WPFLearn3 VisalBrush 实现倒影

 <StackPanel>
        <TextBox Name="txtInput" DockPanel.Dock="Top" FontSize="20" Margin="0,20,0,0" Height="60" Width="500"></TextBox>
        <Rectangle Height="60" Width="500" DockPanel.Dock="Top">
            <Rectangle.Fill>
                <VisualBrush Visual="{Binding ElementName=txtInput}">
                    <VisualBrush.RelativeTransform>
                        <TransformGroup>
                            <ScaleTransform ScaleX="1" ScaleY="-1"></ScaleTransform>
                            <TranslateTransform Y="1"></TranslateTransform>
                        </TransformGroup>
                    </VisualBrush.RelativeTransform>
                    
                </VisualBrush>
                
            </Rectangle.Fill>
        </Rectangle>
    </StackPanel>

Result: