上次的文章中说到在页面中异步调用WebServices中的方法，当然也可以异步调用aspx.cs中的静态方法。看下MSDN上的示例代码
CallAspxStaticMethod.aspx1
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="CallAspxStaticMethod.aspx.cs" Inherits="CallAspxStaticMethod" %>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>Using Page Methods with Session State</title>8
<style type="text/css">9
body 
{ font: 11pt Trebuchet MS;10
font-color: #000000;11
padding-top: 72px;12
text-align: center }13
.text { font: 8pt Trebuchet MS }14
</style>15
</head>16
<body>17
<form id="form1" runat="server">18
<asp:ScriptManager ID="ScriptManager1" 19
runat="server" EnablePageMethods="true">20
<Scripts>21
<asp:ScriptReference Path="JS/PageMethods.js"/>22
</Scripts>23
</asp:ScriptManager>24
</form>25
26
<center>27
<table>28
<tr align="left">29
<td>Write current date and time in session state:</td>30
<td>31
<input type="button" 32
onclick="SetSessionValue('SessionValue', Date())" 33
value="Write" />34
</td>35
</tr>36
<tr align="left">37
<td>Read current date and time from session state:</td>38
<td> 39
<input type="button" 40
onclick="GetSessionValue('SessionValue')" 41
value="Read" />42
</td>43
</tr>44
</table> 45
</center>46
47
<hr/>48
49
<span style="background-color:Aqua" id="ResultId"></span>50
</body>51
</html>52
在上面的代码中要注意一点，一定要将ScriptManager的EnablePageMethods属性设为true,这样才可以调用aspx.cs中的方法,ScriptManager下的ScriptReference属性是下面为异步调用写好的js函数
CallAspxStaticMethod.aspx.cs1
using System;2
using System.Collections.Generic;3
using System.Linq;4
using System.Web;5
using System.Web.UI;6
using System.Web.UI.WebControls;7
using System.Web.Services;8
9
public partial class CallAspxStaticMethod : System.Web.UI.Page10
{11
[WebMethod]12
// Get session state value.13
public static string GetSessionValue(string key)14
{15
return (string)HttpContext.Current.Session[key];16
}17
18
[WebMethod]19
// Set session state value.20
public static string SetSessionValue(string key, string value)21
{22
HttpContext.Current.Session[key] = value;23
return (string)HttpContext.Current.Session[key];24
}25
26
27
protected void Page_Load(object sender, EventArgs e)28
{29
30
}31
}32
在两个静态方法中要加上[WebMethod]属性。这样才可以被客户端js异步调用.
PageMethods.js1
// PageMethods.js2
3
var displayElement;4
5
// Initializes global variables and session state.6
function pageLoad() {7
displayElement = $get("ResultId");8
PageMethods.SetSessionValue("SessionValue", Date(),9
OnSucceeded, OnFailed);10
}11
12
// Gets the session state value.13
function GetSessionValue(key) {14
PageMethods.GetSessionValue(key,15
OnSucceeded, OnFailed);16
}17
18
//Sets the session state value.19
function SetSessionValue(key, value) {20
PageMethods.SetSessionValue(key, value,21
OnSucceeded, OnFailed);22
}23
24
// Callback function invoked on successful 25
// completion of the page method.26
function OnSucceeded(result, userContext, methodName) {27
if (methodName == "GetSessionValue") {28
displayElement.innerHTML = "Current session state value: " +29
result;30
}31
}32
33
// Callback function invoked on failure 34
// of the page method.35
function OnFailed(error, userContext, methodName) {36
if (error !== null) {37
displayElement.innerHTML = "An error occurred: " +38
error.get_message();39
}40
}41
42
if (typeof (Sys) !== "undefined") Sys.Application.notifyScriptLoaded();Code1
<script type="text/javascript">2
//<![CDATA[3
var PageMethods = function() {4
PageMethods.initializeBase(this);5
this._timeout = 0;6
this._userContext = null;7
this._succeeded = null;8
this._failed = null;9
}10
PageMethods.prototype = {11
_get_path:function() {12
var p = this.get_path();13
if (p) return p;14
else return PageMethods._staticInstance.get_path();},15
GetSessionValue:function(key,succeededCallback, failedCallback, userContext) {16
/// <param name="key" type="String">System.String</param>17
