在WPF DataGrid中使用拖放进行分组

I want to add a "drop" area to the existing WPF DataGrid, above the column headers. In that area I want to allow the user to drop column headers that represent the columns to be grouped and to ungroup those columns by removing them from this area. Xceed, SyncFusion, and other commercial grids provide this functionality but I need to do it myself.I want to add a "drop" area to the existing WPF