public static void PushFrame(DispatcherFrame frame)
{
if (frame == null)
{
throw new ArgumentNullException();
}
Dispatcher currentDispatcher = Dispatcher.CurrentDispatcher;
if (currentDispatcher._hasShutdownFinished)
{
throw new InvalidOperationException();
}
currentDispatcher.PushFrameImpl(frame);
}
//
// instance implementation of PushFrame
private void PushFrameImpl(DispatcherFrame frame)
{
var prevFrame = this._currentFrame;
this._frameDepth++;
try {
this._currentFrame = frame;
while (frame.Continue)
{
DispatcherOperation op = null;
var aborted = false;
//
// Dequeue the next operation if appropriate
if (this._queue.Count > 0)
{
op = (DispatcherOperation)this._queue.Dequeue();
//Must check aborted flag inside lock because
//user program could call op.Abort() between
//here and before the call to Invoke()
aborted = op.Status == DispatcherOperationStatus.Aborted;
}
if (op != null)
{
if (!aborted)
{
// Invoke the operation:
Debug.Assert(op._status == DispatcherOperationStatus.Pending);
// Mark this operation as executing.
op._status = DispatcherOperationStatus.Executing;
op._result = null;
try {
op._result = op._method(op._args);
}
catch (Exception e) {
if (this._finalExceptionHandler == null ||
!this._finalExceptionHandler(op, e))
{
throw;
}
}
// Mark this operation as completed.
op._status = DispatcherOperationStatus.Completed;
// Raise the Completed so anyone who is waiting will wake up.
op.OnCompleted();
}
}
else
{
this._event.WaitOne();
}
}
}
finally {
this._frameDepth--;
this._currentFrame = prevFrame;
// If this was the last frame to exit after a quit, we
// can now dispose the dispatcher.
if (this._frameDepth == 0)
{
if (this._hasShutdownStarted)
{
ShutdownImpl();
}
}
}
}