WPF Scrollviewer does not let me scroll and thinks its hight is infinite

Question

I have got a little problem that I am unable to fix. The problem is that when I initialise scrollbar, it does not stay only in screen. To be more specific, its height is actually set to "auto", I think, because it does not let me scroll and it goes to infinite. On the other hand, when I set height to "500" it lets me scroll through it and everything works fine.

Main window:

<Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"></RowDefinition>

            <RowDefinition Height="*"></RowDefinition>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="300"></ColumnDefinition>

            <ColumnDefinition Width="Auto"></ColumnDefinition>
            <ColumnDefinition Width="Auto"></ColumnDefinition>

            <ColumnDefinition Width="*"></ColumnDefinition>
        </Grid.ColumnDefinitions>

        <!-- 
        <Frame x:Name="MainFrame" Grid.Row ="1" Grid.Column="1" Content="{Binding CurrPage}" Source="../pages/test_page.xaml" />
        
        -->
        <Grid Height="500">
            <local:MessageList>
                <local:ChatListControl VerticalAlignment="Top">

                </local:ChatListControl>
            </local:MessageList>
        </Grid>

    </Grid>

Chat list Control (the place where scrollbar is):

<Grid DataContext="{x:Static local:ChatsDesignModule.Instance}" Background="White">

        <ScrollViewer VerticalScrollBarVisibility="Visible">
            <ItemsControl ItemsSource="{Binding Items}">
                <ItemsControl.ItemTemplate>
                    <DataTemplate>
                        <local:OneMessageTMP />
                    </DataTemplate>
                </ItemsControl.ItemTemplate>
            </ItemsControl>
        </ScrollViewer>

    </Grid>

Is there a way how can I bind in the first window the current size just by binding it to something already pre-existing or I have to somehow get the current max value and then set it using that one ? Thanks in advance. If you have any question on the code, please let me know, I will explain / provide more code if needed :)

Answer 1

set Height="Auto" to Height="*". Height="Auto" will give the content of the grid row as much space as it wants. Thus the scroll viewer has nothing to scroll on.