c# 实现鼠标拖动TreeView节点

private void TVdepartment_ItemDrag(object sender, ItemDragEventArgs e)//左键拖动
        {
            if (e.Button == MouseButtons.Left)
            {
                DoDragDrop(e.Item, DragDropEffects.Move); 
            }
        }

        private void TVdepartment_DragEnter(object sender, DragEventArgs e)
        {
            if (e.Data.GetDataPresent("System.Windows.Forms.TreeNode"))
            {
                e.Effect = DragDropEffects.Move;
            }
            else
            {
                e.Effect = DragDropEffects.None;
            }
        }

    private void TVdepartment_DragDrop(object sender, DragEventArgs e)//拖动
        {    //获得拖放中的节点
            TreeNode moveNode = (TreeNode)e.Data.GetData("System.Windows.Forms.TreeNode");
            //根据鼠标坐标确定要移动到的目标节点
            Point pt;
            TreeNode targeNode;
            pt = ((TreeView)(sender)).PointToClient(new Point(e.X, e.Y));
            targeNode = this.TVdepartment.GetNodeAt(pt);
            //如果目标节点无子节点则添加为同级节点,反之添加到下级节点的未端
            TreeNode NewMoveNode = (TreeNode)moveNode.Clone();
            if (targeNode.Nodes.Count == 0)
            {
                targeNode.Parent.Nodes.Insert(targeNode.Index, NewMoveNode);
            }
            else
            {
                targeNode.Nodes.Insert(targeNode.Nodes.Count, NewMoveNode);
            }
            //更新当前拖动的节点选择
            TVdepartment.SelectedNode = NewMoveNode;
            //展开目标节点,便于显示拖放效果
            targeNode.Expand();

            //移除拖放的节点
            moveNode.Remove();
        }