xmlHttp动态生成一张表

今天我想用xmlHttp来实现从数据库中读取一张表，然后显示到网页上。我首先会用三层架构来读取数据库中的数据，然后通过xml把数据传递该JavaScript的xmlHttp，在把数据显示到页面上。好，我们马上开始。
首先是建立数据库

CREATE TABLE [dbo].[MOA_Department](
 CREATE TABLE [dbo].[MOA_Department](
 [departmentId] [int] IDENTITY(1,1) NOT NULL,
 [departmentName] [nvarchar](50) NOT NULL,
 [parentDepartmentId] [int] NOT NULL,
 
 CONSTRAINT [PK_MOA_Department] PRIMARY KEY CLUSTERED
(
 [departmentId] ASC
)
)

还是我上一篇的数据库，具体不多说了，有疑问请参考我的上一篇“无线树”。

建立DB层

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;

namespace DB
{
    public class SqlHelper
    {
        private static string connStr = ConfigurationManager.ConnectionStrings["connStr"].ConnectionString.ToString();

        private static void pareComm(SqlConnection conn, SqlCommand comm, SqlParameter[] par, string sqlStr, CommandType type)
        {
            if (conn.State == ConnectionState.Closed)
            {
                conn.Open();
            }

            comm.Connection = conn;
            comm.CommandType = type;
            comm.CommandText = sqlStr;

            if (par != null)
            {
                foreach(SqlParameter p in par)
                {
                    comm.Parameters.Add(p);
                }
            }
        }

        public static SqlDataReader GetReader(string sqlStr, SqlParameter[] par)
        {
            SqlConnection conn = new SqlConnection(connStr);
            SqlCommand comm = new SqlCommand();

            pareComm(conn, comm, par, sqlStr, CommandType.Text);

            return comm.ExecuteReader(CommandBehavior.CloseConnection);
          
        }
    }
}

建立Model层

using System;
using System.Collections.Generic;
using System.Text;

namespace Model
{
    public class Department
    {
        private int departmentId;

        public int DepartmentId
        {
            get { return departmentId; }
            set { departmentId = value; }
        }

        private string departmentName;

        public string DepartmentName
        {
            get { return departmentName; }
            set { departmentName = value; }
        }

        private int parentDepartmentId;

        public int ParentDepartmentId
        {
            get { return parentDepartmentId; }
            set { parentDepartmentId = value; }
        }
    }
}

Model层的字段是跟数据表的字段一一对应的。

建立DAl数据访问层

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using Model;
using DB;

namespace DAL
{
    public class DepartmentDal
    {
        public List<Department> GetAllDepartment()
        {
            string sqlStr = "select departmentId,departmentName,parentDepartmentId from MOA_Department";
            List<Department> itemList = new List<Department>();

            SqlDataReader dr = SqlHelper.GetReader(sqlStr, null);

            while (dr.Read())
            {
                Department item = new Department();

                if (dr["departmentId"].ToString() != "")
                {
                    item.DepartmentId = Convert.ToInt32(dr["departmentId"].ToString());
                }

                if (dr["departmentName"] != null && dr["departmentName"].ToString() != string.Empty)
                {
                    item.DepartmentName = dr["departmentName"].ToString().Trim();
                }

                if (dr["parentDepartmentId"].ToString() != "")
                {
                    item.ParentDepartmentId = Convert.ToInt32(dr["parentDepartmentId"].ToString());
                }

                itemList.Add(item);
            }

            if (itemList.Count == 0)
            {
                dr.Close();
                return null;
            }
            else
            {
                dr.Close();
                return itemList;
            }

        }
    }
}

这里主要是获取数据表MOA_Department中的所有数据，存储在自定义实体类中，然后传递到BLL层中。

建立BLL层

using System;
using System.Collections.Generic;
using System.Text;
using Model;
using DAL;

namespace BLL
{
    public class DepartmentBll
    {
        public List<Department> GetAllDepartment()
        {
            DepartmentDal manager = new DepartmentDal();
            return manager.GetAllDepartment();  // 从DAL层获取数据
        }
    }
}

