Silverlihgt滚动条控件ScrollViewer基本用法

今天想让StackPanel在内容越界的时候显示滚动条，找了半天属性没有找到。
原来与Border一样，滚动条也是作为一个单独的附件加上的，呵呵，有趣。
显示上下左右滚动条的方法：
ScrollViewer.HorizontalScrollBarVisibility="Auto"
ScrollViewer.VerticalScrollBarVisibility="Auto"

<UserControl x:Class="HCLoad.uc_ScrollViewer"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">
    
    <Grid x:Name="LayoutRoot" Background="White">
        <ScrollViewer VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto"  Height="100" HorizontalAlignment="Left" Margin="10,10,0,0" Name="scrollViewer1" VerticalAlignment="Top" Width="200">
            <StackPanel Height="200" Width="300" Background="Green">
                <TextBlock Text="hello"></TextBlock>
                <TextBlock Text="hello"></TextBlock>
                <TextBlock Text="hellohellohellohellohellohellohellohellohello"></TextBlock>
                <TextBlock Text="hello"></TextBlock>
                <TextBlock Text="hello"></TextBlock>
                <TextBlock Text="hello"></TextBlock>
            </StackPanel>
        </ScrollViewer>
    </Grid>
</UserControl>