使用 AJAX 对全国地名进行选取

 

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
                      
      
                   <%--三个下拉列表--%>        
               
               
           
      

 

 

<%@ WebHandler Language="C#" Class="ccc" %>using System;using System.Web;using System.Linq;                 //**********using System.Collections.Generic;  //**********     三个引入的命名空间using System.Text;                  //**********public class ccc : IHttpHandler{    public void ProcessRequest(HttpContext context)    {        StringBuilder str = new StringBuilder();          str.Append("[");                           // 字符串拼接                            string s = context.Request["areacode"];        using (DataClassesDataContext con = new DataClassesDataContext())        {            List
      
        clist = new List
       
        ();            clist = con.ChinaStates.Where(r => r.ParentAreaCode ==s).ToList();            int count = 0;            foreach (ChinaStates c in clist)            {                if (count > 0)                {                    str.Append(",");                }                str.Append("{\"code\":\""+c.AreaCode +"\",\"name\":\""+c.AreaName+"\"}");                count++;          //将查询结果拼接成 json 对象！！！！！！！            }                    }        str.Append("]");        context.Response.Write(str);        context.Response.End();    }    public bool IsReusable    {        get        {            return false;        }    }}