Stretch height of nested ItemsControl

Question

On MainWindow, I have an ItemsControl that I'm adding UserControls to, and said UserControl also contains an ItemsControl containing other UserControls.

The problem is that a lot of items in the second ItemsControl aren't showing because they go past the height of the UserControl as it appears on MainWindow.

How can I make sure the UserControls in the first ItemsControl always stretch enough to show all UserControls in their ItemsControl? For trial and error I tried stretching via a ItemTemplate but that didn't change a thing.

<Window x:Class="X.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <DataTemplate x:Key="DataTemplate1">
            <Grid>
                <Grid.RowDefinitions>
                    <RowDefinition Height="Auto"/>    
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto"/>
                </Grid.ColumnDefinitions>
                <ItemsPresenter Grid.Row="0" Grid.Column="0" DataContext="{Binding}"/>
            </Grid>
        </DataTemplate>
    </Window.Resources>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>
        <ItemsControl Grid.Row="0" x:Name="ic" ItemTemplate="{DynamicResource DataTemplate1}"/>
    </Grid>
</Window>

--

<UserControl x:Class="X.UserControl1"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d" Height="113" Width="209">
    <UserControl.Resources>
        <DataTemplate x:Key="DataTemplate1">
            <Grid>
                <Grid.RowDefinitions>
                    <RowDefinition Height="Auto"/>
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto"/>
                </Grid.ColumnDefinitions>
                <ItemsPresenter DataContext="{Binding}"/>
            </Grid>
        </DataTemplate>
    </UserControl.Resources>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>
        <Label Grid.Row="0" Content="Label" HorizontalAlignment="Left" Margin="10,10,0,0" VerticalAlignment="Top"/>
        <ItemsControl Grid.Row="1" x:Name="ic" Margin="0,36,0,0" ItemTemplate="{DynamicResource DataTemplate1}"/>
    </Grid>
</UserControl>

--

<UserControl x:Class="X.UserControl2"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d" Height="40" Width="64">
    <Grid>
        <Label Content="Label2" HorizontalAlignment="Left" Margin="10,10,0,0" VerticalAlignment="Top"/>

    </Grid>
</UserControl>

Answer 1

Added from my above comment, which turned out to be the problem.

Your UserControls have Height and Width explicitly set, which means they won't automatically resize/stretch to accommodate the child controls as you desire.

Removing the Height (and ideally Width), should do the trick:

<UserControl x:Class="X.UserControl1"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
         mc:Ignorable="d" />
    <!-- Your Code -->         
</UserControl>