ajax连接数据库加载+三级联动

 1  <table id="tb1" style=" text-align: center; width: 100%;">
 2     <thead>
 3         <tr style="color: #ff6a00;">
 4             <td>用户名</td>
 5             <td>密码</td>
 6             <td>昵称</td>
 7             <td>性别</td>
 8             <td>生日</td>
 9             <td>年龄</td>
10             <td>民族</td>
11         </tr>
12     </thead>
13     <tbody>
14     </tbody>
15     </table>
16     <input type="button" value="加载" id="btn1" />

 1 <script>
 2     //点击加载按钮
 3     $("#btn1").click(function () {
 4         //编写ajax语句,将数据提交到某个服务端去
 5         $.ajax({
 6             url: "ajax/LoadUserajax.ashx",//将数据要提交到哪个服务端
 7             data: {},//将什么数据提交到服务端去,{}内基本格式为"key":"要传的数据"
 8             type: "post",//用什么样的方式将数据提交过去
 9             dataType: "json",//返回一个什么样的数据类型
10             //请求完成
11             success: function (data) {
12                 $("#tb1 tbody").empty();//清空tbody
13                 for (i in data) {
14                     var str = "<tr style=\"\">";
15                     str += "<td>" + data[i].username + "</td>";
16                     str += "<td>" + data[i].password + "</td>";
17                     str += "<td>" + data[i].nickname + "</td>";
18                     str += "<td>" + data[i].sex + "</td>";
19                     str += "<td>" + data[i].birthday + "</td>";
20                     str += "<td>" + data[i].age + "</td>";
21                     str += "<td>" + data[i].nation + "</td>";
22                     str += "</tr>";
23                     $("#tb1 tbody").append(str);
24                 }
25             },//success
26             //请求失败
27             error: function () {
28                 alert(‘服务器连接失败！！！‘);
29             }
30         });//ajax
31     });//btn1.click
32 </script>

 1 <%@ WebHandler Language="C#" Class="userajax" %>
 2 
 3 using System;
 4 using System.Web;
 5 using System.Collections;
 6 using System.Collections.Generic;
 7 using System.Linq;
 8 using System.Text;
 9 
10 public class userajax : IHttpHandler
11 {
12 
13     public void ProcessRequest(HttpContext context)
14     {
15         //有数据接收时，用context.Request["key"];将ajax传过来的数据取出来
16         int count = 0;//前面是否有数据
17         string end = "[";//创建json对象，设置默认值,基本格式为{"key":"value","":"","":""}，有多条时用[]括住，每条之间用,隔开
18         using (WebDataContext con = new WebDataContext())
19         {
20             List<User> ulist = con.User.ToList();
21             foreach (User u in ulist) {
22                 //前面有数据
23                 if (count>0) {
24                     end += ",";
25                 }
26                 end += "{\"username\":\""+u.UserName+"\",\"password\": \""+u.PassWord+"\",\"nicknane\":\""+u.NickName+"\",\"sex\": \""+u.SexStr+"\",\"birthday\": \""+u.BirStr+"\",\"age\":\""+u.Age+"\",\"nation\":\""+u.NationName+"\" }";
27                 count++;
28             }
29         }
30         end += "]";
31             context.Response.Write(end);
32             context.Response.End();
33      
34     }
35 
36     public bool IsReusable
37     {
38         get
39         {
40             return false;
41         }
42     }
43 
44 }

bind1($("#DropDownList1"), ‘0001‘, ‘1‘);
    function bind1(drop, pc, key) {
        $.ajax({
            url: "ajax/china.ashx",
            data: { "pcode": pc },
            type: "post",
            dataType: "json",
            success: function (data) {
                drop.empty();
                for (i in data) {
                    var str = "<option value=\"" + data[i].code + "\">" + data[i].name + "</option>";
                    drop.append(str);
                }
                if (key == "1")
                    {
                    bind1($("#DropDownList2"), $("#DropDownList1").val(), ‘2‘);
                }
                if (key == "2") {
                    bind1($("#DropDownList3"), $("#DropDownList2").val(), ‘3‘);
                }

            },
            error: function () {
                alert(‘服务器连接失败！‘);
            }
        });
    }
    $("#DropDownList1").change(function () {
        bind1($("#DropDownList2"), $(this).val(), ‘2‘);
    });

    $("#DropDownList2").change(function () {
        bind1($("#DropDownList3"), $(this).val(), ‘3‘);
    });

using System;
using System.Web;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
public class china : IHttpHandler {
    
    public void ProcessRequest (HttpContext context) {
        string pcode = context.Request["pcode"];
        StringBuilder end = new StringBuilder();
        int count = 0;

        end.Append("[");
        using (mydbDataContext con = new mydbDataContext())
        {
            List<ChinaStates> clist = con.ChinaStates.Where(r => r.ParentAreaCode == pcode).ToList();

            foreach (ChinaStates c in clist)
            {
                if (count > 0)
                    end.Append(",");
                
                end.Append("{\"code\":\""+c.AreaCode+"\",\"name\":\""+c.AreaName+"\"}");
                count++;
            }
        }

        end.Append("]");
        context.Response.Write(end);
        context.Response.End();
    }
 
    public bool IsReusable {
        get {
            return false;
        }
    }

}