Treeview控件的用法

//treeview控件的用法，据我现在看，以下方法在winform中可行，在webform中不好用，有异常。
TreeNode vNode = new TreeNode("所有商品");  //定义一个名称为“所有商品”的节点
vNode.Nodes.Add("香烟类");            //在定义的“所有商品”下添加字节点
vNode.Nodes.Add("啤酒类");
vNode.Nodes.Add("食品类");
treeView1.Nodes.Add(vNode);          //在treeview中添加已定义好的节点
treeView1.ExpandAll();               //将treeview的所有节点展开
Treeview常常用SplitContainer分割接口，在”父窗体中停靠”等价于dock中的Fill。本身没有图片功能，需要与Imagelist一起使用。
//显示所有启动器名
private void TreeDemo_Load(object sender, EventArgs e)
        {
            //获得所有驱动器
            DriveInfo[] drives = DriveInfo.GetDrives();
            foreach (DriveInfo drive in drives)
            {
                DirectoryInfo root = drive.RootDirectory;
                TreeNode node = new TreeNode();
                node.Text = root.Name;
                node.Tag = root;
                treeView1.Nodes.Add(node);
                node.Nodes.Add(new TreeNode()); //显示加号，没有其他含义
node.ContextMenuStrip = this.contextmenustrip1; //节点弹出右键菜单，运行时，设计时的在属性中定义即可。
            }
        }

        private void treeView1_AfterExpand(object sender, TreeViewEventArgs e)
        {
            if (e.Action==TreeViewAction.Expand)
            {
                DirectoryInfo ParentFolder=(DirectoryInfo)e.Node.Tag;
                DirectoryInfo[] folders = ParentFolder.GetDirectories();
                e.Node.Nodes.Clear();
                foreach (DirectoryInfo folder in folders)
                {
                    TreeNode folderNode = new TreeNode();
                    folderNode.Text = folder.Name;
                    folderNode.Tag = folder;
                    e.Node.Nodes.Add(folderNode);
                    folderNode.Nodes.Add(new TreeNode());
folderNode.ContextMenuStrip = this.contextmenustrip2;
                }
            }
        }
TreeView在设置右键菜单时，设置节点的右键菜单，不要设置treeview的右键菜单。

nodes属性设置树节点 hideselection
TreeNode SelectNode = this.treeView1.SelectedNode; //确定选择的树形节点
            if (SelectNode != null)
            {
                SelectNode.Expand(); //显示树形目录的内容
            }
TreeNode SelectNode = this.treeView1.SelectedNode; //确定选择的树形节点
            if (SelectNode != null)
            {
                SelectNode.Collapse(); //隐藏树形目录的内容
            }
TreeNode SelectNode = this.treeView1.SelectedNode; //确定选择的树形节点
            if (SelectNode != null)
            {
                SelectNode.Toggle();//如果树形目录打开，就隐藏。如果隐藏，就打开树形目录。
            }
TreeNode SelectNode = this.treeView1.SelectedNode; //确定选择的树形节点
            if (SelectNode != null)
            {
                SelectNode.Nodes.Add(new TreeNode("新建文件夹"));//添加节点，虚拟添加，但未物理上添加
            }
TreeNode SelectNode = this.treeView1.SelectedNode; //确定选择的树形节点
            if (SelectNode != null)
            {
                SelectNode.Parent.Nodes.Remove(SelectNode);//删除节点，虚拟添加，未物理上删除。
            }
private void treeView1_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button==MouseButtons.Right)
            {
                TreeNode Node = treeView1.GetNodeAt(e.X, e.Y);  //取得节点的值
                if (Node!=null)
                {
                    this.treeView1.SelectedNode = Node;   //使右键和左键一样。
                }
            }
//web treeview
protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                InitTree(TreeView1.Nodes, "0");
            }
        }
        private void InitTree(TreeNodeCollection Nds, string parentId)
        {
            TreeNode tmpNd;
            string sql = "select * from TreeView";
            DataRow[] rows = SQLHelper.ExecuteDataset(sql).Tables[0].Select("ParentId=" + parentId);
            foreach (DataRow row in rows)
            {
                tmpNd = new TreeNode();
                tmpNd.Value = row["NodeId"].ToString();
                tmpNd.Text = row["NodeName"].ToString();
                tmpNd.NavigateUrl = row["Url"].ToString();
                Nds.Add(tmpNd);
                tmpNd.Expanded = false;//结点不展开。
                InitTree(tmpNd.ChildNodes, tmpNd.Value);
            }
        }