我以一個最簡單的helloworld為例，示範AJax.net源碼中調用背景服務的機制，隻是列出一些大體的架構，具體細節我還在研究中:)
不當之處，歡迎指正。
我先把例子中的核心代碼列出，友善大家閱讀。
HelloWorldService服務中：
[WebMethod(EnableSession = true)]
public string HelloWorld(string name)
{
String aaa = Session["name"].ToString();
string hello = String.IsNullOrEmpty(name) ? "無名氏" : name;
hello += "你好,目前伺服器時間是：";
hello += DateTime.Now.ToUniversalTime() + " " + aaa;
return hello;
}
HelloWorld.aspx檔案:
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="HelloWorld.aspx.cs" Inherits="_Default" %>
<%@ Register Assembly="Microsoft.Web.Extensions" Namespace="Microsoft.Web.UI" TagPrefix="asp" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head id="Head1" runat="server">
<title>Hello</title>
<script type="text/javascript">
function SayHello()
var fs = HelloWorldService;
fs.set_defaultSucceededCallback(OnShow);
fs.HelloWorld(document.getElementById("name").value);
function OnShow(result)
var s = document.getElementById("result");
s.innerText = result;
</script>
</head>
<body style="font-size: 12pt">
<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server">
<Services>
<asp:ServiceReference Path="~/HelloWorldService.asmx" />
</Services>
</asp:ScriptManager>
<div>
你的名字:
<input type="text" maxlength="20" id="name" />
<input type="button" id="button1" value="問候" onclick="SayHello()" />
<div id="result"></div>
</div>
</form>
</body>
</html>
背景調用機制分析：(都是Microsoft.Web.Extensions.dll反編譯後看到的)
1、在AssemblyInfo.cs中聲明了如下一些javascript腳本：
[assembly: System.Web.UI.WebResource("Microsoft.Web.Resources.Timer.bmp", "image/bmp")]
[assembly: System.Web.UI.WebResource("Microsoft.Web.Resources.Background.gif", "image/gif")]
[assembly: System.Web.UI.WebResource("Microsoft.Web.Resources.ScriptLibrary.MicrosoftAjaxWebForms.debug.js", "application/x-javascript")]
[assembly: System.Web.UI.WebResource("Microsoft.Web.Resources.ScriptLibrary.MicrosoftAjaxRuntime.debug.js", "application/x-javascript")]
[assembly: System.Web.UI.WebResource("Microsoft.Web.Resources.ScriptLibrary.MicrosoftAjax.debug.js", "application/x-javascript")]
[assembly: System.Web.UI.WebResource("Microsoft.Web.Resources.ScriptLibrary.MicrosoftAjaxWebForms.js", "application/x-javascript")]
[assembly: System.Web.UI.WebResource("Microsoft.Web.Resources.ScriptLibrary.MicrosoftAjaxRuntime.js", "application/x-javascript")]
[assembly: System.Web.UI.WebResource("Microsoft.Web.Resources.ScriptLibrary.MicrosoftAjax.js", "application/x-javascript")]
這些javascript腳本也都是作為資源包含在Microsoft.Web.Extensions.dll中的
2、在ScriptManager的OnPreRender中進行如下操作，進行js代碼的注冊(有的方法是調用其它類裡面的)：
//取得AJax的用戶端腳本名稱
private static string GetFullName(string name, System.Reflection.Assembly assembly)
{
if (assembly != ScriptReference.AtlasFrameworkAssembly)
{
return name;
}
return ("Microsoft.Web.Resources.ScriptLibrary." + name);
}
//取得dll中js檔案的位置
string IClientScriptManager.GetWebResourceUrl(Type type, string resourceName)
return this._clientScriptManager.GetWebResourceUrl(type, resourceName);
}
//注冊客戶段腳本(寫入頁面的html檔案中去)
void IClientScriptManager.RegisterClientScriptInclude(Type type, string key, string url)
this._clientScriptManager.RegisterClientScriptInclude(type, key, url);
//注冊服務
//取得頁面上有哪些服務，如上面的HelloWorldService.asmx服務,然後調用如下語句
this._clientScriptManager.RegisterClientScriptInclude(type, "HelloWorldService.asmx/jsdebug", "HelloWorldService.asmx/jsdebug");
以上主要是使用.net 2.0新增的ClientScriptManager類進行用戶端腳本的注冊，也就是生成我們在頁面上看到的如下一段代碼：
(通過檢視運作時的aspx檔案的html代碼)
<script src="/Web/WebResource.axd?d=7lZSau3voGpyPgiEEMwJxQ2&amp;t=632965017419375000" type="text/javascript"></script>
......
