WPF学习笔记：获取ListBox的选中项

<UserControl x:Class="UnitViews.UserListUV"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
>

<StackPanel Orientation="Vertical">
<ListBox x:Name="Lst" ItemsSource="{Binding Path=UserList}" BorderBrush="Transparent">

<i:Interaction.Triggers>
<i:EventTrigger EventName="SelectionChanged">
<i:InvokeCommandAction Command="{Binding SelectionChangedCmd}"
CommandParameter="{Binding ElementName=Lst}" />
</i:EventTrigger>
</i:Interaction.Triggers>

<ListBox.ItemTemplate>
<DataTemplate>
<Grid Height="30">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="25"/>
<ColumnDefinition Width="220"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Image Source="{Binding Path=StrUrlPath}" Style="{StaticResource UserStatusIcon}" Grid.Column="0" />
<TextBlock Text="{Binding Path=StrReMarkName}" Margin="5 0" FontSize="18" Grid.Column="1"></TextBlock>
<Image Source="{Binding Path=CmdIcon}" Style="{StaticResource UserCmdIcon}" Grid.Column="2" />
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</StackPanel>

</UserControl>

DelegateCommand<ListBox> _SelectionChangedCmd = null;
public DelegateCommand<ListBox> SelectionChangedCmd
{
get
{
if (this._SelectionChangedCmd == null)
{
this._SelectionChangedCmd = new DelegateCommand<ListBox>(SelectionChanged);
}

return this._SelectionChangedCmd;
}
}
void SelectionChanged(ListBox lst)
{
SelectedUser = lst.SelectedItem as User;
}
//这个就是选中项啦。User是自定义类
public User SelectedUser { get; set; }