c# - 在 WPF 中的代码中创建闪烁动画

Question

我想将Blink动画应用于 a ，Canvas以便我在其上绘制的所有对象都会随之闪烁。

我使用下面的代码已经取得了一定的成功，它改变了相当快的Opacity属性Canvas来实现这个效果，但我对它有点不满意。

我更喜欢FadeOut/FadeIn像我当前的代码那样没有任何东西的纯粹眨眼。我怎样才能以正确的方式做到这一点？

var blinkAnimation = new DoubleAnimation
{
    From = 1,
    To = 0
};

var blinkStoryboard = new Storyboard
{
    Duration = TimeSpan.FromMilliseconds(500),
    RepeatBehavior = RepeatBehavior.Forever,
    AutoReverse = true
};

Storyboard.SetTarget(blinkAnimation, MyCanvas);
Storyboard.SetTargetProperty(blinkAnimation, new PropertyPath(OpacityProperty));

blinkStoryboard.Children.Add(blinkAnimation);
MyCanvas.BeginStoryboard(blinkStoryboard);

也许我可以使用 来做到这一点，VisibilityProperty但我做错了。

Answer 1

您可以使用带有适当的第二个动画BeginTime：

var switchOffAnimation = new DoubleAnimation
{
    To = 0,
    Duration = TimeSpan.Zero
};

var switchOnAnimation = new DoubleAnimation
{
    To = 1,
    Duration = TimeSpan.Zero,
    BeginTime = TimeSpan.FromSeconds(0.5)
};

var blinkStoryboard = new Storyboard
{
    Duration = TimeSpan.FromSeconds(1),
    RepeatBehavior = RepeatBehavior.Forever
};

Storyboard.SetTarget(switchOffAnimation, MyCanvas);
Storyboard.SetTargetProperty(switchOffAnimation, new PropertyPath(Canvas.OpacityProperty));
blinkStoryboard.Children.Add(switchOffAnimation);

Storyboard.SetTarget(switchOnAnimation, MyCanvas);
Storyboard.SetTargetProperty(switchOnAnimation, new PropertyPath(Canvas.OpacityProperty));
blinkStoryboard.Children.Add(switchOnAnimation);

MyCanvas.BeginStoryboard(blinkStoryboard);

Answer 2

如果您想要动画的开/关状态，您可以将动画更改为DoubleAnimationUsingKeyFrames

var blinkAnimation = new DoubleAnimationUsingKeyFrames();
blinkAnimation.KeyFrames.Add(new DiscreteDoubleKeyFrame(1, KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(0))));
blinkAnimation.KeyFrames.Add(new DiscreteDoubleKeyFrame(0, KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(250))));

var blinkStoryboard = new Storyboard
{
    Duration = TimeSpan.FromMilliseconds(500),
    RepeatBehavior = RepeatBehavior.Forever,
};

Storyboard.SetTarget(blinkAnimation, MyCanvas);
Storyboard.SetTargetProperty(blinkAnimation, new PropertyPath(OpacityProperty));

blinkStoryboard.Children.Add(blinkAnimation);
blinkStoryboard.Begin();