Question

我正在使用DispatcherTimer调用方法在不同的线程中执行。我正在运行一个简单的程序，不需要真正担心效率低下。如何让UI线程等待DispatcherTimer完成，同时仍然允许DispatcherTimer线程对UI进行更改？

*我理解这可能是半重复的，但我看到的例子都是特定于案例的。感谢

private void spinButton_Click(object sender, RoutedEventArgs e)
    {

        minSelTextBlock.Text = "";

            Index = 0;
            maxIndex = rnd.Next(40, 60);
            DispatcherTimer timer;
            timer = new DispatcherTimer(DispatcherPriority.Normal);
            timer.Interval = TimeSpan.FromMilliseconds(60);
            timer.Tick += new EventHandler(TimerTick);
            timer.Start();
            selPeople[x].IsCheck = false;
            displayCount++;

            Index = 0;
            maxIndex = rnd.Next(40, 60);
            timer = new DispatcherTimer(DispatcherPriority.Normal);
            timer.Interval = TimeSpan.FromMilliseconds(60);
            timer.Tick += new EventHandler(TimerTick);
            timer.Start();
            selPeople[x].IsCheck = false;
            displayCount++;

            displayImage2b.Source = new BitmapImage(new Uri(selPeople[0].ImgPath));          
    }

 private void TimerTick(object sender, EventArgs e)
    {
        minSelTextBlock.Text = "";

        x = rnd.Next(0, selPeople.Count);
        while (x == temp)
        {
            x = rnd.Next(0, selPeople.Count);
        }

        if (displayCount == 0)
            displayImage1a.Source = new BitmapImage(new Uri(selPeople[x].ImgPath));
        if (displayCount == 1)
            displayImage2a.Source = new BitmapImage(new Uri(selPeople[x].ImgPath));


        if (++Index >= maxIndex)
        {
            ((DispatcherTimer)sender).Stop();
        }
        Index++;
        temp = x;
    }

基本上我需要TimerTick来获取selPeople [x]之前的最终x值.IsCheck = false，因为重点是删除刚刚从列表中选择的项目。

Answer 1

如果希望调用方法等待调用方法的结果，可以使用.Net 4.5中提供的Async / Await

您可以这样做：

private async void spin()
    {

        minSelTextBlock.Text = "";

            Index = 0;
            maxIndex = rnd.Next(40, 60);
            DispatcherTimer timer;
            timer = new DispatcherTimer(DispatcherPriority.Normal);
            timer.Interval = TimeSpan.FromMilliseconds(60);
            timer.Tick += new EventHandler(StartTicker);
            timer.Start();
            selPeople[x].IsCheck = false;
            displayCount++;

            Index = 0;
            maxIndex = rnd.Next(40, 60);

            await Ticker();

            selPeople[x].IsCheck = false;
            displayCount++;

            displayImage2b.Source = new BitmapImage(new Uri(selPeople[0].ImgPath));          
    }


  Private Task<void> StartTicker()
  {
    Task.Run<void>(()=>Ticker());
  }

private void Ticker()
    {
      while(your condition is true)
      {
        minSelTextBlock.Text = "";

        x = rnd.Next(0, selPeople.Count);
        while (x == temp)
        {
            x = rnd.Next(0, selPeople.Count);
        }

        if (displayCount == 0)
            displayImage1a.Source = new BitmapImage(new Uri(selPeople[x].ImgPath));
        if (displayCount == 1)
            displayImage2a.Source = new BitmapImage(new Uri(selPeople[x].ImgPath));


        if (++Index >= maxIndex)
        {
            break;
        }
        Index++;
        temp = x;
         Thread.Sleep(60); 
      }
    }

我没有使用计时器，而是使用了While Loop和Thread.Sleep()，它与您的计时器相同。

如果你想了解async / await我真的推荐this

再见，我没有编译这段代码。所以它可能有一些语法或其他错误。

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