在线测试例子:http://vazumi.net.s1.kingidc.net/example/combobox.aspx 效果截图: 后台数据库是sql2k,一共一张表,3级联动是通过匹配code来搞 前台代码: %@ Page Language=C# AutoEventWireup=true CodeBehind=combobox.aspx.cs Inherits=test.example.combo

在线测试例子: http://vazumi.net.s1.kingidc.net/example/combobox.aspx

效果截图:

后台数据库是sql2k,一共一张表,3级联动是通过匹配code来搞

前台代码:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="combobox.aspx.cs" Inherits="test.example.combobox" %>





 
 
 
 
 
 
  
 
 

using System;
using System.Collections;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
using System.Data.Sql;
using System.Data.SqlClient;
using System.Configuration;

namespace test.service
{
 /// 

 /// $codebehindclassname$ 的摘要说明
 /// 
 [WebService(Namespace = "http://tempuri.org/")]
 [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]

 public class DataHandler : IHttpHandler
 {
 HttpContext Context;
 string json = "";

 public void ProcessRequest(HttpContext context)
 {
 Context = context;
 context.Response.ContentType = "text/plain";

 LoadDataToJSON();
 context.Response.Write(json);
 context.Response.End();
 }

 string GetQueryString(string name)
 {
 return Context.Request.Params[name];
 }

 string View
 {
 get { return Context.Request.QueryString["View"]; }
 }

 void LoadDataToJSON()
 {
 switch (View) //这里么写写sql语句，或者调存储过程
 {
 case "expstate": 
 GetNormalData("select id=min(code),text=state from city(nolock) group by state order by min(code)"); 
 break;
 case "expcity": 
 GetNormalData("select id=code,text=city from city(nolock) where left(code,2)='"+
 GetQueryString("stateid").Substring(0,2)+
 "' and right(code,2)='00' and right(code,4)<>'0000'"); 
 break;
 case "expsubcity": 
 GetNormalData("select id=code,text=city from city(nolock) where left(code,4)='" +
 GetQueryString("cityid").Substring(0,4) +"' and right(code,2)<>'00'"); break;
 }
 }

 void GetNormalData(string SQL) //SQL查询，返回json字符串，这个方法是普通的datatable转json
 {
 SqlConnection Conn = new SqlConnection(ConfigurationManager.ConnectionStrings["Conn"].ToString());
 SqlDataAdapter DA = new SqlDataAdapter(SQL, Conn);
 Conn.Open();
 DataSet DS = new DataSet();
 DA.Fill(DS, "c0");
 Conn.Close();
 string rs = JsonConvert.SerializeObject(DS.Tables["c0"], new DataTableConverter());
 json = rs;
 }