Example E764
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WinForms Data Grid - How to reorder rows using drag-and-drop

Note:
In v23.2+, the GridView supports the following drag-and-drop operations out of the box:

- Move selected rows to another Grid control.
- Reorder selected rows within the GridView (supported data sources: IList, DataTable, DataView).

Use the GridView.OptionsDragDrop property to configure drag-and-drop operations that users can perform within the GridView.

This example demonstrates how to attach the Drag-and-Drop Behavior to the WinForms Grid Control and handle drag-drop-related events to allow users to reorder data rows using drag-and-drop.

The Behavior describes a functional aspect of a DevExpress WinForms UI control. Read the following help topic for more information: Behaviors.

Attach Drag-and-Drop Behavior to GridView

C#
DragDropBehavior gridControlBehavior = behaviorManager1.GetBehavior<DragDropBehavior>(gridView); gridControlBehavior.DragDrop += Behavior_DragDrop; gridControlBehavior.DragOver += Behavior_DragOver;
Visual Basic
Dim gridControlBehavior As DragDropBehavior = behaviorManager1.GetBehavior(Of DragDropBehavior)(Me.gridView1) AddHandler gridControlBehavior.DragDrop, AddressOf Behavior_DragDrop AddHandler gridControlBehavior.DragOver, AddressOf Behavior_DragOver

Handle the DragOver Event

The DragOver event is handled to display the insert indicator and update the mouse pointer. The DragOverGridEventArgs.GetDragOverGridEventArgs static method is used to calculate drag-and-drop settings (state). These settings are used to specify appropriate event arguments for activating the drag-and-drop functionality:

C#
private void Behavior_DragOver(object sender, DragOverEventArgs e) { DragOverGridEventArgs args = DragOverGridEventArgs.GetDragOverGridEventArgs(e); e.InsertType = args.InsertType; e.InsertIndicatorLocation = args.InsertIndicatorLocation; e.Action = args.Action; Cursor.Current = args.Cursor; args.Handled = true; }
Visual Basic
Private Sub Behavior_DragOver(ByVal sender As Object, ByVal e As DragOverEventArgs) Dim args As DragOverGridEventArgs = DragOverGridEventArgs.GetDragOverGridEventArgs(e) e.InsertType = args.InsertType e.InsertIndicatorLocation = args.InsertIndicatorLocation e.Action = args.Action Cursor.Current = args.Cursor args.Handled = True End Sub

Handle the DragDrop Event

The DragDrop event is handled to reorder data rows in the data source.

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Example Code

E764/Form1.cs(vb)
C#
using DevExpress.Utils.DragDrop; using DevExpress.XtraGrid; using DevExpress.XtraGrid.Views.Grid; using DevExpress.XtraGrid.Views.Grid.ViewInfo; using System.Collections.Generic; using System.Data; using System.Drawing; using System.Windows.Forms; namespace E764 { public partial class Form1 : DevExpress.XtraEditors.XtraForm { public Form1() { InitializeComponent(); SetUpGrid(this.gridControl1, FillTable()); HandleBehaviorDragDropEvents(); } public DataTable FillTable() { DataTable table = new DataTable(); table.Columns.Add("ID", typeof(int)); table.Columns.Add("Keyword"); table.Columns.Add("Order", typeof(decimal)); table.Rows.Add(new object[] { 1, "abstract", 1 }); table.Rows.Add(new object[] { 2, "event", 2 }); table.Rows.Add(new object[] { 3, "new", 3 }); table.Rows.Add(new object[] { 4, "struct", 4 }); table.Rows.Add(new object[] { 5, "as", 5 }); table.Rows.Add(new object[] { 6, "explicit", 6 }); table.Rows.Add(new object[] { 7, "null", 7 }); table.Rows.Add(new object[] { 8, "switch", 8 }); table.Rows.Add(new object[] { 9, "base", 9 }); table.Rows.Add(new object[] { 10, "extern", 10 }); table.Rows.Add(new object[] { 11, "object", 11 }); table.Rows.Add(new object[] { 12, "this", 12 }); table.Rows.Add(new object[] { 13, "bool", 13 }); table.Rows.Add(new object[] { 14, "false", 14 }); table.Rows.Add(new object[] { 15, "operator", 15 }); table.Rows.Add(new object[] { 16, "throw", 16 }); table.Rows.Add(new object[] { 17, "break", 17 }); return table; } public void SetUpGrid(GridControl grid, DataTable table) { GridView view = grid.MainView as GridView; grid.DataSource = table; view.OptionsBehavior.Editable = false; } public void HandleBehaviorDragDropEvents() { DragDropBehavior gridControlBehavior = behaviorManager1.GetBehavior<DragDropBehavior>(this.gridView1); gridControlBehavior.DragDrop += Behavior_DragDrop; gridControlBehavior.DragOver += Behavior_DragOver; } private void Behavior_DragOver(object sender, DragOverEventArgs e) { DragOverGridEventArgs args = DragOverGridEventArgs.GetDragOverGridEventArgs(e); e.InsertType = args.InsertType; e.InsertIndicatorLocation = args.InsertIndicatorLocation; e.Action = args.Action; Cursor.Current = args.Cursor; args.Handled = true; } private void Behavior_DragDrop(object sender, DevExpress.Utils.DragDrop.DragDropEventArgs e) { GridView targetGrid = e.Target as GridView; GridView sourceGrid = e.Source as GridView; if (e.Action == DragDropActions.None || targetGrid != sourceGrid) return; DataTable sourceTable = sourceGrid.GridControl.DataSource as DataTable; Point hitPoint = targetGrid.GridControl.PointToClient(Cursor.Position); GridHitInfo hitInfo = targetGrid.CalcHitInfo(hitPoint); int[] sourceHandles = e.GetData<int[]>(); int targetRowHandle = hitInfo.RowHandle; int targetRowIndex = targetGrid.GetDataSourceRowIndex(targetRowHandle); List<DataRow> draggedRows = new List<DataRow>(); foreach (int sourceHandle in sourceHandles) { int oldRowIndex = sourceGrid.GetDataSourceRowIndex(sourceHandle); DataRow oldRow = sourceTable.Rows[oldRowIndex]; draggedRows.Add(oldRow); } int newRowIndex; switch (e.InsertType) { case InsertType.Before: newRowIndex = targetRowIndex > sourceHandles[sourceHandles.Length - 1] ? targetRowIndex - 1 : targetRowIndex; for (int i = draggedRows.Count - 1; i >= 0; i--) { DataRow oldRow = draggedRows[i]; DataRow newRow = sourceTable.NewRow(); newRow.ItemArray = oldRow.ItemArray; sourceTable.Rows.Remove(oldRow); sourceTable.Rows.InsertAt(newRow, newRowIndex); } break; case InsertType.After: newRowIndex = targetRowIndex < sourceHandles[0] ? targetRowIndex + 1 : targetRowIndex; for (int i = 0; i < draggedRows.Count; i++) { DataRow oldRow = draggedRows[i]; DataRow newRow = sourceTable.NewRow(); newRow.ItemArray = oldRow.ItemArray; sourceTable.Rows.Remove(oldRow); sourceTable.Rows.InsertAt(newRow, newRowIndex); } break; default: newRowIndex = -1; break; } int insertedIndex = targetGrid.GetRowHandle(newRowIndex); targetGrid.FocusedRowHandle = insertedIndex; targetGrid.SelectRow(targetGrid.FocusedRowHandle); } } }
E764/Program.cs(vb)
C#
using System; using System.Windows.Forms; namespace E764 { static class Program { [STAThread] static void Main() { Application.Run(new Form1()); } } }

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