Xaml (Windows Phone 8 & Silverlight) usercontrol stacking issue

Question

I have a usercontrol that I am placing in a grid. Inside the grid I am also drawing lines. These lines appear above the usercontrol like they should.

When the user clicks on my usercontrol, I am showing another part of the usercontrol, an xaml element (making it visible) and I need it to appear above the drawn lines.

I've tried Canvas.ZIndex. That seems to only work with elements inside my usercontrol. If I set the usercontrols ZIndex high, then it all appears above the lines.

Here is the Min working example:

I need the Blue square to stay below the black line and the yellow ellipse to be above the black line.

--Main Page--

<UserControl xmlns:SWE_UserControlOverlap="clr-namespace:SWE_UserControlOverlap"  x:Class="SWE_UserControlOverlap.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">

    <Grid x:Name="LayoutRoot" Background="White">
        <SWE_UserControlOverlap:SWE />
        <Line Stroke="Black" StrokeThickness="10" Stretch="Fill" X1="0" Y1="0" X2="1" Y2="1"></Line>
    </Grid>
</UserControl>

--UserControl--

<UserControl x:Class="SWE_UserControlOverlap.SWE"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">

    <Grid x:Name="LayoutRoot" Background="White">
        <Rectangle Fill="Blue" MouseLeftButtonUp="Rectangle_MouseLeftButtonUp_1"></Rectangle>
        <Ellipse Margin="100" Fill="Yellow" ></Ellipse>
    </Grid>
</UserControl>

Answer 1

Don't set a ZIndex on the control, just modify it for the sub controls.

<Line Canvas.ZIndex="1" />
<Rectangle Canvas.ZIndex="0" />
<Ellipse Canvas.ZIndex="2" />

Answer 2

正如我在网络上的各个位置所发现的那样-这是不可能的。