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The CMediaControlclass provides base class handling of the IDispatchmethods of the dual-interface IMediaControl. It leaves as pure virtual the properties and methods of the IMediaControlinterface.
Typically, the filter graph manager is the only object that implements the IMediaControlinterface. (Filters implement the IMediaFilterinterface, inherited by IBaseFilter, to receive control commands from the filter graph manager.) Therefore, this class library is of limited use to filter developers.
The CMediaControl::GetIDsOfNames, CMediaControl::GetTypeInfo, CMediaControl::GetTypeInfoCount, and CMediaControl::Invokemember functions are standard implementations of the IDispatchmethods using the CBaseDispatchclass (and a type library) to parse the commands and pass them to the pure virtual methods of the IMediaControlinterface.
The IMediaControlmethods, defined in control.odl, are left as pure virtual.
Member Functions
| CMediaControl | Constructs a CMediaControlobject. |
Implemented INonDelegatingUnknown Methods
| NonDelegatingQueryInterface | Returns a specified reference-counted interface. |
Implemented IDispatch Methods
| GetIDsOfNames | Maps a single member and an optional set of parameters to a corresponding set of integer dispatch identifiers (DISPIDs), which can be used during subsequent calls to the CMediaControl::Invokemethod. |
| GetTypeInfo | Retrieves a type-information object, which can retrieve the type information for an interface. |
| GetTypeInfoCount | Retrieves the number of type-information interfaces provided by an object. |
| Invoke | Provides access to properties and methods exposed by an object. |