使用 Thread.sleep 让 UI 线程等待

我用 C# 为 WP7 编写了这段代码：

public void btn_handler(object sender, EventArgs args)
    {
        Button btn_Pressed = (Button)sender;
        ImageBrush br = new ImageBrush();
        br.ImageSource = new BitmapImage(new Uri("/images/cat.png"
                                                 , UriKind.Relative));

        btn_Pressed.Background = br;

        Thread.Sleep(5000);

       SolidColorBrush sBrush = new SolidColorBrush(); 
       sBrush.Color = System.Windows.Media.Colors.White;
       btn_Pressed.Background = sBrush;            
    }

每当用户单击按钮时，我希望按钮的背景更改为图像。大约 5 秒后，我希望背景变回白色。目前，程序不会改变按钮的背景图片，而是等待5秒，直接将背景改为白色。

我是 WP 的菜鸟。我尝试寻找解决方案，得到的是创建一个调度程序线程，但我不明白如何继续。请帮忙 ：（

您当前的方法是不正确的。它让 UI 线程变得忙碌。它会在空闲时更新 UI。

这是正在发生的事情

按钮获得点击。 UI 线程将按钮背景更改为图像。然后它会休眠 5 秒，然后将背景更改为白色。请注意，UI 线程仍然繁忙。它只会在免费时更新实际的 UI。一旦它将背景颜色更改为白色，它就会释放并更新 UI，您会在屏幕上看到更改。

你需要这样做

 //inside the button click event create a background worker
 BackgroundWorker worker = new BackgroundWorker();
 worker.RunWorkerCompleted += new 

 RunWorkerCompletedEventHandler(worker_RunWorkerCompleted);
 worker.DoWork += new DoWorkEventHandler(worker_DoWork);
 worker.RunWorkerAsync();

 Button btn_Pressed = (Button)sender;
 ImageBrush br = new ImageBrush();
 br.ImageSource = new BitmapImage(new Uri("/images/cat.png", UriKind.Relative));

 btn_Pressed.Background = br;


 public static void worker_RunWorkerCompleted(object sender, 
                                              RunWorkerCompletedEventArgs e)
    {
    //once backgroudn work i.e. DoWork is complete this method will be 
    //called and code below will execute in UI thread
    SolidColorBrush sBrush = new SolidColorBrush(); 
    sBrush.Color = System.Windows.Media.Colors.White;
    btn_Pressed.Background = sBrush;  
    }

 public  static  void worker_DoWork(object sender, DoWorkEventArgs e)
    {
    //it will wait 5 secs in the background thread
    Thread.Sleep(5000);
    }