How to make items in a DockPanel expand to fit all available space in WPF?

Question

I have a StackPanel containing a StackPanel and some other items. The first StackPanel has a vertical orientation, the the inner one has a horizontal orientation. The inner one has a TreeView and a ListView, I would like them to expand and fit the width of the window, which I set by the window and allow the user to change. I would also like the outer StackPanel to fit the height of the window. How do I do this?

Edit: I've converted to using a DockPanel, and I've set the DockPanel.Dock properties correctly in each of the elements, and have disabled LastChildFill in both of the dockpanels, the layout still does not stretch.

The Code:

<Window x:Class="Clippy.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="400" Width="600" MinHeight="400" MinWidth="600" Loaded="Window_Loaded" SizeChanged="Window_SizeChanged">
    <DockPanel Name="wrapperDockPanel" LastChildFill="False">
        <Menu Height="22" Name="mainMenu" Width="Auto" DockPanel.Dock="Top" />
        <ToolBar Height="26" Name="mainToolBar" Width="Auto" DockPanel.Dock="Top" />
        <DockPanel Height="Auto" Name="contentDockPanel" DockPanel.Dock="Top" LastChildFill="False">
            <TreeView Name="categoryTreeView" />
            <ListView Name="clipListView" />
        </DockPanel>
        <StatusBar Height="23" Name="mainStatusBar" DockPanel.Dock="Top" />
    </DockPanel>
</Window>

Answer 1

Use a DockPanel instead. StackPanel explicitly doesn't care about visible space, whereas DockPanel does all of it's size calculation based on available space.

Update:

In addition, in my experience, putting the body of the window into a View, and only having the View in the Window makes for a better Auto Size experience.

For some reason putting all of the children directly into the Window seems to not auto size very well.

Update 2:

I would remove the explicit DockPanel.Dock attribute from the element that you want to stretch (fill) the unused space.