c# – 从委托中锁定静态对象不起作用

private static object Lock_HandleError = new object();
public static void HandleError(Exception ex)
{
    lock( Lock_HandleError )
    {
        //IF the UI is processing a visual tree event (such as IsVisibleChanged),it throws an exception when showing a MessageBox as described here: http://social.msdn.microsoft.com/forums/en-US/wpf/thread/44962927-006e-4629-9aa3-100357861442
        //The solution is to dispatch and queue the MessageBox. We must use BeginInvoke because dispatcher processing is suspended in such cases.
        Dispatcher.CurrentDispatcher.BeginInvoke((Action)delegate()
        {
            lock( Lock_HandleError )
            {
                Dispatcher.CurrentDispatcher.BeginInvoke((Action)delegate(){ 
                    HandleError(new Exception("testing purposes only")); 
                },DispatcherPriority.Background);

                MessageBox.Show(ex.Message,"Application Error",MessageBoxButton.OK,MessageBoxImage.Error);
                //This point is not reached until the user clicks "OK"
            }
        },DispatcherPriority.Background);
    }
}

public void main()
{
    HandleError(new Exception("The first error"));
}

上述代码的预期行为是一次出现一条错误消息,当用户单击“确定”时,Lock_HandleError对象将从调度的线程释放,下一次调用HandleError可以继续 – 但是我得到的是无限级联的错误消息,而没有达到“OK”.

为什么这个锁没有工作？

通过在每个lock语句的入口和出口处设置断点,我可以清楚地看到委托正在调用lock()并再次调用新的“HandleError”调用,然后在MessageBox上暂停以等待用户输入.

同时,在另一个线程中,对HandleError的调度调用会运行 – 但不是像它应该那样等待lock()语句,它只是爆破它,即使MessageBox委托显然放置了一个锁并且还没有释放它.