Microsoft DirectX 8.0 |
Reports the progress of a file-open 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 abort 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 abort the operation if a predefined timeout occurs, or in response to a command from the user.
The URL File Source filter supports this interface.
IUnknown methods Description QueryInterface Retrieves pointers to supported interfaces. AddRef Increments the reference count. Release Decrements the reference count. IAMOpenProgress methods Description QueryProgress Retrieves the progress of the file-open operation. AbortOperation Aborts the file-open operation.
Aborts the file-open operation.
Syntax
HRESULT AbortOperation(void);
Return Value
Returns S_OK if successful, or an HRESULT value indicating the cause of the error.
Retrieves the progress of the file-open operation.
Syntax
HRESULT QueryProgress( LONGLONG *pllTotal, LONGLONG *pllCurrent );
Parameters
- pllTotal
- [out] Pointer to a variable that receives the length of the entire file, in bytes.
- pllCurrent
- [out] Pointer to a variable that receives the length of the downloaded portion of the file, in bytes.
Return Value
Returns an HRESULT value. Possible values include those shown in the following table.
S_OK Success. VFW_S_ESTIMATED The returned values are estimates. E_UNEXPECTED Unexpected error.