How to fire RowValidating event for GridCheckBoxColumn in SfDataGrid in WindowsPhone ?

           
  void sfGrid_CurrentCellValueChanged(object sender, Syncfusion.UI.Xaml.Grid.CurrentCellValueChangedEventArgs args)
    {
        int columnIndex = this.sfGrid.ResolveToGridVisibleColumnIndex(args.RowColumnIndex.ColumnIndex);
 
        //We are enabling the RowValidating event if the changes happen in GridCheckBoxColumn
        if (this.sfGrid.Columns[columnIndex].CellType == "CheckBox")
        {
            this.sfGrid.GetValidationHelper().SetCurrentRowValidated(false);
        }
   }