|Microsoft DirectX 9.0|
The Block method blocks or unblocks the flow of data from the pin.
HRESULT Block( DWORD dwBlockFlags, HANDLE hEvent );
[in] Flag that indicates whether to block or unblock the pin. Must be one of the following values:
[in] Handle to an event object, or NULL. If this parameter is non-NULL, the method is asynchronous and returns immediately. The event is signaled when the operation completes. If this parameter is NULL, the method is synchronous and does not complete until the pin is blocked. If dwBlockFlags is zero, this parameter must be NULL.
Returns an HRESULT value. Possible values include the following.
|S_FALSE||Pin is already unblocked.|
|VFW_E_PIN_ALREADY_BLOCKED||Pin is already blocked on another thread.|
|VFW_E_PIN_ALREADY_BLOCKED_ON_THIS_THREAD||Pin is already blocked on the calling thread.|
This method can be synchronous or asynchronous: