IMediaEventEx Interface
This interface derives from IMediaEvent and adds a method that allows registration of a window to receive messages when events occur.
When to Implement
This interface is implemented by the filter graph manager.
Unlike IMediaEvent, IMediaEventEx is not available through Automation, and therefore cannot be called directly from Microsoft® Visual Basic®.
The CMediaEvent Class supports IMediaEventEx.
When to Use
This interface is used by applications 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 DirectShow Event Notification Codes.
Methods in Vtable Order
The following tables show the methods that appear in the Vtable beneath the standard COM methods inherited from IUnknown.
| IDispatch method | Description |
|---|---|
| GetTypeInfoCount | Determines whether there is type information available for this dispinterface. |
| GetTypeInfo | Retrieves the type information for this dispinterface if GetTypeInfoCount returned successfully. |
| GetIDsOfNames | Converts text names of properties and methods (including arguments) to their corresponding DISPIDs. |
| Invoke | Calls a method or accesses a property in this dispinterface if given a DISPID and any other necessary parameters. |
| IMediaEvent method | Description |
|---|---|
| GetEventHandle | Retrieves a handle to a manual-reset event that will be signaled. |
| GetEvent | Retrieves the next notification event. |
| WaitForCompletion | Waits until the graph's operation has completed. |
| CancelDefaultHandling | Cancels any default handling of the specified event by the filter graph. |
| RestoreDefaultHandling | Restores default handling for this event. |
| FreeEventParams | Frees resources associated with the parameters to an event. |
| IMediaEventEx method | Description |
|---|---|
| SetNotifyWindow | Registers a window that will handle messages when a specified event occurs. |
| SetNotifyFlags | Turns event notifications on or off. |
| GetNotifyFlags | Retrieves whether event notifications are on or off. |
Requirements
DirectShow applications and DirectShow filters have different include file and link library requirements. See Setting Up the Build Environment for more information.
OS Versions: Windows CE 2.12 and later. Version 2.12 requires DXPAK 1.0 or later.
See Also
Last updated on Wednesday, April 13, 2005
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