<script src="/Web/WebResource.axd?d=VbevhO3ptb2WYvwQWrgTHKAWH4jfDIInCsIvYHSSJgRDZKhi9uLV9U_0kyOUMuNB32yLgf_UUzCml8vnGl7OI4r89qpFWhjBi2BmMZGBkApjwmG5MAGWzA_yjFYvRA8w2gdgDWR5RgcQF-F7MVigcyaKFVde2W9oIqW8P4zdL9g1&amp;t=632985966674218750" type="text/javascript"></script>
<script src="HelloWorldService.asmx/jsdebug" type="text/javascript"></script>
3、通過IHttpHandlerFactory接口對服務進行處理：
在web.config中進行注冊：
<httpHandlers>
<remove verb="*" path="*.asmx"/>
<add verb="*" path="*.asmx" validate="false" type="Microsoft.Web.Script.Services.ScriptHandlerFactory, Microsoft.Web.Extensions"/>
</httpHandlers>
然後在ScriptHandlerFactory中調用如下一段代碼：
public void ProcessRequest(HttpContext context)
this._originalHandler.ProcessRequest(context);
base._builder.Append(text1).Append(".set_path = function(value) { \r\n/// <summary>Sets the service url.</summary>\r\n/// <param name=\"path\" type=\"String\">The service url.\r\nvar e = Function._validateParams(arguments, [{name: 'path', type: String}]); if (e) throw e; ").Append(text1).Append("._staticInstance._path = value; }\r\n");
base._builder.Append(text1).Append(".get_path = function() { \r\n/// <summary>Returns the service url.</summary>\r\n/// <returns type=\"String\">The service url.</returns>\r\nreturn ").Append(text1).Append("._staticInstance._path; }\r\n");
base._builder.Append(text1).Append(".set_timeout = function(value) { \r\n/// <summary>Sets the service timeout.</summary>\r\n/// <param name=\"value\" type=\"Number\">The service timeout.\r\nvar e = Function._validateParams(arguments, [{name: 'timeout', type: Number}]); if (e) throw e; if (value < 0) { throw Error.argumentOutOfRange('value', value, Sys.Res.invalidTimeout); }\r\n").Append(text1).Append("._staticInstance._timeout = value; }\r\n");
base._builder.Append(text1).Append(".get_timeout = function() { \r\n/// <summary>Returns the service timeout.</summary>\r\n/// <returns type=\"Number\">The service timeout.</returns>\r\nreturn ").Append(text1).Append("._staticInstance._timeout; }\r\n");
base._builder.Append(text1).Append(".set_defaultUserContext = function(value) { \r\n/// <summary>Sets the service default userContext.</summary>\r\n/// <param name=\"value\">The service default user context.\r\n").Append(text1).Append("._staticInstance._userContext = value; }\r\n");
base._builder.Append(text1).Append(".get_defaultUserContext = function() { \r\n/// <summary>Returns the service default user context.</summary>\r\n/// <returns>The service default user context.</returns>\r\nreturn ").Append(text1).Append("._staticInstance._userContext; }\r\n");
base._builder.Append(text1).Append(".set_defaultSucceededCallback = function(value) { \r\n/// <summary>Sets the service default succeeded callback.</summary>\r\n/// <param name=\"value\" type=\"Function\">The service default succeed callback function.\r\nvar e = Function._validateParams(arguments, [{name: 'defaultSucceededCallback', type: Function}]); if (e) throw e; ").Append(text1).Append("._staticInstance._succeeded = value; }\r\n");
base._builder.Append(text1).Append(".get_defaultSucceededCallback = function() { \r\n/// <summary>Returns the service default succeeded callback.</summary>\r\n/// <returns type=\"Function\">The service default succeeded callback.</returns>\r\nreturn ").Append(text1).Append("._staticInstance._succeeded; }\r\n");
base._builder.Append(text1).Append(".set_defaultFailedCallback = function(value) { \r\n/// <summary>Sets the service default failed callback function.</summary>\r\n/// <param name=\"value\" type=\"Function\">The service default failed callback function.\r\nvar e = Function._validateParams(arguments, [{name: 'defaultFailedCallback', type: Function}]); if (e) throw e; ").Append(text1).Append("._staticInstance._failed = value; }\r\n");
base._builder.Append(text1).Append(".get_defaultFailedCallback = function() { \r\n/// <summary>Returns the service default failed callback function.</summary>\r\n/// <returns type=\"Function\">The service default failed callback function.</returns>\r\nreturn ").Append(text1).Append("._staticInstance._failed; }\r\n");
..
