要想实现JS调用WebService,可以按如下步骤实现(经过测试)：
第一步：创建一个WebService
在此处我就创建了一个默认的web服务，并不做什么修改，把主要集力放在怎么实现JS调Web服务上面。
代码
using System;
using System.Collections.Generic;
using System.Web;
using System.Web.Services;
// / <summary>
// /WebService 的摘要说明
// / </summary>
[WebService(Namespace = " http://tempuri.org/ " )]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
public class WebService : System.Web.Services.WebService
{
public WebService()
{
// 如果使用设计的组件，请取消注释以下行
// InitializeComponent();
}
[WebMethod]
public string HelloWorld()
{
return " Hellow World " ;
}
}
第二步：创建一个页面，实现JS调用Web服务
代码
<% @ Page Language = " C# " AutoEventWireup = " true " CodeFile = " Default3.aspx.cs " Inherits = " Default3 " %>
<! DOCTYPE html PUBLIC " -//W3C//DTD XHTML 1.0 Transitional//EN " " http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd " >
< html xmlns = " http://www.w3.org/1999/xhtml " >
< head runat = " server " >
< title >< / title>
< script type = " text/javascript " >
function RequestWebService() {
// 这是我们在第一步中创建的Web服务的地址
var URL = " http://localhost/YBWS/WebService.asmx " ;
// 在这处我们拼接
var data;
data = ' <?xml version="1.0" encoding="utf-8"?> ' ;
data = data + ' <soap12:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap12="http://www.w3.org/2003/05/soap-envelope"> ' ;
data = data + ' <soap12:Body> ' ;
data = data + ' <HelloWorld xmlns="http://tempuri.org/" /> ' ;
data = data + ' </soap12:Body> ' ;
data = data + ' </soap12:Envelope> ' ;
// 创建异步对象
var xmlhttp = new ActiveXObject( " Microsoft.XMLHTTP " );
xmlhttp.Open( " POST " , URL, false );
xmlhttp.SetRequestHeader( " Content-Type " , " application/soap+xml " );
xmlhttp.Send(data);
document.getElementById( " data " ).innerHTML = xmlhttp.responseText;
}
< / script>
< / head>
< body >
< form id = " form1 " runat = " server " >
< div >
< input id = " One " type = " button " value = " JsCallWebService " onclick = " RequestWebService() " / >
< / div>
< div id = " data " >
< / div>
< / form>
< / body>
< / html>
当点击按钮时，效果如下图：
