Move column headers in xamdatagrid to top of grid
===

I have a hierarchical data model: 

    public class AssetClassLevelViewModel
    {    
         public string AssetClassName {get; set;}
    
         public ObservableCollection<AssetClassLevelViewModel> ChildAssetClasses {get; set;}
    
         public ObservableCollection<ProductHoldingsWithAllocationViewModel> ProductHoldings {get; set;}
    
    }


The column headers seen in the image reflect the ProductHoldingsWithAllocationViewModel properties.

![A snapshot of the multi-level hierarchy and column headers][1]


  [1]: http://i.stack.imgur.com/QxKq7.jpg


I need to move the column headers on top of the grid, and do not want them repeating at each grouping level.

Is there a solution for this? In the xaml I've set the `HeaderPlacement` property to `OnTopOnly` 

Thanks

Hasanain