IAMOpenProgress interface reports the progress of a file-open operation and enables 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.
The IAMOpenProgress interface has these methods.
|IAMOpenProgress::AbortOperation||The AbortOperation method cancels the file-open operation.|
|IAMOpenProgress::QueryProgress||The QueryProgress method retrieves the progress of the file-open operation.|
|Minimum supported client||Windows 2000 Professional [desktop apps only]|
|Minimum supported server||Windows 2000 Server [desktop apps only]|
|Header||strmif.h (include Dshow.h)|