我想知道如何创建这个绑定,因为Line.X2不是依赖属性! :(
<Line Y1="0" X1="0" Y2="0" Stroke="Blue" StrokeThickness="3" Margin="0 -2 0 -2" X2="{Binding Path=RenderSize.Width, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type StackPanel}}}"/>