WPF DataGrid - 查找单击项的列

Question

我在标题中有一个带CheckBoxes的Datagrid。 单击复选框时，我想知道它的索引列。我在Google上找到的所有内容都是指被点击的单元格，而不是标题项目。尽管我在debuging dep Data DataGridColumnHeader时可以看到，但是while循环不会退出。

Xaml：

<DataGridTemplateColumn>
    <DataGridTemplateColumn.HeaderTemplate>
        <DataTemplate>
            <StackPanel Margin="0,-7,0,0" Orientation="Horizontal" VerticalAlignment="Center" HorizontalAlignment="Center">
                    <CheckBox Margin="0,0,5,0" IsChecked="{Binding DataContext.Day1Cb, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}" Click="HeaderCheckBox_Click"></CheckBox>
                <TextBlock Text="{x:Static resx:Bla.Day1}"></TextBlock>
            </StackPanel>
        </DataTemplate>
    </DataGridTemplateColumn.HeaderTemplate>
    <DataGridTemplateColumn.CellTemplate>
        <DataTemplate>
            <StackPanel Orientation="Vertical">
                <TextBlock Text="{Binding Path=Day1}" VerticalAlignment="Center" HorizontalAlignment="Center"/>
            </StackPanel>
        </DataTemplate>
    </DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>

CodeBehind：

private void HeaderCheckBox_Click(object sender, RoutedEventArgs e)
{       
    DependencyObject dep = (DependencyObject)e.OriginalSource;  
    while ((dep != null) && !(dep is DataGridColumnHeader)) 
    {
       dep = VisualTreeHelper.GetParent(dep);
    }

    if (dep == null)
       return;
    if (dep is DataGridColumnHeader)
    {
       DataGridColumnHeader columnHeader = dep as DataGridColumnHeader;
       // do something
    }       
    int columnIndex = NavDataGrid.Columns.Single(c => c == dep).DisplayIndex;       
}

由于