WPF Limit Extender Size

Question

I have several treeviews inside expanders that can grow in height along with the content. But when the height becomes larger than the size of the window, it goes beyond the window.

The obvious solution would be to set MaxHeight in Treeview, but I cannot easily determine it, because the available height depends on

• Window height
• Other extensions (open / closed)

What do I need to change to increase the height of the tree, but not more than the height of the window?

<StackPanel CanVerticallyScroll="True" ClipToBounds="False" Height="Auto" Name="StackPanel2" Width="250" DockPanel.Dock="Left" Orientation="Vertical" VerticalAlignment="Top" CanHorizontallyScroll="False" Margin="5">
    <Border BorderThickness="0" CornerRadius="5" Padding="1" BorderBrush="Red" Margin="0,5" >
        <Expander Header="Expander3" Height="Auto" IsExpanded="False" Width="Auto" Margin="2" BorderThickness="1">
           <Grid  Height="Auto" Width="Auto" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" >

            <TreeView Height="Auto" BorderThickness="1" Margin="0,0,0,0" Padding="7" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" >
           </TreeView>

        </Grid>
    </Expander>
    </Border>
</StackPanel>

Answer 1

, , - StackPanel ScrollViewer. , . ( StackPanel?), 100%, .

<ScrollViewer Name="stackPanelScrollViewer"
              Loaded="stackPanelScrollViewer_Loaded"
              VerticalScrollBarVisibility="Auto">
    <StackPanel CanVerticallyScroll="True" ClipToBounds="False" Height="Auto" Name="StackPanel2" Width="250" DockPanel.Dock="Left" Orientation="Vertical" VerticalAlignment="Top" CanHorizontallyScroll="False" Margin="5">
        <Border BorderThickness="0" CornerRadius="5" Padding="1" BorderBrush="Red" Margin="0,5" >
            <Expander Header="Expander3" Height="Auto" IsExpanded="False" Width="Auto" Margin="2" BorderThickness="1">
                <Grid  Height="Auto" Width="Auto" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" >
                    <TreeView Name="treeView1" Height="Auto" BorderThickness="1" Margin="0,0,0,0" Padding="7" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" >
                    </TreeView>
                </Grid>
            </Expander>
        </Border>
    </StackPanel>
</ScrollViewer>

, TreeView ScrollViewer, ControlTemplate, MouseWheel, TreeView. - MouseWheel TreeView

private void stackPanelScrollViewer_Loaded(object sender, RoutedEventArgs e)
{
    treeView1.AddHandler(MouseWheelEvent, new RoutedEventHandler(StackPanelMouseWheel), true);
    //treeView2.AddHandler(MouseWheelEvent, new RoutedEventHandler(StackPanelMouseWheel), true);
}
private void StackPanelMouseWheel(object sender, RoutedEventArgs e)
{
    MouseWheelEventArgs eargs = (MouseWheelEventArgs)e;
    double x = (double)eargs.Delta;
    double y = stackPanelScrollViewer.VerticalOffset;
    stackPanelScrollViewer.ScrollToVerticalOffset(y - x);
}