onreadystatechange 指定当readyState属性改变时的事件处理
readystate 返回当前请求的状态
responseBody 以unsigned byte数组形式返回
responseStream 以Ado Stream对象的形式返回
responseText 作为字符串返回
responseXML 将响应的信息格式为Xml Document对象返回
status 当前请求的HTTP状态码
statusText 返回当前请求的响应行状态
XMLHttpRequest对象的方法:
abort
getAllResponseHeaders
getResponseHeader
open
send
setRequestHeader
===========================================================
下面是一个完整的实例
===========================================================
ajax_service.cs (webService文件Ajax_Service.asmx的后台)
1
using System;
2using System.Web;
3using System.Collections;
4using System.Web.Services;
5using System.Web.Services.Protocols;
6
7
8
/// <summary>
9
/// Ajax_Service 的摘要说明
10
/// </summary>
11[WebService(Namespace = "http://tempuri.org/")]
12[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
13public class Ajax_Service : System.Web.Services.WebService {
14
15
public Ajax_Service () {
16
17 //如果使用设计的组件，请取消注释以下行
18 //InitializeComponent();
19
}
20
21 [WebMethod]
22 public string HelloWorld() {
23 return "Hello World";
24 }
25
26
27 /*
28 返回a+b的和
29 */
30 [WebMethod]
31 public int Sum(int a,int b)
32 {
33 return a + b;
34 }
35
36}
37
38
using System;2
using System.Web;3
using System.Collections;4
using System.Web.Services;5
using System.Web.Services.Protocols;6
7
8
/// <summary>
9
/// Ajax_Service 的摘要说明10
/// </summary>11
[WebService(Namespace = "http://tempuri.org/")]12
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]13
public class Ajax_Service : System.Web.Services.WebService {
14
15
public Ajax_Service () {
16
17
//如果使用设计的组件，请取消注释以下行 18
//InitializeComponent(); 19
}20
21
[WebMethod]22
public string HelloWorld() {23
return "Hello World";24
}25
26
27
/*28
返回a+b的和29
*/30
[WebMethod]31
public int Sum(int a,int b)32
{33
return a + b;34
}35
36
}37
38
前台文件:Ajax_Service.aspx
1<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Ajax_Service.aspx.cs" Inherits="Ajax_Service" %>
2
3<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
4
5<html xmlns="http://www.w3.org/1999/xhtml" >
6<head runat="server">
7 <title>Ajax_WebService</title>
8
9 <script type="text/javascript">
10
11 var xmlhttp;
12
13 function createXmlhttp()
14 {
15 if(window.XMLHttpRequest)
16 {
17 xmlhttp = new XMLHttpRequest();
18 }
19 else if(window.ActiveXObject)
20 {
21 try
22 {
23 xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
24 }
25 catch(e)
26 {
27 xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
28 }
29 }
30
31 if(!xmlhttp)
32 {
33 alert('您的浏览器不支持XMLHttpRequest');
34 }
35 return xmlhttp;
36 }
37
38 function SumIt()
39 {
40 createXmlhttp();
41 var url = "http://localhost:8051/Ajax_Service.asmx/Sum";
42 var queryString = createQueryString();
43 xmlhttp.open("POST",url,true);
44 xmlhttp.onreadystatechange = handleStateChange;
45 xmlhttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded;");
46 xmlhttp.send(queryString);
47 }
48
49
50 function createQueryString()
51 {
52 var a = document.getElementById('txbA').value;
53 var b = document.getElementById('txbB').value;
54 var queryString = 'a='+a+'&b='+b;
55 return queryString;
56 }
57
58 function handleStateChange()
59 {
60 if(xmlhttp.readyState == 4)
61 {
62 if(xmlhttp.status == 200)
63 {
64 displayResult();
65 }
66 }
67 }
68
69 function displayResult()
70 {
71 var result = document.getElementById('lblResult');
72 result.innerText = '计算结果:' + xmlhttp.responseXML.getElementsByTagName('int')[0].firstChild.data;
73
74 }
75
76 </script>
77
78</head>
79<body>
80 <form id="form1" runat="server">
81 <div>
82
83 <input type="text" id="txbA" />
84 <input type="text" id="txbB" />
85 <input type="button" id="btm" value="计算" onclick="SumIt();" />
86
87 <label id="lblResult"></label>
88 </div>
89 </form>
90</body>
91</html>
92
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Ajax_Service.aspx.cs" Inherits="Ajax_Service" %>2
3
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">4
5
<html xmlns="http://www.w3.org/1999/xhtml" >6
<head runat="server">7
<title>Ajax_WebService</title>8
9
<script type="text/javascript">10
11
var xmlhttp;12
13
function createXmlhttp()14
{15
if(window.XMLHttpRequest)16
{17
xmlhttp = new XMLHttpRequest();18
}19
else if(window.ActiveXObject)20
{21
try22
{23
xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");24
}25
catch(e)26
{27
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");28
}29
}30
31
if(!xmlhttp)32
{33
alert('您的浏览器不支持XMLHttpRequest');34
}35
return xmlhttp; 36
}37
38
function SumIt()39
{40
createXmlhttp();41
var url = "http://localhost:8051/Ajax_Service.asmx/Sum";42
var queryString = createQueryString();43
xmlhttp.open("POST",url,true);44
xmlhttp.onreadystatechange = handleStateChange;45
xmlhttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded;");46
xmlhttp.send(queryString);47
}48
49
50
function createQueryString()51
{52
var a = document.getElementById('txbA').value;53
var b = document.getElementById('txbB').value;54
var queryString = 'a='+a+'&b='+b;55
return queryString;56
}57
58
function handleStateChange()59
{60
if(xmlhttp.readyState == 4)61
{62
if(xmlhttp.status == 200)63
{64
displayResult();65
}66
}67
}68
69
function displayResult()70
{71
var result = document.getElementById('lblResult');72
result.innerText = '计算结果:' + xmlhttp.responseXML.getElementsByTagName('int')[0].firstChild.data;73
74
}75
76
</script>77
78
</head>79
<body>80
<form id="form1" runat="server">81
<div>82
83
<input type="text" id="txbA" />84
<input type="text" id="txbB" />85
<input type="button" id="btm" value="计算" onclick="SumIt();" />86
87
<label id="lblResult"></label> 88
</div>89
</form>90
</body>91
</html>92