难以使 DoubleAnimationUsingKeyFrames 工作

Difficulty in getting DoubleAnimationUsingKeyFrames to work

我正在尝试将此故事板 xaml 标记转换为 vb 代码。但是,当我 运行 代码没有任何反应时,没有引发异常或没有错误。我有什么遗漏吗?

当 运行 从 xaml 时,情节提要按预期工作,但是在我的代码隐藏翻译过程中出了点问题。

最后我可以验证附加到故事板的目标元素确实存在。

XMAL

 <Storyboard x:Name="FlipAnimation">
        <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Projection).(PlaneProjection.RotationY)" Storyboard.TargetName="Front">
            <EasingDoubleKeyFrame KeyTime="0" Value="0"/>
            <EasingDoubleKeyFrame KeyTime="0:0:0.2" Value="90"/>
        </DoubleAnimationUsingKeyFrames>
        <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Projection).(PlaneProjection.RotationY)" Storyboard.TargetName="Back">
            <EasingDoubleKeyFrame KeyTime="0" Value="-90"/>
            <EasingDoubleKeyFrame KeyTime="0:0:0.2" Value="-90"/>
            <EasingDoubleKeyFrame KeyTime="0:0:0.4" Value="0"/>
        </DoubleAnimationUsingKeyFrames>
    </Storyboard>

代码隐藏

 Dim firstKf As DoubleAnimationUsingKeyFrames = New DoubleAnimationUsingKeyFrames
    firstKf.KeyFrames.Add(New EasingDoubleKeyFrame With {.KeyTime = TimeSpan.Zero, .Value = "0"})
    firstKf.KeyFrames.Add(New EasingDoubleKeyFrame With {.KeyTime = TimeSpan.FromMilliseconds(200), .Value = "90"})
    Media.Animation.Storyboard.SetTargetProperty(firstKf, New PropertyPath(PlaneProjection.RotationYProperty))
    Media.Animation.Storyboard.SetTarget(firstKf, front)

    Dim secondKf As DoubleAnimationUsingKeyFrames = New DoubleAnimationUsingKeyFrames
    secondKf.KeyFrames.Add(New EasingDoubleKeyFrame With {.KeyTime = TimeSpan.Zero, .Value = "-90"})
    secondKf.KeyFrames.Add(New EasingDoubleKeyFrame With {.KeyTime = TimeSpan.FromMilliseconds(200), .Value = "-90"})
    secondKf.KeyFrames.Add(New EasingDoubleKeyFrame With {.KeyTime = TimeSpan.FromMilliseconds(400), .Value = "0"})
    Media.Animation.Storyboard.SetTargetProperty(secondKf, New PropertyPath(PlaneProjection.RotationYProperty))
    Media.Animation.Storyboard.SetTarget(secondKf, back)

    Dim sb = New Media.Animation.Storyboard
    sb.Children.Add(firstKf)
    sb.Children.Add(secondKf)
    sb.Begin()

您似乎在两个动画上绑定了不正确的 属性 路径。你要

New PropertyPath("Projection.RotationY")

或者也许

New PropertyPath("(UIElement.Projection).(PlaneProjection.RotationY)")

因为 frontback 不直接包含 PlaneProjection.RotationYProperty.