context.Response.ContentType = "application/x-javascript";
context.Response.Write(text1);
以上代碼實際上就是根據頁面上有的服務生成對應的javascript代碼，比如我們針對上面的HelloWorldService.asmx服務，就會生成如下一段javascript
代碼，注冊到頁面中去：
var HelloWorldService=function() {
this._timeout = 0;
this._userContext = null;
this._succeeded = null;
this._failed = null;
}
HelloWorldService.prototype={
HelloWorld:function(name,succeededCallback, failedCallback, userContext) {
/// <summary>Invoke the HelloWorld WebMethod</summary>
/// <param name=\"name\">WebMethod parameter: name(type: String)</param>
/// <param name=\"succeededCallback\" type=\"function\" optional=\"true\">Callback on successful completion of request</param>
/// <param name=\"failedCallback\" type=\"function\" optional=\"true\">Callback on failure of request</param>
/// <param name=\"userContext\" optional=\"true\">User context data (any JavaScript type)</param>
return Sys.Net._WebMethod._invoke.apply(null, [ this, 'HelloWorld','HelloWorldService.HelloWorld',false,{name:name},succeededCallback, failedCallback, userContext]); },_get_path: function() { return HelloWorldService.get_path(); },
set_timeout: function(value) {
/// <summary>Sets the timeout for this service.</summary>
/// <param name=\"value\" type=\"Number\">The timeout in milliseconds.</param>
var e = Function._validateParams(arguments, [{name: 'timeout', type: Number}]);
if (e) throw e;
if (value < 0) {
throw Error.argumentOutOfRange('value', value, Sys.Res.invalidTimeout);
}
this._timeout = value;
},
get_timeout: function() {
/// <summary>Returns the timeout in milliseconds for this service.</summary>
/// <returns type=\"Number\">The timeout in milliseconds for the service.</returns>
return this._timeout;
set_defaultUserContext: function(value) {
/// <summary>Sets the default userContext for this service.</summary>
/// <param name=\"value\">The default userContext for this service.</param>
this._userContext = value;
get_defaultUserContext: function() {
/// <summary>Returns the default userContext for this service.</summary>
/// <returns>Returns the default userContext for this service.</returns>
return this._userContext;
set_defaultSucceededCallback: function(value) {
/// <summary>Sets the default succeededCallback for this service.</summary>
/// <param name=\"value\" type=\"Function\">The default succeededCallback for this service.</param>
var e = Function._validateParams(arguments, [{name: 'defaultSucceededCallback', type: Function}]);
this._succeeded = value;
get_defaultSucceededCallback: function() {
/// <summary>Returns the default succeededCallback for this service.</summary>
/// <returns type=\"Function\">Returns the default succeededCallback for this service.</returns>
return this._succeeded;
set_defaultFailedCallback: function(value) {
/// <summary>Sets the default FailedCallback for this service.</summary>
/// <param name=\"value\" type=\"Function\">The default FailedCallback for this service.</param>
var e = Function._validateParams(arguments, [{name: 'set_defaultFailedCallback', type: Function}]);
this._failed = value;
get_defaultFailedCallback: function() {
/// <summary>Returns the default failedCallback for this service.</summary>
/// <returns type=\"Function\">Returns the default failedCallback for this service.</returns>
return this._failed;
HelloWorldService._staticInstance = new HelloWorldService();
HelloWorldService.set_path = function(value) {
/// <summary>Sets the service url.</summary>
/// <param name=\"path\" type=\"String\">The service url.
