Question

WPF 如何给动画加速

我定义了一个动画，就是一个圈一直按照一定速度转。然后每过一秒将圈的速度加快。（通过speedRatio加速）

我在实现的时候发现如果直接stop和begin的话每次加速动画会重置，而我希望每次圈加速后都是从当前旋转的角度开始，而不是从0°开始，请问有什么办法么？？

有没有办法获取solarGrid1.RenderTransform里面的angle的值呢？？

RotateTransform rt = new RotateTransform();
solarGrid1.RenderTransform = rt;

backgroundEllipseDoubleAnimation = new DoubleAnimation();
backgroundEllipseDoubleAnimation.From = 0;
backgroundEllipseDoubleAnimation.To = 360;
backgroundEllipseDoubleAnimation.Duration = new Duration(TimeSpan.FromMilliseconds(1500));
backgroundEllipseDoubleAnimation.RepeatBehavior = RepeatBehavior.Forever;

backgroundStoryboard = new Storyboard();
backgroundStoryboard.Children.Add(backgroundEllipseDoubleAnimation);
Storyboard.SetTarget(backgroundEllipseDoubleAnimation, solarGrid1);
Storyboard.SetTargetProperty(backgroundEllipseDoubleAnimation, new PropertyPath("RenderTransform.Angle"));
//backgroundStoryboard.CurrentTimeInvalidated +=
// new EventHandler(Invalidated);
backgroundStoryboard.Begin();

Answer 1

<Button RenderTransformOrigin="0.5,0.5">
            <Button.RenderTransform>
                <TransformGroup>
                    <RotateTransform x:Name="myAngle" Angle="29.587"/>
                </TransformGroup>
            </Button.RenderTransform>
</Button>

为RotateTransform 起个名字，通过

myAngle.Angle 应该能得到你要的值