Question

我正在尝试创建一个计时器，返回我的WPF应用程序的主菜单，比方说，30秒不活动。但我收到错误“调用线程无法访问此对象，因为另一个线程拥有它。”它发生在FadeOut() storyboard.Begin(uc);

我看过一些涉及调度调度程序的解决方案，但我不确定如何在我的情况下申请？

public void ResetScreen()
{
    if (!mainScreen)
    {
        Timer myTimer = new Timer();
        myTimer.Elapsed += new ElapsedEventHandler(OnTimedEvent);
        myTimer.Interval = 1000;
        myTimer.Start();
    }
}

private void OnTimedEvent(object source, ElapsedEventArgs e)
{
    TransitionContent(oldScreen, newScreen);
}

private void FadeIn(FrameworkElement uc)
{
    DoubleAnimation dAnimation = new DoubleAnimation();
    dAnimation.Duration = new Duration(TimeSpan.FromSeconds(1.0));
    dAnimation.From = 0;
    dAnimation.To = 1;
    Storyboard.SetTarget(dAnimation, uc);
    Storyboard.SetTargetProperty(dAnimation, new PropertyPath(OpacityProperty));
    Storyboard storyboard = new Storyboard();
    storyboard.Children.Add(dAnimation);
    storyboard.Begin(uc);
}

private void FadeOut(FrameworkElement uc)
{
    DoubleAnimation dAnimation = new DoubleAnimation();
    dAnimation.Duration = new Duration(TimeSpan.FromSeconds(1.0));
    dAnimation.From = 1;
    dAnimation.To = 0;
    Storyboard.SetTarget(dAnimation, uc);
    Storyboard.SetTargetProperty(dAnimation, new PropertyPath(OpacityProperty));
    Storyboard storyboard = new Storyboard();
    storyboard.Children.Add(dAnimation);
    storyboard.Begin(uc);
}

private void TransitionContent(FrameworkElement oldScreen, FrameworkElement newScreen)
{
    FadeOut(oldScreen);
    FadeIn(newScreen);
}

Answer 1

这个可能是一个解决方案：

this.Dispatcher.Invoke((Action)(()=>{
      // In here, try to call the stuff which making some changes on the UI
});

如：

private void TransitionContent(FrameworkElement oldScreen, FrameworkElement newScreen)
{
     this.Dispatcher.Invoke((Action)(()=>{
          FadeOut(oldScreen);
          FadeIn(newScreen);   
     });
}

Answer 2

您的问题是System.Timers.Timer事件在与UI线程不同的线程上运行。您可以尝试直接调用其他人提到的内容，也可以使用DispatcherTimer。

调用线程无法访问此对象

2 个答案: