/// <summary>
/// Called on a new thread to process events from the graph. The thread
/// exits when the graph finishes. Cancelling is done here.
/// </summary>
private void EventWait()
{
try
{
// Returned when GetEvent is called but there are no events
const int E_ABORT = unchecked ((int)0x80004004);
int hr;
IntPtr p1, p2;
EventCode ec;
// TODO: present the event code in the OnCompleted event
EventCode exitCode;
var pEvent = (IMediaEvent)Graph;
do
{
// Read the event
for (
hr = pEvent.GetEvent(out ec, out p1, out p2, 100);
hr >= 0 && _state < RendererState.GraphCompleted;
hr = pEvent.GetEvent(out ec, out p1, out p2, 100)
)
{
switch (ec)
{
// If the clip is finished playing
case EventCode.Complete:
case EventCode.ErrorAbort:
ChangeState(RendererState.GraphStarted, RendererState.GraphCompleting);
exitCode = ec;
// Release any resources the message allocated
hr = pEvent.FreeEventParams(ec, p1, p2);
DESError.ThrowExceptionForHR(hr);
break;
default:
// Release any resources the message allocated
hr = pEvent.FreeEventParams(ec, p1, p2);
DESError.ThrowExceptionForHR(hr);
break;
}
}
// If the error that exited the loop wasn't due to running out of events
if (hr != E_ABORT)
{
DESError.ThrowExceptionForHR(hr);
}
} while (_state < RendererState.GraphCompleting);
// If the user canceled
if (_state == RendererState.Cancelling)
{
// Stop the graph, send an appropriate exit code
hr = _mediaControl.Stop();
exitCode = EventCode.UserAbort;
}
if (_state == RendererState.GraphCompleting)
{
ChangeState(RendererState.GraphCompleted);
OnRenderCompleted();
if (_renderResult != null)
{
_renderResult.Complete(false);
}
if (_cancelResult != null)
{
_cancelResult.Complete(false);
}
}
else
{
ChangeState(RendererState.Canceled);
OnRenderCompleted();
if (_renderResult != null)
{
_renderResult.Complete(true);
}
if (_cancelResult != null)
{
_cancelResult.Complete(false);
}
}
}
catch (COMException ex)
{
if (_renderResult != null)
{
_renderResult.Complete(ex);
}
if (_cancelResult != null)
{
_cancelResult.Complete(ex);
}
}
}
