Silverlight：MouseDragElementBehavior无法应用于ListBox的变相解决办法

Blend自带的行为MouseDragElementBehavior应用到ListBox后，如果用鼠标按住列表列拖动，没有任何效果，在多次尝试中意外发现，如果将ListBox的边框设置成一个较大值，在边框上点击时，却可以拖动，但是一般开发中，没人会把ListBox设置一个粗粗的难看边框。于是想到了下面的变通解决办法：当鼠标进入时显示边框，鼠标离开时再隐藏边框。

示例代码：

Xaml部分

<UserControl
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"
xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity" xmlns:ei="http://schemas.microsoft.com/expression/2010/interactions" x:Class="sl_drag_sample.MainPage"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="400">

<Grid x:Name="LayoutRoot" Background="White">

<ListBox x:Name="lbSample" MinHeight="50" MinWidth="100"  BorderThickness="0" HorizontalAlignment="Center" VerticalAlignment="Center" MouseEnter="ShowBorder"  MouseLeftButtonUp="HideBorder" MouseLeftButtonDown="ShowBorder"  MouseMove="ShowBorder" MouseLeave="HideBorder">
<i:Interaction.Behaviors>
<ei:MouseDragElementBehavior/>
</i:Interaction.Behaviors>
<ListBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="这是测试文字">
<i:Interaction.Behaviors>
<ei:MouseDragElementBehavior/>
</i:Interaction.Behaviors>
</TextBlock>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
</UserControl>

　　

Xaml.cs部分

using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;

namespace sl_drag_sample
{
public partial class MainPage : UserControl
{
public MainPage()
{
InitializeComponent();

this.Loaded += new RoutedEventHandler(MainPage_Loaded);
}

void MainPage_Loaded(object sender, RoutedEventArgs e)
{
char[] s = "ABCDE".ToCharArray();
lbSample.ItemsSource = s;
}

private void ShowBorder(object sender, MouseEventArgs e)
{
(sender as ListBox).BorderThickness = new Thickness(20.0);
}

private void HideBorder(object sender, MouseEventArgs e)
{
(sender as ListBox).BorderThickness = new Thickness(0.0);
}
}
}