WPF为stackpanel设置滚动条

最新遇到ItemControl控件增加滚动条功能，找半天还是在StackPanel模板外添加的。

<ScrollViewer x:Name="scrolls" VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto" Height="300">
            <ScrollViewer.Content>
                <StackPanel x:Name="numberedItemsStackPanel" Orientation="Horizontal"   ScrollViewer.VerticalScrollBarVisibility="Auto">
                    …………………………………………
                </StackPanel>
            </ScrollViewer.Content>
</ScrollViewer>