为什么在不同的线程中创建窗口时,有时会出现“无效的窗口句柄”异常

时间:2014-01-17 05:04:48

标签: c# wpf multithreading

根据以下代码创建Invalid window handle时,我收到“Window”异常。这是在一个单独的线程上调用的。它不是每次都抛出,而是随机发生的。此外,我无法查看异常的堆栈跟踪,并显示“{Unable to evaluate expression because the code is optimized or a native frame is on top of the call stack.}

private void ShowDialog()
{
    Thread thread = new Thread(() =>
        {
            waitContainer = MakeSimpleWindow();
            this.waitContainer.Closed += new EventHandler(waitingWindow_Closed);

            waitContainer.ShowDialog();

            System.Windows.Threading.Dispatcher.Run();
        });
        thread.SetApartmentState(ApartmentState.STA);
        thread.IsBackground = true;
        thread.Start();
}

public Window MakeSimpleWindow()
    {
        Window w = new Window(); // Exception occurs from here
        w.Title = Attributes[MessageBoxAttribute.message];            
        return w;
    }

1 个答案:

答案 0 :(得分:5)

2行:

waitContainer.ShowDialog();\    
System.Windows.Threading.Dispatcher.Run();

至少有竞争条件。当ShowDialog开始执行时,Thread尚未运行Dispatcher。

但答案不是如何解决这个问题。虽然你可以执行更多的1个调度程序,但它很少是个好主意。寻找一个运行1个GUI线程(主线程)的解决方案,并解决Invoke和事件的其他问题。