(转) treeview 的设计思路

 

数据库设计

首先，我们在SQL SERVER 2000里建立一个表tbTree，表的结构设计如下：

列名	数据类型	描述	长度	主键
ID	Int	节点编号	4	是
ParentID	Int	父节点编号	4
ConText	Nvarchar	我们要显示的节点内容	50

在SQL SERVER 2000中建表的脚本：

CREATE TABLE [dbo].[tbTree] (

       [ID] [int] IDENTITY (1, 1) NOT NULL ,

       [Context] [nvarchar] (50) COLLATE Chinese_PRC_CI_AS NULL ,

       [ParentID] [int] NULL

) ON [PRIMARY]

 

在表中添加如下记录：

SET IDENTITY_INSERT tbtree ON

insert tbtree (ID,Context,ParentID) values ( 1,'中国',0)

insert tbtree (ID,Context,ParentID) values ( 2,'北京',1)

insert tbtree (ID,Context,ParentID) values ( 3,'天津',1)

insert tbtree (ID,Context,ParentID) values ( 4,'河北省',1)

insert tbtree (ID,Context,ParentID) values ( 5,'广东省',1)

insert tbtree (ID,Context,ParentID) values ( 6,'广州',5)

insert tbtree (ID,Context,ParentID) values ( 7,'四川省',1)

insert tbtree (ID,Context,ParentID) values ( 8,'成都',7)

insert tbtree (ID,Context,ParentID) values ( 9,'深圳',5)

insert tbtree (ID,Context,ParentID) values ( 10,'石家庄',4)

insert tbtree (ID,Context,ParentID) values ( 11,'辽宁省',1)

insert tbtree (ID,Context,ParentID) values ( 12,'大连',11)

insert tbtree (ID,Context,ParentID) values ( 13,'上海',1)

insert tbtree (ID,Context,ParentID) values ( 14,'天河软件园',6)

insert tbtree (ID,Context,ParentID) values ( 15,'汕头',5)

SET IDENTITY_INSERT tbtree off

下载Treeview控件地址

http://msdn.microsoft.com/downloads/samples/internet/ASP_DOT_NET_ServerControls/WebControls/default.asp

安装后，通过“自定义工具箱”->“.net框架组件”把TreeView添加到工具箱里。

新建一个项目，在页面上拖画一个TreeView控件。

namespace TreeCS

{

       /// <summary>

       /// WebForm1 的摘要说明

       /// </summary>

       public class WebForm1 : System.Web.UI.Page

       {

              protected Microsoft.Web.UI.WebControls.TreeView TreeView1;

      

              private void Page_Load(object sender, System.EventArgs e)

              {

                     // 定义数据库连接

                     SqlConnection CN = new SqlConnection();

                     try

                     {

                            //初始化连接字符串

                            CN.ConnectionString= "data source=pmserver;initial catalog=Benchmark;persist security info=False;user id=sa;Password=;";

                            CN.Open();

 

                            SqlDataAdapter adp = new SqlDataAdapter("select * from tbTree",CN);

                            DataSet ds=new DataSet();

                            adp.Fill(ds);

                            this.ViewState["ds"]=ds;

                     }

                     catch (Exception ex)

                     {

                            Session["Error"] = ex.ToString();

                            Response.Redirect("error.aspx");       //̀跳转程序的公共错误处理页面

                     }

                     finally

                     {

                            CN.Close();

                     }

                     //调用递归函数，完成树形结构的生成

                     AddTree(0, (TreeNode)null);

              }

 

              //递归添加树的节点

              public void AddTree(int ParentID,TreeNode pNode)

              {

                     DataSet ds=(DataSet) this.ViewState["ds"];

                     DataView dvTree = new DataView(ds.Tables[0]);

                     //过滤ParentID,得到当前的所有子节点

                     dvTree.RowFilter =  "[PARENTID] = " + ParentID;

 

                     foreach(DataRowView Row in dvTree)

                     {

                            TreeNode Node=new TreeNode() ;

                            if(pNode == null)

                            {    //添加根节点

                                   Node.Text = Row["ConText"].ToString();

                                   TreeView1.Nodes.Add(Node);

                                   Node.Expanded=true;

                                   AddTree(Int32.Parse(Row["ID"].ToString()), Node);    //再次递归

                            }

                            else

                            {   //̀添加当前节点的子节点

                                   Node.Text = Row["ConText"].ToString();

                                   pNode.Nodes.Add(Node);

                                   Node.Expanded = true;

                                   AddTree(Int32.Parse(Row["ID"].ToString()),Node);     //再次递归

                            }

                     }                  

              }           

 

              #region Web Form Designer generated code

              override protected void OnInit(EventArgs e)

              {

                     //

                     // CODEGEN该调用是 ASP.NET Web 窗体设计器所必需的。

                     //

                     InitializeComponent();

                     base.OnInit(e);

              }

             

              /// <summary>

              ///设计器支持所需的方法 - 不要使用代码编辑器修改

              /// 此方法的内容

              /// </summary>

              private void InitializeComponent()

              {   

                     this.Load += new System.EventHandler(this.Page_Load);

 

              }

              #endregion

       }

}