c# 实现鼠标拖拽TreeView节点

 

        // 2009-08-25 Jacky
        #region TreeNode拖拽功能
        private void tvStorage_ItemDrag(object sender, ItemDragEventArgs e)
        {
            if (!LoginUser.HasPermission(Privilege.BAS_StorageEdit)) return;
            TreeNode node = (TreeNode)e.Item;
            if (Function.GetStringValue(node.Tag) == "000") return;
            if (e.Button == MouseButtons.Left)
            {
                DoDragDrop(e.Item, DragDropEffects.Move);
            }
        }

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

        private void tvStorage_DragDrop(object sender, DragEventArgs e)
        {
            try
            {
                //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.tvStorage.GetNodeAt(pt);

                // 目标节点为空时，停止操作
                if (targeNode == null) return;
                // 去除本身拖放的情况
                if (targeNode == moveNode) return;
                // 防止拖放到自己的子级当中
                if (ChildJudge(targeNode, moveNode)) return;

                int index = moveNode.Tag.ToString().IndexOf(",");
                String StorageID = Function.GetStringValue(moveNode.Tag.ToString().Substring(0,index));
                String SuperStorageID = string.Empty;
                if (targeNode.Tag.ToString() == "000")
                {
                    SuperStorageID = Function.GetStringValue(targeNode.Tag);
                }
                else
                {
                    index = targeNode.Tag.ToString().IndexOf(",");
                    SuperStorageID = Function.GetStringValue(targeNode.Tag.ToString().Substring(0, index));
                }
                //更新“上级仓库编码”
                int iReturn = Services.BASService.UpdateSuperStorageByID(SuperStorageID, StorageID);
                if (iReturn == 1)
                {
                    LoadData();
                }
            }
            catch (Exception ex)
            {
                log.Error(Definition.MESSAGE_QUERY_ERROR + ":" + ex.Message);
                Tool.ShowMessage(Definition.MESSAGE_QUERY_ERROR + ":" + ex.Message,MessageBoxIcon.Error);
            }
        }
        #endregion

// 判断拖放项的子级中是否存有目标项

/// <summary>
        /// 判断拖放项的子级中是否存有目标项
        /// </summary>
        /// <param name="targeNode">目标项</param>
        /// <param name="modeNode">拖放项</param>
        /// <returns>true:有->停止操作，反之继续操作</returns>
        private bool ChildJudge(TreeNode targeNode, TreeNode modeNode)
        {
            foreach (TreeNode node in modeNode.Nodes)
            {
                if (node == targeNode)
                    return true;
                if (node.Nodes.Count > 0)
                    if (ChildJudge(targeNode, node))
                        return true;
            }
            return false;
        }