IWMSDataContainer::GetInfo
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IWMSDataContainer::GetInfo
The server calls the GetInfo method to retrieve information about the data container.
Syntax
HRESULT GetInfo( DWORD dwInfoValueId, IWMSDataContainerCallback* pCallback, QWORD qwContext );
Parameters
dwInfoValueId
[in] DWORD containing a member of the WMS_DATA_CONTAINER_GETINFO_VALUES enumeration type that identifies the type of information requested. This must be one of the following values.
Value | Description |
WMS_DATA_CONTAINER_SIZE | The size, in bytes, of the data in the data container. |
WMS_DATA_CONTAINER_MAX_SUPPORTED_READ_SIZE | The maximum packet size, in bytes, of the data in the data container. |
pCallback
[in] Pointer to the IWMSDataContainerCallback interface. The plug-in calls IWMSDataContainerCallback::OnGetInfo to send the requested information to the server.
qwContext
[in] QWORD containing a value defined by the server to identify which GetInfo request the plug-in is responding to when it calls IWMSDataContainerCallback::OnGetInfo. The plug-in must pass this value back unaltered.
Return Values
If the method succeeds, the plug-in must return S_OK. To report an error, the plug-in can return any HRESULT other than S_OK. If the plug-in uses the IWMSEventLog interface to log error information directly to the Windows Event Viewer, it is recommended that it return NS_E_PLUGIN_ERROR_REPORTED. Typically, the server attempts to make plug-in error information available to the server object model, the Windows Event Viewer, and the troubleshooting list in the details pane of the Windows Media Services MMC. However, if the plug-in uses the IWMSEventLog interface to send custom error information to the Windows Event Viewer, returning NS_E_PLUGIN_ERROR_REPORTED stops the server from also logging to the event viewer. For more information about retrieving plug-in error information, see Identifying Plug-in Errors.
Example Code
HRESULT STDMETHODCALLTYPE CDataContainer::GetInfo( DWORD dwInfoValueId, IWMSDataContainerCallback *pCallback, QWORD qwContext ) { HRESULT hr = S_OK; if( WMS_DATA_CONTAINER_SIZE = dwInfoValueId ) { //TODO: Determine the amount of data in the data container. } // Send the result, qwFileSize, to the server. Ignore any errors // by specifying S_OK for the first parameter of OnGetInfo(). pCallback->OnGetInfo( S_OK, WMS_SEEKABLE_CONTAINER, qwFileSize, qwContext ); return( hr ); }
Requirements
Header: datacontainer.h.
Library: WMSServerTypeLib.dll.
Platform: Windows Server 2003, Enterprise Edition; Windows Server 2003, Datacenter Edition; Windows Server 2008.
See Also
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