C# Wpf材料设计卡更改代码中的不透明度

我正在用Xaml创建一个如下所示的材质卡

<materialDesign:Card x:Name="CardMainHouseKeeping" Width="112" Height="112" >
    <materialDesign:Card.Effect>
        <DropShadowEffect Color="#FF2ECC71" Direction="266" ShadowDepth="0" BlurRadius="15" Opacity="0.0"/>
    </materialDesign:Card.Effect>
    <Button x:Name="ButtonMainHouseKeeping" Width="112" Height="112" Click="ButtonMainHouseKeepingOnClicked">
    </Button>
</materialDesign:Card>

---

但它不起作用。我该怎么办？

试试cardmainhousing.Effect.BeginAnimation（DropShadowEffect.OpacityProperty，animatePocity）；尝试cardmainhousing.Effect.BeginAnimation（DropShadowEffect.OpacityProperty、animatePocity）；

private void ButtonMainHouseKeepingOnClicked(object sender, RoutedEventArgs e) {
    DoubleAnimation animateOpacity = new DoubleAnimation {
        From = 0,
        To = 0.8,
        Duration = new Duration(new TimeSpan(0, 0, 0, 0, 400))
    };


    CardMainHouseKeeping.BeginAnimation(DropShadowEffect.OpacityProperty, animateOpacity);
}