Microsoft DirectX 8.0 |
Enables an application to cancel or modify graph-control commands that the application previously queued using the IQueueCommand interface.
When an application calls an IQueueCommand method on the filter graph manager, it receives a pointer to the IDeferredCommand interface. The application can use the interface to cancel or postpone the command, or retrieve the return value from the command.
Methods in Vtable Order
IUnknown methods Description QueryInterface Retrieves pointers to supported interfaces. AddRef Increments the reference count. Release Decrements the reference count. IDeferredCommand methods Description Cancel Cancels a command that the application previously queued. Confidence Retrieves a confidence value that indicates how likely it is for the command to be invoked at the requested time. Postpone Specifies a new invocation time for the command. GetHResult Retrieves the return value from the invoked command.
Cancels a command that the application previously queued.
Syntax
HRESULT Cancel(void);
Return Value
Returns S_OK if successful. If the request was already canceled, returns VFW_E_ALREADY_CANCELLED.
Retrieves a confidence value that indicates how likely it is for the command to be invoked at the requested time.
This method is not implemented and returns E_NOTIMPL.
Syntax
HRESULT Confidence( LONG *pConfidence );
Parameters
- pConfidence
- Pointer to a variable that receives the confidence level, on a scale of 0 to 100.
Return Value
Returns E_NOTIMPL.
Retrieves the return value from the invoked command.
Syntax
HRESULT GetHResult( HRESULT *phrResult );
Parameters
- phrResult
- Pointer to a variable that receives the HRESULT value.
Return Value
Returns an HRESULT value. Possible values include the following.
S_OK Success. E_ABORT Command has not yet been invoked. E_POINTER NULL pointer argument.
Specifies a new invocation time for the command.
Syntax
HRESULT Postpone( REFTIME newtime );
Parameters
- newtime
- New time at which to invoke the command.
Return Value
Returns S_OK if successful. If the requested time has already passed, returns VFW_E_TIME_ALREADY_PASSED.