winform 两个TreeView间拖拽节点

        /// <summary>
        /// 正在拖拽的节点
        /// </summary>
        private TreeNode DragNode = null;
        /// <summary>
        /// 节点来源
        /// </summary>
        private TreeView NodeSource = null;
        /// <summary>
        /// 树形节点移动方向
        /// </summary>
        private MoveTreeView MoveTo = MoveTreeView.NoMove;

        /// <summary>
        /// 当鼠标拖拽某相进入控件区域内时
        /// </summary>
        private void TreeView_DragEnter(object sender, DragEventArgs e)
        {
            e.Effect = DragDropEffects.Move;
        }

        /// <summary>
        /// 当鼠标拖拽某节点时（两个控件的该事件都指向这个方法）
        /// </summary>
        private void TreeView_ItemDrag(object sender, ItemDragEventArgs e)
        {
            if (e.Item is TreeNode && e.Button == System.Windows.Forms.MouseButtons.Left &&
                e.Item != null && sender is TreeView)
            {
                TreeView trv = sender as TreeView;
                TreeNode node = e.Item as TreeNode;
                if (node.Parent != null && trv.Tag != null)
                {
                    int value = Convert.ToInt32(trv.Tag);
                    MoveTo = (MoveTreeView)value;
                    DragNode = node;
                    NodeSource = trv;
                    trv.DoDragDrop(node, DragDropEffects.Move);
                }
            }
        }

        /// <summary>
        /// 拖拽完成时发生的事件（两个控件的该事件都指向这个方法）
        /// </summary>
        private void TreeView_DragDrop(object sender, DragEventArgs e)
        {
            if (sender != null && sender is TreeView)
            {
                TreeView trv = sender as TreeView;
                if (trv.Tag != null)
                {
                    MoveTreeView move = (MoveTreeView)Convert.ToInt32(trv.Tag);
                    if (move == MoveTo) { DragNode = null; NodeSource = null; }
                    else
                    {
                        Point p = trv.PointToClient(new Point(e.X, e.Y));
                        TreeNode node = trv.GetNodeAt(p);
                        string path = GetClientPath(DragNode, DragNode.Text);
                        NodeSource.Nodes.Remove(DragNode);
                        node.Nodes.Add(DragNode);
                    }
                }
            }
        }

        /// <summary>
        /// 属性节点移动方向
        /// </summary>
        public enum MoveTreeView
        {
            /// <summary>
            /// 未移动
            /// </summary>
            NoMove = -,
            /// <summary>
            /// 上传（客户端拖拽到服务器端）
            /// </summary>
            ClientToServer = ,
            /// <summary>
            /// 下载（服务器端拖拽到客户端）
            /// </summary>
            ServerToClient =
        }

首先要将 TreeView 控件的 AllowDrop 属性置为 True