web| Dropdown | dropdown list I did a three-level linkage drop-down list box, the background with WebService, the foreground with WebService behavior and background communication. Please make more suggestions to improve the experts.
Server end: (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 are required by the ASP.net Web Services Designer
InitializeComponent ();
}
#region Component Designer generated code
<summary>
Required to Designer support-do not modify
The contents is with the Code Editor.
</summary>
private void InitializeComponent ()
{
String DSN = configurationsettings.appsettings["Yitong"];
Con=new SqlConnection (DSN);
}
#endregion
<summary>
Clean up any 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= "Please select:";
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= "Please select:";
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= "Please select:";
while (Dr. Read ())
{
s = = "," +dr["type"]. ToString ();
}
return s;
}
Client Side (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>
