DragDrop TreeView

DragDrop TreeView

la treeview doit avoir sa propriété AllowDrop réglée à true 

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Drawing;

using System.Data;

using System.Text;

using System.Windows.Forms;

namespace NET2CsGenObjects.UI

{

    public partial class UCHierarchy : UserControl

    {

       TreeNode oTreeNodeBase;

        public UCHierarchy()

        {

            InitializeComponent();

            oTreeNodeBase = new TreeNode();

        }

        private void UCHierarchy_Load(object sender, EventArgs e)

        {

            TreeNode ParentNode1;

            TreeNode ParentNode2;

            ParentNode1 = treeView1.Nodes.Add("tv1");

            {

                ParentNode1.Nodes.Add("tv1FirstChild");

                ParentNode1.Nodes.Add("tv1SecondChild");

                ParentNode1.Nodes.Add("tv1ThirdChild");

                ParentNode1.Nodes.Add("tv1FourthChild");

                ParentNode1.Expand();

            }

            ParentNode2 = treeView1.Nodes.Add("tv2");

            {

                ParentNode2.Nodes.Add("tv2FirstChild");

                ParentNode2.Nodes.Add("tv2SecondChild");

                ParentNode2.Expand();

            }

        }

        // 1

        private void treeView1_DragEnter(object sender, DragEventArgs e)

        {

            e.Effect = DragDropEffects.Move;

            Point pt = treeView1.PointToClient(new Point(e.X, e.Y));

            TreeNode targetNode = treeView1.GetNodeAt(pt);

            oTreeNodeBase = targetNode;

        }

        // 2

        private void treeView1_ItemDrag(object sender, ItemDragEventArgs e)

        {

            DoDragDrop(e.Item, DragDropEffects.Move);

        }

        // 3

        private void treeView1_DragDrop(object sender, DragEventArgs e)

        {

            Point pt = treeView1.PointToClient(new Point(e.X, e.Y));

            TreeNode targetNode = treeView1.GetNodeAt(pt);

            string sText = oTreeNodeBase.Text;

            // suppression

            treeView1.Nodes.Remove(oTreeNodeBase);

            // ajout

            targetNode.Nodes.Add(sText);

        }

    }

}