Question

I have this:

<Window x:Class="ScrollTest.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow"
        Height="450"
        Width="525">
    <ScrollViewer ScrollViewer.HorizontalScrollBarVisibility="Visible"
                  ScrollViewer.VerticalScrollBarVisibility="Visible">
        <Grid>
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto" />
                <RowDefinition Height="*" />
            </Grid.RowDefinitions>

            <GroupBox Grid.Row="0"
                      Header="Stuff"
                      Height="200">
                <TextBlock Text="Lots of controls go here"
                           HorizontalAlignment="Center"
                           VerticalAlignment="Center" />
            </GroupBox>
            <TabControl Grid.Row="1">
                <TabItem Header="Main Tab">
                    <TextBox MinHeight="100"
                             HorizontalAlignment="Stretch"
                             VerticalAlignment="Stretch"
                             HorizontalContentAlignment="Left"
                             VerticalContentAlignment="Top"
                             ScrollViewer.HorizontalScrollBarVisibility="Visible"
                             ScrollViewer.VerticalScrollBarVisibility="Visible"
                             AcceptsReturn="True" />
                </TabItem>
            </TabControl>
        </Grid>
    </ScrollViewer>
</Window>

When I add too many rows into the TextBox, instead of the ScrollViewer of the TextBox being used, the box stretches and the outermost ScrollViewer is used. Can I prevent that without fixing the height of the TextBox or TabControl?

Update:

If I remove MinHeight on the TextBox and set MaxLines to 5, this is what I get:

If I added a 6th line, the scroll bars of the TextBox‘s ScrollViewer are used, but they still remain centered vertically in the TextBox control.

Answer 1

I was able to get close with this:

<Window x:Class="ScrollTest.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow"
        Width="525">
    <ScrollViewer ScrollViewer.VerticalScrollBarVisibility="Visible"
                  x:Name="Base">
        <Grid Height="{Binding ElementName=Base, Path=ActualHeight, Mode=OneWay}"
              MinHeight="400">
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto" />
                <RowDefinition Height="*" />
            </Grid.RowDefinitions>

            <GroupBox Grid.Row="0"
                      Header="Stuff"
                      Height="200">
                <TextBlock Text="Lots of controls go here"
                           HorizontalAlignment="Center"
                           VerticalAlignment="Center" />
            </GroupBox>
            <TabControl Grid.Row="1">
                <TabItem Header="Main Tab">
                    <Grid x:Name="myInnerGrid">
                        <TextBox MinHeight="100"
                                 MaxHeight="{Binding ElementName=myInnerGrid, Path=ActualHeight, Mode=OneWay}"
                                 HorizontalAlignment="Stretch"
                                 VerticalAlignment="Stretch"
                                 HorizontalContentAlignment="Left"
                                 VerticalContentAlignment="Top"
                                 ScrollViewer.HorizontalScrollBarVisibility="Visible"
                                 ScrollViewer.VerticalScrollBarVisibility="Visible"
                                 AcceptsReturn="True" />
                    </Grid>
                </TabItem>
            </TabControl>
        </Grid>
    </ScrollViewer>
</Window>

Note the binding expression on height for the outside grid and on MaxHeight for the TextBox.

It’s still not perfect in that you have to manually set the MinHeight that will trigger the outer most scrollbar. It’s probably as close as WPF will allow without writing a new grid control.

The idea was found here:
http://social.msdn.microsoft.com/Forums/en/wpf/thread/7b4b0c88-6b8f-4f07-aa8b-8e7018762388