WPF Dock Panel layout, Expander on top, Windows Forms Host on botton and Fills

Question

I am trying to get my Expander control to appear on top of my Windows Forms Host on my main page and have the Windows Forms Host Fill all remaining area.

However, the Expander appears to the side of it, not on top.

Here is, basically, what I have so far. I left out the extra stuff.

<telerik:RadDockPanel x:Name="LaunchScreenDockPanel" LastChildFill="True">
    <telerik:RadExpander x:Name="UserInfo" ExpandDirection="Up" IsExpanded="True"></telerik:RadExpander>
    <WindowsFormsHost HorizontalAlignment="Stretch" Name="windowsFormsHost1" VerticalAlignment="Stretch" >           
        <wincontrols:RadPanorama x:Name="LaunchPadPanorama" Size="200,400" RowsCount="2" MinimumColumns="2" ShowGroups="True" Dock="Fill">

Answer 1

尝试这个：

<telerik:RadExpander telerik:RadDockPanel.Dock="Top" .../>