The IMediaEventEx interface derives from method that allows registration of a window to receive messages when events occur. This interface is implemented by the filter graph manager . Unlike IMediaEvent , IMediaEventEx is not available through Automation, and therefore cannot be called directly from Visual Basic. The CMediaEvent class supports IMediaEventEx . Applications use this interface to receive notification that an event has occurred.
Applications can then avoid using a separate thread that waits until an event is set.
For a list of system-defined event notifications , see Event Notification Codes . Methods in Vtable Order IUnknown methods Description QueryInterface Retrieves pointers to supported interfaces. AddRef Increments the reference count. Release Decrements the reference count. IDispatch methods Description GetTypeInfoCount Determines whether there is type information available for this dispinterface.