How to drag & drop within GridView (Unbound)

[Bala]

Hello, 
I am using RadControls for WinForms 2011 Q3 
RadGridView,  it is in unbound mode.
 
I want to reorder the row. Say I drag the row 1 and drop it to row 4. 
but it does not work. I guess somehow I must miss something, please help.  thanks !

public init()
{
            InitializeComponent();
            InitializePreviewGrid();
            SubscribeForGridEvents(radGridViewPreview);    
}
        List<PreviewItem> _previewLists = new List<PreviewItem>();
        private void InitializePreviewGrid()
        {
            radGridViewPreview.AutoGenerateColumns = false;
            var imageCol = new GridViewImageColumn("DeleteIcon", "DeleteIcon");
            imageCol.HeaderText = "";
            imageCol.Width = 30;
            radGridViewPreview.Columns.Add(imageCol);

            var col = new GridViewTextBoxColumn("DisplayStr", "DisplayStr");
            col.Width = 350;
            radGridViewPreview.Columns.Add(col);

            col = new GridViewTextBoxColumn("ValueStr", "ValueStr");
            col.IsVisible = false;
            radGridViewPreview.Columns.Add(col);

            radGridViewPreview.AllowDeleteRow = false;
            radGridViewPreview.AllowAddNewRow = false;
            radGridViewPreview.AllowEditRow = false;
            radGridViewPreview.AutoScroll = true;
            radGridViewPreview.AllowAutoSizeColumns = true;

            radGridViewPreview.MasterTemplate.AllowRowReorder = true;
            radGridViewPreview.ReadOnly = true;
            radGridViewPreview.MultiSelect = true;
            radGridViewPreview.MasterTemplate.AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.Fill;

            radGridViewPreview.GridBehavior = new CustomGridBehavior();
        }

        private void SubscribeForGridEvents(RadGridView grid)
        {
            dragDropService = grid.GridViewElement.GetService<RadDragDropService>();
            dragDropService.PreviewDragOver += dragDropService_PreviewDragOver;
            dragDropService.PreviewDragDrop += dragDropService_PreviewDragDrop;
            dragDropService.PreviewDragHint += dragDropService_PreviewDragHint;
            dragDropService.PreviewDropTarget += dragDropService_PreviewDropTarget;
            dragDropService.PreviewDragStart += dragDropService_PreviewDragStart;
        }

       void dragDropService_PreviewDragStart(object sender, PreviewDragStartEventArgs e)
        {
            //throw new NotImplementedException();
        }

        void dragDropService_PreviewDropTarget(object sender, PreviewDropTargetEventArgs e)
        {
            //throw new NotImplementedException();
        }
        
        private void dragDropService_PreviewDragDrop(object sender, RadDropEventArgs e)
        {
            var rowElement = e.DragInstance as GridDataRowElement;
            if (rowElement == null)
            {
                return;
            }

            var dropTarget = e.HitTarget as RadItem;
            var targetGrid = dropTarget.ElementTree.Control as RadGridView;
            if (targetGrid == null)
            {
                return;
            }

            var dragGrid = rowElement.ElementTree.Control as RadGridView;
            if (targetGrid != dragGrid)
            {
                e.Handled = true;

                var behavior = (CustomGridBehavior)dragGrid.GridBehavior;
                var dropTargetRow = dropTarget as GridDataRowElement;
                int index = dropTargetRow != null ? GetTargetRowIndex(dropTargetRow, e.DropLocation) : targetGrid.RowCount;
                MoveRows(targetGrid, dragGrid, behavior.SelectedRows, index);
            }
        }

        private void dragDropService_PreviewDragOver(object sender, RadDragOverEventArgs e)
        {
            if (e.DragInstance is GridDataRowElement)
            {
                e.CanDrop = e.HitTarget is GridDataRowElement || e.HitTarget is GridTableElement || e.HitTarget is GridSummaryRowElement;
            }
        }

        private void dragDropService_PreviewDragHint(object sender, PreviewDragHintEventArgs e)
        {
            GridDataRowElement dataRowElement = e.DragInstance as GridDataRowElement;

            if (dataRowElement != null && dataRowElement.ViewTemplate.MasterTemplate.SelectedRows.Count > 1)
            {
                //e.DragHint = new Bitmap(this.imageList1.Images[6]);
                e.UseDefaultHint = false;
            }
        }

        private void MoveRows(RadGridView targetGrid, RadGridView dragGrid, IList<GridViewRowInfo> dragRows, int index)
        {
            for (int i = dragRows.Count - 1; i >= 0; i--)
            {
                GridViewRowInfo row = dragRows[i];

                if (row is GridViewSummaryRowInfo)
                {
                    continue;
                }

