Button with OpacityMask


   
      

<Window x:Class="OpacityMaskExample"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title=""
  Height="430" Width="300">
  <Grid>
        <Button Height="60" Width="60"
          RenderTransformOrigin="1,0.5">
          <Button.OpacityMask>
            <LinearGradientBrush StartPoint="0,0"
              EndPoint="0,1">
              <GradientStop Color="Transparent"
                Offset="0" />
              <GradientStop Color="#77000000" Offset="1" />
            </LinearGradientBrush>
          </Button.OpacityMask>
          <Button.RenderTransform>
            <ScaleTransform ScaleY="-1" />
          </Button.RenderTransform>
        </Button>
  </Grid>
</Window>