一个用webservice behavior实现的三级联动下拉列表框

一个用webservice behavior实现的三级联动下拉列表框 

 
 
 
 我做了一个三级联动的下拉列表框，后台用webservice,前台用webservice behavior与后台通讯。请高手们多提改进意见。

server端：（service1.asmx.cs)

using System;
using System.Text;
using System.Configuration;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Diagnostics;
using System.Web;
using System.Web.Services;

namespace WebService1
...{
    /**//// <summary>
    /// Summary description for Service1.
    /// </summary>
    public class Service1 : System.Web.Services.WebService
    ...{
        SqlConnection con;
        

        public Service1()
        ...{
            //CODEGEN: This call is required by the ASP.NET Web Services Designer
            InitializeComponent();
        }

        Component Designer generated code#region Component Designer generated code
        /**//// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        ...{
            string dsn = ConfigurationSettings.AppSettings["yitong"];

            con=new SqlConnection(dsn);
        }
        #endregion

        /**//// <summary>
        /// Clean up any resources being used.
        /// </summary>
        protected override void Dispose( bool disposing )
        ...{
        }


        [WebMethod]
        public string fenlei()
        ...{
            string str="select distinct substring(code,1,3) as fenlei from jinan ";
            SqlCommand cmd=new SqlCommand(str,con);            

            cmd.Connection.Open();
            SqlDataReader dr=cmd.ExecuteReader();
            

            string s="请选择：";
            while(dr.Read())
            ...{
                s += ","+dr["fenlei"].ToString();
            }
            return s;
        }

        [WebMethod]
        public string leixing(string q)
        ...{
            
            string str="select distinct type from jinan where code like '"+q+"%'";
            SqlCommand cmd=new SqlCommand(str,con);            

            cmd.Connection.Open();
            SqlDataReader dr=cmd.ExecuteReader();
            

            string s="请选择：";
            while(dr.Read())
            ...{
                s += ","+dr["type"].ToString();
            }
            return s;
        }


        [WebMethod]
        public string haoduan(string q)
        ...{
            string str="select distinct substring(code,4,4) as haoduan from jinan where type='"+q+"'";
            SqlCommand cmd=new SqlCommand(str,con);            

            cmd.Connection.Open();
            SqlDataReader dr=cmd.ExecuteReader();
            

            string s="请选择：";
            while(dr.Read())
            ...{
                s += ","+dr["type"].ToString();
            }
            return s;
        }




client端(htmlpage1.htm)
 

 

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
    <HEAD>
        <META NAME="GENERATOR" Content="Microsoft Visual Studio 7.0">
        <TITLE></TITLE>
        <script id="clientEventHandlersJS" language="javascript">...
<!--
var icallid;
var icallid1;
var icallid2;

function window_onload() ...{
service.useService("/service1.asmx?WSDL","myselect");

icallid=service.myselect.callService(fenlei,"fenlei");

}

function fenlei(result)
...{
var m=result.value;
var a=m.split(",")

for(var i=0;i<a.length;i++)
...{
window.s1.options[i]=new Option(a[i],a[i]);
}
}

function s1_onchange() ...{
var x=s1.value;
icallid1=service.myselect.callService(leixing,"leixing",x);
}

function s2_onchange() ...{
var x=s2.value;
icallid2=service.myselect.callService(haoduan,"haoduan",x);
}

function leixing(result)...{
var m=result.value;
var a=m.split(",")

window.s2.length=0;

for(var i=0;i<a.length;i++)
...{
window.s2.options[i]=new Option(a[i],a[i]);
}
}

function haoduan(result)...{
var m=result.value;
var a=m.split(",")

window.s3.length=0;

for(var i=0;i<a.length;i++)
...{
window.s3.options[i]=new Option(a[i],a[i]);
}

}

//-->
        </script>
    </HEAD>
    <BODY onload="return window_onload()">
        <div id="service" style="behavior:url(webservice.htc)">
        </div>
        <select id="s1" onchange="return s1_onchange()"> </select><select id="s2" onchange="return s2_onchange()"></select>
        <select id="s3"></select>
</HTML>