当父级绑定了DataContext之内的数据源时，子级想重新绑回DataContext

<Grid x:Name="NewDeploymentObjectPanel"
Background="White"
DataContext="{Binding Detail}">

　　<Grid Grid.Row="13" DataContext="{Binding DataContext, RelativeSource={RelativeSource AncestorType=UserControl}}">//重新绑回,UserControl是父控件

　　.....

　　</Grid>

</Grid>

 如下是treeitem的数据源重新绑定到treeview上

<TreeView.ItemContainerStyle>
<Style BasedOn="{StaticResource Comprehensive.TreeViewItemStyle}" TargetType="{x:Type TreeViewItem}">
<Style.Resources>
<ContextMenu x:Key="cm" DataContext="{Binding DataContext, RelativeSource={RelativeSource AncestorType=TreeView}}">