Silverlight Border FAIL !

Border FAIL !! I have a border in XAML code that is defined right after that main canvas:

<Canvas xmlns="http://schemas.micro开发者_开发知识库soft.com/client/2007"
...      VerticalAlignment="Top" HorizontalAlignment="Center">
    <Border x:Name="JohnnyBorder" BorderThickness="1" Margin="0,0,0,0" BorderBrush="#FF677B8B" VerticalAlignment="Stretch"
            HorizontalAlignment="Center">

And in the code I position the border ike this:

JohnnyBorder = (Border)appCanvas.FindName("JohnnyBorder");
                JohnnyBorder.Height = App.Current.Host.Content.ActualHeight;
                JohnnyBorder.Width = App.Current.Host.Content.ActualWidth;

But it does not work. JohnnyBoarder's bottom line is a few percentages above the bottom of the browser. Why?

I think it would be a lot more natural to have your Border around you Canvas:

<Border>
    <Canvas>
        ...
    </Canvas>
</Border>

By default the Border will fill the page and the Canvas will fill the Border.

The page hosting your silverlight app may not be giving the Silverlight app 100% height. Check either the html or aspx file hosting your silverlight app and ensure it's set to 100% height.

<form id="form1" runat="server" style="height:100%">
<div id="silverlightControlHost">
    <object data="data:application/x-silverlight-2," type="application/x-silverlight-2" width="100%" height="100%">