/// <summary>
/// 不使用任何参数初始化 UIMessageProcessor 的新实例。
/// </summary>
public UIMessageProcessor()
{
_MessageLoopThread = new Thread(new ThreadStart(_ThreadStartMethod));
_MessageLoopThread.IsBackground = true;
_AsyncMessages = new Queue <UIMessage>();
_SyncMessages = new Queue <UIMessage>();
_Sender = null;
_StoppedCallbackMethod = null;
_State = UIMessageProcessorState.Stopped;
}
/// <summary>
/// 所有正在处理的消息处理完成后，停止在此界面消息处理器上运行消息循环。
/// </summary>
/// <param name="sender">调用此方法的控件。</param>
/// <param name="callbackMethod">回调方法。</param>
public void Stop(Control sender, UIMessageProcessorStoppedHandler callbackMethod)
{
if (sender is null || callbackMethod is null)
{
throw new ArgumentNullException();
}
if (State != UIMessageProcessorState.Running)
{
throw new InvalidOperationException();
}
//
_Sender = sender;
_StoppedCallbackMethod = callbackMethod;
State = UIMessageProcessorState.Stopping;
}
//
// 消息循环线程执行的方法。
private void _ThreadStartMethod()
{
Stopwatch sw = new Stopwatch();
while (true)
{
if (State == UIMessageProcessorState.Stopping && _GetProcessingAsyncMessageCount() <= 0)
{
break;
}
//
sw.Restart();
MessageLoop();
sw.Stop();
if (sw.ElapsedMilliseconds < 1)
{
int count = 0;
_MessageQueueLock.EnterReadLock();
try
{
count = _AsyncMessages.Count + _SyncMessages.Count;
}
finally
{
_MessageQueueLock.ExitReadLock();
}
if (count > 0)
{
Thread.Sleep(0);
}
else
{
Thread.Sleep(1);
}
}
else
{
Thread.Sleep(0);
}
}
//
_MessageQueueLock.EnterReadLock();
try
{
_AsyncMessages.Clear();
_SyncMessages.Clear();
}
finally
{
_MessageQueueLock.ExitReadLock();
}
State = UIMessageProcessorState.Stopped;
//
if (!(_Sender is null) && !(_StoppedCallbackMethod is null))
{
_Sender.Invoke(_StoppedCallbackMethod, _Sender, this);
_Sender = null;
_StoppedCallbackMethod = null;
}
}
