每次按下按钮“WPF动画”时，我如何重播相同的动画

Posted 2023-04-12

【中文标题】每次按下按钮“WPF动画”时，我如何重播相同的动画

【英文标题】：How can i replay the same animation every time button pressed " WPF Animmation"

【发布时间】：2016-01-16 18:15:24

【问题描述】：

如何在每次按下按钮时重播相同的动画第一次按下 btn 动画播放但 nxt 存在运行时错误

    private void Button_Click(object sender, RoutedEventArgs e)
    
        int j = 0;
        string[] names ="/Assets/1.png", "/Assets/2.png", "/Assets/3.png", "/Assets/4.png", "/Assets/5.png" ;

        var storyboard = new Storyboard
        


        ;

        var animation = new ObjectAnimationUsingKeyFrames();

        Storyboard.SetTarget(animation,img);
        Storyboard.SetTargetProperty(animation, new PropertyPath("Source"));

        storyboard.Children.Add(animation);

        for (int i=0 ; i <=4; i++)
        
           // j = j + 1;
            var keyframe = new DiscreteObjectKeyFrame
            
                KeyTime = KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(300* i)),


               Value = String.Format(names[i])

            ;

            animation.KeyFrames.Add(keyframe);

        

            Resources.Add("Storyboard", storyboard);
            // Resources.Add("Storyboard", storyboard);

            storyboard.Begin();
           // storyboard.Completed += new EventHandler(Story_Completed);


           // Thread.Sleep(1000);
            if (j==4)
            
                storyboard.Pause();

        

        

【参考方案1】：

由于您没有提供有关异常的详细信息，因此很难判断错误来自何处，但我看到至少有一件事情可能无法正常工作：

Resources.Add("Storyboard", storyboard);

这第一次会起作用，但第二次会抛出异常（因为情节提要已经添加到资源中）。

无论如何，如果您采取一些预防措施，您可以重复使用相同的故事板对象：

首先，让我们将故事板存储在一个属性中，因为它比资源更容易操作：

private Storyboard ButtonStoryboard  get; set; 

点击按钮时，我们首先检查storyboard是否存在。如果没有，我们创建它：

if (this.ButtonStoryboard == null)

    string[] names ="/Assets/1.png", "/Assets/2.png", "/Assets/3.png", "/Assets/4.png", "/Assets/5.png" ;

    var storyboard = new Storyboard();
    var animation = new ObjectAnimationUsingKeyFrames();

    Storyboard.SetTarget(animation,img);
    Storyboard.SetTargetProperty(animation, new PropertyPath("Source"));

    storyboard.Children.Add(animation);

    for (int i=0 ; i <=4; i++)
    
        var keyframe = new DiscreteObjectKeyFrame
        
            KeyTime = KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(300* i)),
           Value = String.Format(names[i])
        ;

        animation.KeyFrames.Add(keyframe);
    

    this.ButtonStoryboard = storyboard;

现在我们必须启动情节提要，如果它还没有运行（你不能启动它两次）。如果它已经在运行，我们将其停止并倒带（就像录像带一样）：

if (this.ButtonStoryboard.GetCurrentState() != ClockState.Stopped)

    this.ButtonStoryboard.Stop();
    this.ButtonStoryboard.Seek(TimeSpan.Zero);


this.ButtonStoryboard.Begin();

综合起来：

private Storyboard ButtonStoryboard  get; set; 

private void Button_Click(object sender, RoutedEventArgs e)

    if (this.ButtonStoryboard == null)
    
        string[] names ="/Assets/1.png", "/Assets/2.png", "/Assets/3.png", "/Assets/4.png", "/Assets/5.png" ;

        var storyboard = new Storyboard();
        var animation = new ObjectAnimationUsingKeyFrames();

        Storyboard.SetTarget(animation,img);
        Storyboard.SetTargetProperty(animation, new PropertyPath("Source"));

        storyboard.Children.Add(animation);

        for (int i=0 ; i <=4; i++)
        
            var keyframe = new DiscreteObjectKeyFrame
            
                KeyTime = KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(300* i)),
               Value = String.Format(names[i])
            ;

            animation.KeyFrames.Add(keyframe);
        

        this.ButtonStoryboard = storyboard;
    

    if (this.ButtonStoryboard.GetCurrentState() != ClockState.Stopped)
    
        this.ButtonStoryboard.Stop();
        this.ButtonStoryboard.Seek(TimeSpan.Zero);
    

    this.ButtonStoryboard.Begin();