                GridViewRowInfo newRow = targetGrid.Rows.NewRow();
                this.InitializeRow(newRow, row);
                targetGrid.Rows.Insert(index, newRow);
                row.IsSelected = false;
                dragGrid.Rows.Remove(row);
                index++;
            }
        }

        private void InitializeRow(GridViewRowInfo destRow, GridViewRowInfo sourceRow)
        {
            destRow.Cells["DisplayStr"].Value = sourceRow.Cells["DisplayStr"].Value;
            destRow.Cells["ValueStr"].Value = sourceRow.Cells["ValueStr"].Value;
        }

        private int GetTargetRowIndex(GridDataRowElement row, Point dropLocation)
        {
            int halfHeight = row.Size.Height / 2;
            int index = row.RowInfo.Index;

            if (dropLocation.Y > halfHeight)
            {
                index++;
            }

            return index;
        }

[Emanuel Varga]

Hello Bala,

Is the unbound drag drop a requirement here? 
Please take a look at the code library project here for a full bound d&d solution.

Best Regards,
Emanuel Varga, MVP

[Stefan]

Hi Bala,

Thank you for writing.

Row reordering is supported by default in unbound mode. Just set the following property to enable it:

radGridView1.AllowRowReorder

If you are looking for a drag and drop, besides Emanuel's article, you can also have a look at the following blog post: http://blogs.telerik.com/winformsteam/posts/13-05-15/extending-radgridview-to-enable-row-drag-and-drop-functionality.

I hope this helps.
 
Regards,
Stefan
Telerik

[Bala]

Thank you very much! 
I got it working by tweeking example from http://blogs.telerik.com/winformsteam/posts/13-05-15/extending-radgridview-to-enable-row-drag-and-drop-functionality.

Now another issue needs your help
I have a radListView, I want to drag items from radListView to the radGridView
So the radGridView can accept dragged items from itself & radListView 
Do you have any example for this?

Thanks 

[Stefan]

Hi Bala,

We do not have such an example, however you can easily achieve the desired behavior by using the same drag and drop service on RadListView. Attached you can find a sample which aims to put you on the right track.

I hope that you find this useful.

Regards,
Stefan
Telerik

[Bhavesh]

Hi,
I have updated extended radgridview example  and add AllowRowReorder but still its not working. Can you please help me.
public Form1()
        {
            InitializeComponent();
            leftGrid.ShowGroupPanel = false;
            rightGrid.ShowGroupPanel = false;
            leftGrid.AllowAddNewRow = false;
            rightGrid.AllowAddNewRow = false;
            leftGrid.AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.Fill;
            rightGrid.AutoSizeColumnsMode = GridViewAutoSizeColumnsMode.Fill;
            leftGrid.AllowRowReorder = true;
            rightGrid.AllowRowReorder = true;
        }

Thanks

[Stefan]

Hello Bhavesh,

To add row reordering in the drag and drop solution from the blog, you have to add an else statement handling this case in the svc_PreviewDragDrop event handler. Here is how it should look like:

private void svc_PreviewDragDrop(object sender, RadDropEventArgs e)
   {
       var rowElement = e.DragInstance as GridDataRowElement;

       if (rowElement == null)
       {
           return;
       }
       e.Handled = true;

       var dropTarget = e.HitTarget as RadItem;
       var targetGrid = dropTarget.ElementTree.Control as RadGridView;
       if (targetGrid == null)
       {
           return;
       }

       var dragGrid = rowElement.ElementTree.Control as RadGridView;
       if (targetGrid != dragGrid)
       {
           e.Handled = true;
           //append dragged rows to the end of the target grid
           int index = targetGrid.RowCount;

           //Grab every selected row from the source grid, including the current row
           List<GridViewRowInfo> rows =
                               dragGrid.SelectedRows.ToList<GridViewRowInfo>();
           if (dragGrid.CurrentRow != null)
           {
               GridViewRowInfo row = dragGrid.CurrentRow;
               if (!rows.Contains(row))
                   rows.Add(row);
           }
           this.MoveRows(targetGrid, dragGrid, rows, index);
       }
       else if (dragGrid.SelectedRows.Count ==1)
       {
           int oldIndex = -1;
           int newIndex = dragGrid.Rows.Count-1;
           for (int i = 0; i < dragGrid.Rows.Count; i++)
           {
               if (dragGrid.Rows[i] == rowElement.RowInfo)
               {
                   oldIndex = i;
               }

               if (dropTarget is GridDataRowElement && dragGrid.Rows[i] == ((GridDataRowElement)dropTarget).RowInfo)
               {
                   newIndex = i;
               }

           }
           e.Handled = true;
           dragGrid.Rows.Move(oldIndex, newIndex);
       }
   }

I hope this helps.

Regards,
Stefan
Telerik