转：http://www.cnblogs.com/mantian/p/3713524.html
将所有的事件，属性，都映射到ViewModel中。好处多多，以后开发尽量用这种模式。
解决方法：
使用System.Windows.Interactivity.dll，添加该dll到项目引用
|
1
|
xmlns:i=
"clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
|
ComboBox映射的代码：
<ComboBox VerticalAlignment="Center" HorizontalAlignment="Left" MinWidth="120" Margin="10,0,0,0"
x:Name="cboTest"
DisplayMemberPath="FamilyName"
SelectedValuePath="IdFamily"
IsReadOnly="True"
ItemsSource="{Binding ListFamily}"
SelectedValue="{Binding Path=ViewModel.SelectedFamilyNameID, Mode=TwoWay, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type UserControl}}}"
Validation.ErrorTemplate="{x:Null}"
Visibility="{Binding ComboBoxVisibility}"
>
<i:Interaction.Triggers>
<i:EventTrigger EventName="SelectionChanged">
<i:InvokeCommandAction Command="{Binding FamilySelectionChangedCommand}"
CommandParameter="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type UserControl}},Path=DataContext}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</ComboBox>
