignedIntegerValue(
WPD_CLIENT_REVISION, 0);
}
if (hr == S_OK)
{
hr = pClientInfo->SetUnsignedIntegerValue(
WPD_CLIENT_SECURITY_QUALITY_OF_SERVICE,
SECURITY_IMPERSONATION);
}
if (hr == S_OK)
{
// Open a connection to the service
hr = pService->Open(pszPnpServiceID,
pClientInfo);
}
if (hr == S_OK)
{
hr = pService->GetServiceObjectID(&pszServiceID);
}
if (hr == S_OK)
{
hr = pService->Content(&pContent);
}
if (hr == S_OK)
{
hr = pContent->Properties(&pProperties);
}
// Create a IPortableDeviceKeyCollection
// containing the single PROPERTYKEY
if (hr == S_OK)
{
hr = CoCreateInstance(CLSID_PortableDeviceKeyCollection,
NULL,
CLSCTX_INPROC_SERVER,
IID_IPortableDeviceKeyCollection,
(VOID**) &pPropertiesToRead);
}
// Add our property key
if (hr == S_OK)
{
hr = pPropertiesToRead->Add(WPD_OBJECT_NAME);
}
if (hr == S_OK)
{
hr = pProperties->GetValues(
pszServiceID,
pPropertiesToRead, &pPropertyValues);
}
if (hr == S_OK)
{
hr = pPropertyValues->GetStringValue(
WPD_OBJECT_NAME, ppszServiceName);
}
CoTaskMemFree(pszServiceObjectID);
return hr;
}
}
}
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 7 [desktop apps | UWP apps] |
| Minimum supported server | None supported |
| Target Platform | Windows |
| Header | portabledeviceapi.h |
See also