如何动画化线性梯度的起始点

Question

我有一个LinearGradientBrush用作opacityymask，我想让我的动画旋转渐变，所以我试图动画的起点和终点的位置，但我不能使它工作几个小时:

    <Style x:Key="NewContentStyle" TargetType="ContentPresenter">
        <Setter Property="OpacityMask">
            <Setter.Value>
                <LinearGradientBrush x:Name="FillGradient"  EndPoint="0.5,1" StartPoint="0.5,0">
                    <GradientStop Color="Black" Offset="0.5"/>
                    <GradientStop Color="Transparent" Offset="1"/>
                </LinearGradientBrush>
            </Setter.Value>
        </Setter>
    </Style>
    <Storyboard x:Key="NewContentStoryboard">
        <PointAnimation Storyboard.TargetProperty="StartPoint" Storyboard.TargetName="FillGradient" From="0.5 0" To="0 0.5" Duration="00:00:1" />
        <PointAnimation Storyboard.TargetProperty="EndPoint" Storyboard.TargetName="FillGradient" From="1 0.5" To="0 0.5" Duration="00:00:1"/>
    </Storyboard>

我得到一个错误"'FillGradient'的名字不能在'System.Windows.Controls.ContentPresenter'的名字范围中找到。"

Answer 1

请试试:

<Storyboard x:Key="NewContentStoryboard">
    <PointAnimation Storyboard.TargetProperty="OpacityMask.(LinearGradientBrush.StartPoint)" From="0.5 0" To="0 0.5" Duration="00:00:1" />
    <PointAnimation Storyboard.TargetProperty="OpacityMask.(LinearGradientBrush.EndPoint)" From="1 0.5" To="0 0.5" Duration="00:00:1"/>
</Storyboard>