[wpf] WPF: ItemsControl with scrollbar (ScrollViewer)

I followed this small "tutorial" on how to add a scrollbar to an ItemsControl, and it works in Designer view, but not when I compile and execute the program (only the first few items show up, and no scrollbar to view more - even when VerticalScrollbarVisibility is set to "Visible" instead of "Auto").

Any idea on how to solve this?

This is the code I use to show my items (normally I work with Databinding, but to see the items in my Designer I added them manually):

<ItemsControl x:Name="itemCtrl" Style="{DynamicResource UsersControlStyle}">
    <ItemsControl.ItemsPanel>
        <ItemsPanelTemplate>
            <StackPanel Orientation="Vertical" HorizontalAlignment="Center" VerticalAlignment="Top">
            </StackPanel>
        </ItemsPanelTemplate>
    </ItemsControl.ItemsPanel>

    <uc:UcSpeler />
    <uc:UcSpeler />
    <uc:UcSpeler />
    <uc:UcSpeler />
    <uc:UcSpeler />
</ItemsControl>

And this is my Template:

<Style x:Key="UsersControlStyle" TargetType="{x:Type ItemsControl}">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type ItemsControl}">
                <Border SnapsToDevicePixels="true" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Padding="{TemplateBinding Padding}">
                    <ScrollViewer VerticalScrollBarVisibility="Visible">
                        <ItemsPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                    </ScrollViewer>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

Put your ScrollViewer in a DockPanel and set the DockPanel MaxHeight property

[...]
<DockPanel MaxHeight="700">
  <ScrollViewer VerticalScrollBarVisibility="Auto">
   <ItemsControl ItemSource ="{Binding ...}">
     [...]
   </ItemsControl>
  </ScrollViewer>
</DockPanel>
[...]

You have to modify the control template instead of ItemsPanelTemplate:

<ItemsControl >
    <ItemsControl.Template>
        <ControlTemplate>
            <ScrollViewer x:Name="ScrollViewer" Padding="{TemplateBinding Padding}">
                <ItemsPresenter />
            </ScrollViewer>
        </ControlTemplate>
    </ItemsControl.Template>
</ItemsControl>

Maybe, your code does not working because StackPanel has own scrolling functionality. Try to use StackPanel.CanVerticallyScroll property.