/// <param name="succeededCallback" type="Function" optional="true" mayBeNull="true"></param>18
/// <param name="failedCallback" type="Function" optional="true" mayBeNull="true"></param>19
/// <param name="userContext" optional="true" mayBeNull="true"></param>20
return this._invoke(this._get_path(), 'GetSessionValue',false,{key:key},succeededCallback,failedCallback,userContext); },21
SetSessionValue:function(key,value,succeededCallback, failedCallback, userContext) {22
/// <param name="key" type="String">System.String</param>23
/// <param name="value" type="String">System.String</param>24
/// <param name="succeededCallback" type="Function" optional="true" mayBeNull="true"></param>25
/// <param name="failedCallback" type="Function" optional="true" mayBeNull="true"></param>26
/// <param name="userContext" optional="true" mayBeNull="true"></param>27
return this._invoke(this._get_path(), 'SetSessionValue',false,{key:key,value:value},succeededCallback,failedCallback,userContext); }}28
PageMethods.registerClass('PageMethods',Sys.Net.WebServiceProxy);29
PageMethods._staticInstance = new PageMethods();30
PageMethods.set_path = function(value) {31
PageMethods._staticInstance.set_path(value); }32
PageMethods.get_path = function() { 33
/// <value type="String" mayBeNull="true">The service url.</value>34
return PageMethods._staticInstance.get_path();}35
PageMethods.set_timeout = function(value) {36
PageMethods._staticInstance.set_timeout(value); }37
PageMethods.get_timeout = function() { 38
/// <value type="Number">The service timeout.</value>39
return PageMethods._staticInstance.get_timeout(); }40
PageMethods.set_defaultUserContext = function(value) { 41
PageMethods._staticInstance.set_defaultUserContext(value); }42
PageMethods.get_defaultUserContext = function() { 43
/// <value mayBeNull="true">The service default user context.</value>44
return PageMethods._staticInstance.get_defaultUserContext(); }45
PageMethods.set_defaultSucceededCallback = function(value) { 46
PageMethods._staticInstance.set_defaultSucceededCallback(value); }47
PageMethods.get_defaultSucceededCallback = function() { 48
/// <value type="Function" mayBeNull="true">The service default succeeded callback.</value>49
return PageMethods._staticInstance.get_defaultSucceededCallback(); }50
PageMethods.set_defaultFailedCallback = function(value) { 51
PageMethods._staticInstance.set_defaultFailedCallback(value); }52
PageMethods.get_defaultFailedCallback = function() { 53
/// <value type="Function" mayBeNull="true">The service default failed callback.</value>54
return PageMethods._staticInstance.get_defaultFailedCallback(); }55
PageMethods.set_path("/Ajax/CallAspxStaticMethod.aspx");56
PageMethods.GetSessionValue= function(key,onSuccess,onFailed,userContext) {57
/// <param name="key" type="String">System.String</param>58
/// <param name="succeededCallback" type="Function" optional="true" mayBeNull="true"></param>59
/// <param name="failedCallback" type="Function" optional="true" mayBeNull="true"></param>60
/// <param name="userContext" optional="true" mayBeNull="true"></param>61
PageMethods._staticInstance.GetSessionValue(key,onSuccess,onFailed,userContext); }62
PageMethods.SetSessionValue= function(key,value,onSuccess,onFailed,userContext) {63
/// <param name="key" type="String">System.String</param>64
/// <param name="value" type="String">System.String</param>65
/// <param name="succeededCallback" type="Function" optional="true" mayBeNull="true"></param>66
/// <param name="failedCallback" type="Function" optional="true" mayBeNull="true"></param>67
/// <param name="userContext" optional="true" mayBeNull="true"></param>68
PageMethods._staticInstance.SetSessionValue(key,value,onSuccess,onFailed,userContext); }69
//]]>70
</script>71
在这里我们可以看到GetSessionValue:function(key,succeededCallback, failedCallback, userContext) 函数,在PageMethods.js中给他传入了相应的回调函数。