如何从DataRow.ContextMenu事件中检索DataRow

Question

如何将DataRow绑定到与该行关联的ContextMenu.MenuItem的Tag属性？这是我到目前为止所知道的：

<DataGrid.Resources>
    <ContextMenu x:Key="RowContextMenu">
        <ContextMenu.Items>
            <!--This line doesnot work-->
            <MenuItem Header="GoToElement" Click="Click_GoToElement" Tag="{Binding RelativeSource={RelativeSource AncestorType=DataGridRow}, Path=Row.Header}"/>
        </ContextMenu.Items>
    </ContextMenu>
</DataGrid.Resources>

<DataGrid.RowStyle>
    <Style TargetType="DataGridRow" BasedOn="{StaticResource {x:Type DataGridRow}}">
        <Setter Property="ContextMenu" Value="{StaticResource RowContextMenu}" />
    </Style>
</DataGrid.RowStyle>

然后，click-event看起来像这样。我收到一个错误:对象引用未设置为对象的实例

private void Click_GoToElement(object sender, RoutedEventArgs e)
{
    try
    {
        var row = ((System.Windows.Controls.MenuItem)sender).Tag;
        MessageBox.Show(row.ToString());
    }
    catch (Exception ex) { MessageBox.Show(ex.Message + "\n" + ex.StackTrace); }
}

Answer 1

绑定到父ContextMenu的PlacementTarget

<MenuItem Header="GoToElement"
          Click="Click_GoToElement"
          Tag="{Binding RelativeSource={RelativeSource AncestorType=ContextMenu}, Path=PlacementTarget.Header}"/>