private void treeView_ItemDrag(object sender, System.Windows.Forms.ItemDragEventArgs e)
        {
            DoDragDrop(e.Item, DragDropEffects.Move); 
        }

        private void treeView_DragEnter(object sender, System.Windows.Forms.DragEventArgs e)
        {
         e.Effect = DragDropEffects.Move;
        }

        private void treeView_DragDrop(object sender, System.Windows.Forms.DragEventArgs e)
        {
            TreeNode NewNode; 
            if(e.Data.GetDataPresent("System.Windows.Forms.TreeNode", false)) 
            {
                Point pt = ((TreeView)sender).PointToClient(new Point(e.X, e.Y));
                TreeNode DestinationNode = ((TreeView)sender).GetNodeAt(pt); 
                NewNode = (TreeNode)e.Data.GetData("System.Windows.Forms.TreeNode"); 
                if(DestinationNode.TreeView != NewNode.TreeView) 
                {
                    DestinationNode.Nodes.Add((TreeNode) NewNode.Clone());
                    DestinationNode.Expand(); 
                } 
            } 
        }

private void my1_Load(object sender, System.EventArgs e)
        {        
            TreeNode ParentNode1; 
            TreeNode ParentNode2; 
            ParentNode1 = treeView1.Nodes.Add("WTS"); 
            ParentNode2.Tag = "";
            ParentNode1.Nodes.Add("WTS1"); 
            ParentNode1.Nodes[0].Tag = "";
            ParentNode1.Nodes.Add("WTS2");    
            ParentNode1.Nodes[1].Tag = "";
            ParentNode1.Expand(); 
            ParentNode2 = treeView2.Nodes.Add("wts");
            ParentNode2.Tag = "";
            ParentNode2.Nodes.Add("wts1"); 
            ParentNode2.Nodes[0].Tag = "";
            ParentNode2.Nodes.Add("wts2"); 
            ParentNode2.Nodes[1].Tag = "";
            ParentNode2.Expand(); 
            this.treeView1.ItemDrag += new System.Windows.Forms.ItemDragEventHandler(this.treeView_ItemDrag); 
            this.treeView2.ItemDrag += new System.Windows.Forms.ItemDragEventHandler(this.treeView_ItemDrag); 
            this.treeView1.DragEnter += new System.Windows.Forms.DragEventHandler(this.treeView_DragEnter); 
            this.treeView2.DragEnter += new System.Windows.Forms.DragEventHandler(this.treeView_DragEnter); 
            this.treeView1.DragDrop += new System.Windows.Forms.DragEventHandler(this.treeView_DragDrop); 
            this.treeView2.DragDrop += new System.Windows.Forms.DragEventHandler(this.treeView_DragDrop); 
        }

创建根节点#region 创建根节点
        private TreeNode CreateNewNode()
        {
            TreeNode node = new TreeNode(this.txtTitle.Text.Trim());
            node.Tag = "";
            return node;
        }
        #endregion 
        从XML中得到数据#region 从XML中得到数据
        private void GetDataFromXML ()
        {
            //从XML中读取数据到TreeView            
            try
            {
                XmlDocument xmlDoc = new XmlDocument();
                xmlDoc.Load("Menu.xml");

                XmlNodeList xmlNodes = xmlDoc.DocumentElement.ChildNodes;

                this.treeView1.BeginUpdate();
                this.treeView1.Nodes.Clear();
                XmlNodeToTreeNode(xmlNodes, this.treeView1.Nodes);
                this.treeView1.EndUpdate();
            }
            catch
            {
            }
            
        }
        #endregion 
        向XML中写数据#region 向XML中写数据
        private void InsertDataIntoXML ()
        {
            //将TreeView保存到XML文件中            
            XmlDocument doc = new XmlDocument();
            doc.LoadXml("<Menu></Menu>");
            XmlNode root = doc.DocumentElement;
            doc.InsertBefore(doc.CreateXmlDeclaration("1.0", "utf-8", "yes"), root);
            TreeNodeToXml(this.treeView1.Nodes, root);
            doc.Save("Menu.xml");
        }
        #endregion 
        TreeNodeToXml#region TreeNodeToXml
        private void TreeNodeToXml(TreeNodeCollection treeNodes, XmlNode xmlNode)
        {
            XmlDocument doc = xmlNode.OwnerDocument;
            foreach (TreeNode treeNode in treeNodes)
            {
                XmlNode element = doc.CreateNode("element", "Item", "");
                XmlAttribute attr = doc.CreateAttribute("WTS");
                treeNode.Tag ="";
                attr.Value = treeNode.Text;
                element.Attributes.Append(attr);
                element.AppendChild(doc.CreateCDataSection(treeNode.Tag.ToString()));
                xmlNode.AppendChild(element);

                if (treeNode.Nodes.Count > 0)
                {
                    TreeNodeToXml(treeNode.Nodes, element);
                }
            }
        }
        #endregion 
        XmlNodeToTreeNode#region XmlNodeToTreeNode
        private void XmlNodeToTreeNode(XmlNodeList xmlNode, TreeNodeCollection treeNode)
        {
            foreach (XmlNode var in xmlNode)
            {
                if (var.NodeType != XmlNodeType.Element)
                {
                    continue;
                }
                TreeNode newTreeNode = new TreeNode();
                newTreeNode.Text = var.Attributes["WTS"].Value;            
                if (var.HasChildNodes)
                {
                    if (var.ChildNodes[0].NodeType == XmlNodeType.CDATA)
                    {
                        newTreeNode.Tag = var.ChildNodes[0].Value;
                    }

                    XmlNodeToTreeNode(var.ChildNodes, newTreeNode.Nodes);
                }
                treeNode.Add(newTreeNode);
            }
        }
        #endregion XmlNodeToTreeNode