PopUp in Silverlight is not being clipped by container control

Simple, yet frustrating issue here...

I have a PopUp control.

It is contained in side a Grid, which has a Grid.Clip defined.

The PopUp is still visible outside the Grid's clipped area.

i.e.

<Grid Background="Red" Width="150" Height="150">
    <Grid.Clip>
        <RectangleGeometry Rect="0,0,150,150" />
    </Grid.Clip>
    <Popup IsOpen="True" Margin="100,100,0,0">
        <Grid Background="G开发者_高级运维reen" Width="150" Height="150" />
    </Popup>
</Grid>

Ideally, the green box should not appear or "bleed" outside of the red box. The problem is that it is contained within a PopUp, and so it bleeds. How can I modify this (without removing the PopUp control) so that the PopUp does not bleed outside of it's containing control?

---

Popup works differently. It "ignores" its parent and it is added directly into visual root of your app. This is how it can be on-top of everything.

So now it depends on what are you trying to do. I think popup is not suitable for this scenario. You can try to clip the popup in its template, but I feel that's not what you want.