小编Qui*_*P3s的帖子

对于我的应用程序,我希望能够使用Composition API为UIElement的Offset设置动画这个元素是在Xaml中预定义的,我发现这些控件的Visual层只能在触发动画后计算...

此行为导致动画仅在第二次调用时显示

我的Xaml

<StackPanel x:Name="ActionButtonsPanel" Margin="50,175,0,0" HorizontalAlignment="Left" VerticalAlignment="Top">
    <Button x:Name="CreateNewButton" Tag="&#xE160;" Content="Create New..." Style="{StaticResource IconButtonStyle}" Click="CreateNewButton_Click"/>
    <Button x:Name="OpenFileButton" Tag="&#xE838;" Content="Open File..." Style="{StaticResource IconButtonStyle}" Margin="0,10,0,0" Click="OpenFileButton_Click"/>
</StackPanel>

我的守则

private void ShowNextButtons(UIElement Item1, UIElement Item2) {
    var _compositor = ElementCompositionPreview.GetElementVisual(this).Compositor;

    var visual1 = ElementCompositionPreview.GetElementVisual(Item1);
    visual1.CenterPoint = new Vector3(0, (float) Item1.RenderSize.Height / 2F, 0);

    var animationGroup1 = _compositor.CreateAnimationGroup();

    var offset1 = visual1.Offset; //First Time: Offset = <0,0,0>

    var fadeOut = _compositor.CreateScalarKeyFrameAnimation();
    fadeOut.Target = "Opacity";
    fadeOut.Duration = TimeSpan.FromMilliseconds(1000);
    fadeOut.InsertKeyFrame(0, 1);
    fadeOut.InsertKeyFrame(1, …