建立界面层，分别有两个网页和一个js文件。

首先建立一个从BLL层获取数据的页面，命名为：GetAllDepartment.aspx。页面是空白的，在页面的code-behind中编写一下代码：

using System;
using System.Configuration;
using System.Data;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Collections.Generic;
using BLL;
using Model;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            postAllDepartment();
        }
    }

    private void postAllDepartment()
    {
        DepartmentBll manager = new DepartmentBll();
        List<Department> itemList = new List<Department>();
        itemList = manager.GetAllDepartment();  // 从BLL层获取数据

        string responseText = "";  //初始化要传递的字符串
        responseText += "<response>";
        responseText += "<count>";
        responseText += itemList.Count;
        responseText += "</count>";

        foreach (Department item in itemList)
        {
            responseText += "<item>";
            responseText += "<departmentId>" + item.DepartmentId + "</departmentId>";
            responseText += "<departmentName>" + item.DepartmentName + "</departmentName>";
            responseText += "<parentDepartmentId>" + item.ParentDepartmentId + "</parentDepartmentId>";
            responseText += "</item>";
        }

        responseText += "</response>";

        Response.Clear();  // 清空response中的值
     
        Response.Expires = 0;  // 不使用缓存
        Response.ContentType = "text/xml";  // 声明传递的是xml
        Response.Write(responseText);  // 传递xml
        Response.End();  //结束传递
    }
}

建立JavaScript文件，新建目录js，在目录js下建立JavaScript文件JScript.js，输入以下代码：

var xmlHttp1;
    function createXmlHttpRequest()  // 新建xmlHttpRequest，根据浏览器来新建xmlHttpRequest
    {
        if(window.ActiveXObject)
        {
             xmlHttp1 = new ActiveXObject("Microsoft.XMLHTTP");
        }
        else if(window.XMLHttpRequest)
        {
             xmlHttp1 = new XMLHttpRequest();
        }
    }
   
    function getAllDepartment()
    {
         createXmlHttpRequest();
         var url = "GetAllDepartment.aspx";  // 初始化从哪个网页上获取数据
         xmlHttp1.open("GET",url,true)  // 打开连接，“GET”代表用什么方式来传递数据，这里使用get方式；ur是指从哪个网页上传递数据；true代表使用异步方式来传递数据。
         xmlHttp1.onreadystatechange = processRequest;  //回调函数
         xmlHttp1.send(null); //发送null
    }

   
    function processRequest()  //实现回调函数
    {
         if(xmlHttp1.readyState == 4)
         {
             if(xmlHttp1.status == 200)  //当回调成功及状态为200时输出数据
             {
                   var result = xmlHttp1.responseXML.getElementsByTagName("response")[0].getElementsByTagName("item"); //获取xml节点的值
                   var count = xmlHttp1.responseXML.getElementsByTagName("response")[0].getElementsByTagName("count");
                  
             
                   var divShow = document.getElementById("showDepartment");  //获取网页中要输出到哪个标签中
                  
                   divShow.innerHTML = "";  //清空标签中的值
 

                   var table = document.createElement("table");  //创建一个table标签
                   for(var i=0; i<count[0].firstChild.nodeValue; i++)
                   {
                          var tr = table.insertRow();  // 在表中插入一行
                          var td1 = tr.insertCell();   //  在行中插入一列
                          var td2 = tr.insertCell();
                          var td3 = tr.insertCell();
                          td1.innerHTML = result[i].getElementsByTagName("departmentId")[0].firstChild.nodeValue;  // 在列中插入数据
                          td2.innerHTML = result[i].getElementsByTagName("departmentName")[0].firstChild.nodeValue;
                          td3.innerHTML = result[i].getElementsByTagName("parentDepartmentId")[0].firstChild.nodeValue;
 
                   
                   }
 

                   divShow.appendChild(table);  //  把表添加到标签中
            
             }
         }
    }
   
   
 
getAllDepartment();

 建立显示数据的页面ShowAllDepartment.aspx，前台页面代码：

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ShowAllDepartment.aspx.cs" Inherits="ShowAllDepartment" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>无标题页</title>

    </head>
<body>
    <form id="form1" runat="server">
    <div id="showDepartment">
   
       
    </div>
    </form>
</body>
</html>
    <script type="text/javascript" language="javascript" src="js/JScript.js">
  
    </script>

编译运行，浏览ShowAllDepartment.aspx，则可以看到数据表显示在网页上