|Microsoft DirectX 9.0|
The IAMOpenProgress interface provides methods that report the progress of a file-open operation and enable the application to cancel the operation.
Filters that open files over a network can expose this interface. An application can use it to query the progress of the download, or to cancel the download. If the network is not responsive, a method such as IGraphBuilder::RenderFile might block for an indefinite period. To prevent your application from blocking, create a worker thread that uses IAMOpenProgress to monitor the progress. The worker thread can cancel the operation if a predefined timeout occurs, or in response to a command from the user.
The File Source (URL) filter supports this interface.
In addition to the methods inherited from IUnknown, the IAMOpenProgress interface exposes the following methods.
|QueryProgress||Retrieves the progress of the file-open operation.|
|AbortOperation||Cancels the file-open operation.|