SfDataGrid Row drag to reorder when using Grouping

[Michael Eick]

I have a SfDataGrid, and am using the row drag to let the user reorder steps; the item source is  List<StepDTO>, and mu code is like this:

private void SfGrid_QueryRowDragging(object sender, QueryRowDraggingEventArgs e)
{
 if (e.Reason == QueryRowDraggingReason.DragEnded)
 {
  int startIdx = e.From - 1;
  int endIdx = e.To - 1;
  StepDTO s = m_plan.StepList[startIdx];
  m_plan.StepList.RemoveAt(startIdx);
  m_plan.StepList.Insert(endIdx, s);
 }
}

This works great, and I like this control! But now I want to use Grouping, and got it in place and working fine. But, when the RowDragging event is called, the indexes are NOT my item indexes but rather the grid indexes which include the group header rows. So ... crash me.

I am hacling something up that might work, but would rather find out I am missing an easy trick!

Any ideas?

Thanks, Mike

[Pavithra Sivakumar]

Hi Michael, 

 

Thanks for contacting Syncfusion support. 

 

We have checked your query. We have prepared a sample based on it which can be downloaded from the below link. 

 

Sample Link: https://www.syncfusion.com/downloads/support/directtrac/130764/ze/DragingAndGrouping-1348196632 

 

Regards, 

Pavithra S 

[Michael Eick]

Thanks for the quick response. A couple of questions:1. Is it true that this code only allows drag within a group?2. What is the Task.Delay(3000) for? 3 seconds is a long time ...EDIT: Implemented the sample, but the sfGrid.CurrentItem is always null. Sigh.Regards, Mike

[Pavithra Sivakumar]

 

Hi Michael, 

 

1.     Regarding your first query of “Is it true that this code only allows drag within a group?” 

 

Yes, it allows drag only within a group. If you want drag among all groups, please refer the below code example. 

 

private void DataGrid_QueryRowDragging(object sender, QueryRowDraggingEventArgs e) 

{ 

       if (e.Reason == QueryRowDraggingReason.DragEnded) 

       { 

             if (dataGrid.GroupColumnDescriptions.Count == 0) 

             { 

 

                    int startIndex = e.From - 1; 

                    int endIndex = e.To - 1; 

                    OrderInfo orderInfo = viewModel.OrdersInfo[startIndex]; 

                    viewModel.OrdersInfo.RemoveAt(startIndex); 

                    viewModel.OrdersInfo.Insert(endIndex, orderInfo); 

             } 

             else 

            { 

                     var currentOrderInfo = e.CurrentRowData as OrderInfo; 

                     var draggedOrderInfo = e.RowData as OrderInfo; 

                     int currentOrderInfoCollectionIndex = this.viewModel.OrdersInfo.IndexOf(currentOrderInfo); 

                     int draggedOrderInfoCollectionIndex = this.viewModel.OrdersInfo.IndexOf(draggedOrderInfo); 

                     viewModel.OrdersInfo.Remove(draggedOrderInfo); 

                     if (e.From > e.To) 

                         viewModel.OrdersInfo.Insert(currentOrderInfoCollectionIndex, draggedOrderInfo); 

                     else 

                         viewModel.OrdersInfo.Insert(currentOrderInfoCollectionIndex + 1, draggedOrderInfo);                          

              } 

      } 

} 

 

2.     Regarding your second query of “ What is the Task.Delay(3000) for? 3 seconds is a long time ...”  

 

Task.Delay is to improve the performance. You can reduce the delay time for your convenience. 

 

3.     Regarding your third query of “Implemented the sample, but the sfGrid.CurrentItem is always null.” 

 

Sorry for the mistake. This condition is not needed. 

 

Regards, 

Pavithra S