var e = Function._validateParams(arguments, [{name: 'path', type: String}]); if (e) throw e; HelloWorldService._staticInstance._path = value; }
HelloWorldService.get_path = function() {
/// <summary>Returns the service url.</summary>
/// <returns type=\"String\">The service url.</returns>
return HelloWorldService._staticInstance._path; }
HelloWorldService.set_timeout = function(value) {
/// <summary>Sets the service timeout.</summary>
/// <param name=\"value\" type=\"Number\">The service timeout.
var e = Function._validateParams(arguments, [{name: 'timeout', type: Number}]); if (e) throw e; if (value < 0) { throw Error.argumentOutOfRange('value', value, Sys.Res.invalidTimeout); }
HelloWorldService._staticInstance._timeout = value; }
HelloWorldService.get_timeout = function() {
/// <summary>Returns the service timeout.</summary>
/// <returns type=\"Number\">The service timeout.</returns>
return HelloWorldService._staticInstance._timeout; }
HelloWorldService.set_defaultUserContext = function(value) {
/// <summary>Sets the service default userContext.</summary>
/// <param name=\"value\">The service default user context.
HelloWorldService._staticInstance._userContext = value; }
HelloWorldService.get_defaultUserContext = function() {
/// <summary>Returns the service default user context.</summary>
/// <returns>The service default user context.</returns>
return HelloWorldService._staticInstance._userContext; }
HelloWorldService.set_defaultSucceededCallback = function(value) {
/// <summary>Sets the service default succeeded callback.</summary>
/// <param name=\"value\" type=\"Function\">The service default succeed callback function.
var e = Function._validateParams(arguments, [{name: 'defaultSucceededCallback', type: Function}]); if (e) throw e; HelloWorldService._staticInstance._succeeded = value; }
HelloWorldService.get_defaultSucceededCallback = function() {
/// <summary>Returns the service default succeeded callback.</summary>
/// <returns type=\"Function\">The service default succeeded callback.</returns>
return HelloWorldService._staticInstance._succeeded; }
HelloWorldService.set_defaultFailedCallback = function(value) {
/// <summary>Sets the service default failed callback function.</summary>
/// <param name=\"value\" type=\"Function\">The service default failed callback function.
var e = Function._validateParams(arguments, [{name: 'defaultFailedCallback', type: Function}]); if (e) throw e; HelloWorldService._staticInstance._failed = value; }
HelloWorldService.get_defaultFailedCallback = function() {
/// <summary>Returns the service default failed callback function.</summary>
/// <returns type=\"Function\">The service default failed callback function.</returns>
return HelloWorldService._staticInstance._failed; }
HelloWorldService.set_path(\"/Web/HelloWorldService.asmx\");
HelloWorldService.HelloWorld= function(name,onSuccess,onFailed,userContext) { /// <summary>Invoke the HelloWorld WebMethod</summary>
HelloWorldService._staticInstance.HelloWorld(name,onSuccess,onFailed,userContext); }
4、實際調用
這樣服務注冊好之後，我們在頁面上寫的
var fs = HelloWorldService;
fs.set_defaultSucceededCallback(OnShow);
fs.HelloWorld(document.getElementById("name").value);
實際上就是調用注冊好的javascript腳本，然後這些腳本再通過通用的AJAX連接配接XML的異步方式調用背景代碼就可以了
本文轉自永春部落格園部落格，原文連結：http://www.cnblogs.com/firstyi/archive/2006/11/08/554374.html，如需轉載請自行聯系原作者