如何在Silverlight中设置zIndex属性的动画？

Question

Doubleanimation does not work, because the typ is an integer. Are there any Integeranimation class? Or doing it in a different manner. I'm not interested in static animations, but event-driven (preferably programmatic) animations.

public static void Swap(UIElement ui1, UIElement ui2, double seconds)
        {
            var z2 = (int)ui1.GetValue(Canvas.ZIndexProperty);
            var z3 = (int)ui2.GetValue(Canvas.ZIndexProperty);
            DoubleAnimation da1 = new DoubleAnimation(); 
            DoubleAnimation da2 = new DoubleAnimation();
            Duration d = new Duration(TimeSpan.FromSeconds(seconds));
            da1.Duration = d;
            da2.Duration = d;
            Storyboard sb = new Storyboard();
            Storyboard.SetTarget(da1, ui1);
            Storyboard.SetTarget(da2, ui2);
            Storyboard.SetTargetProperty(da1, new PropertyPath("(Canvas.ZIndex)"));
            Storyboard.SetTargetProperty(da2, new PropertyPath("(Canvas.ZIndex)"));
            sb.Duration = d;
            sb.Children.Add(da1);
            sb.Children.Add(da2);
            da1.To = (double)z3;
            da2.To = (double)z2;
            sb.Begin();



        }

        private void Btn1_Click_1(object sender, RoutedEventArgs e)
        {
            var z2 = (int)Image2.GetValue(Canvas.ZIndexProperty);
            var z3 = (int)Image3.GetValue(Canvas.ZIndexProperty);

            Swap(Image2, Image3, 3); 

        }

Answer 1

You can animate discreet values using ObjectAnimationUsingKeyFrames with DiscreteObjectKeyFrame.

<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(Canvas.ZIndex)" Storyboard.TargetName="MyObject">
   <DiscreteObjectKeyFrame KeyTime="0" Value="250"/>
</ObjectAnimationUsingKeyFrames>

or you can do it in code.

Answer 2

You can't animate an int property. Think about what it would actually mean.

What might come close (visually) is animating the Opacity. And maybe change a Zindex at an animation-complete event.