IHttpModule接口的定义：向实现类提供模块初始化和处置事件。它包含2个方法：Dispose()和Init();
自定义IHttpModule接口
实现一个自定义的IHttpModule接口需要2个步骤：
1）实现一个继承了IHttpModule接口的类
2）在Web.config文件中注册这个自定义HttpModule
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print?01 public class CustomerModule:IHttpModule
02 {
03 #region IHttpModule 成员
04 public void Dispose()
05 {
06
07 }
08 public void Init(HttpApplication context)
09 {
10 context.BeginRequest += new EventHandler(context_BeginRequest);
11 context.EndRequest += new EventHandler(context_EndRequest);
12 }
13 void context_BeginRequest(object sender, EventArgs e)
14 {
15 HttpApplication application = (HttpApplication)sender;
16 application.Context.Response.Write("自定义ModuleRequest开始");
17 }
18 void context_EndRequest(object sender, EventArgs e)
19 {
20 HttpApplication application = (HttpApplication)sender;
21 application.Context.Response.Write("自定义ModuleRequest结束");
22 }
23 #endregion
24 }
web.config
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print?1 <httpModules>
2 <add name="customerModule" type="WebApplication3.CustomerModule, WebApplication3"/>
3 </httpModules>
ASP.NET 内置的HttpModule
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print?1 <FONT color=#7b7d62>在C:\Windows\Microsoft.NET\Framework\v2.0.50727\CONFIG\web.config下有很多ASP.NET内置的HttpMoudle默认是加载的如果你不想加载其中的一些可以Remove掉这样可以提高一些性能如：</FONT>
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print?1 <remove name="WindowsAuthentication"/>
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print?1 内置的如下：
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print?01 <httpModules>
02 <add name="OutputCache" type="System.Web.Caching.OutputCacheModule"/>
03 <add name="Session" type="System.Web.SessionState.SessionStateModule"/>
04 <add name="WindowsAuthentication" type="System.Web.Security.WindowsAuthenticationModule"/>
05 <add name="FormsAuthentication" type="System.Web.Security.FormsAuthenticationModule"/>
06 <add name="PassportAuthentication" type="System.Web.Security.PassportAuthenticationModule"/>
07 <add name="RoleManager" type="System.Web.Security.RoleManagerModule"/>
08 <add name="UrlAuthorization" type="System.Web.Security.UrlAuthorizationModule"/>
09 <add name="FileAuthorization" type="System.Web.Security.FileAuthorizationModule"/>
10 <add name="AnonymousIdentification" type="System.Web.Security.AnonymousIdentificationModule"/>
11 <add name="Profile" type="System.Web.Profile.ProfileModule"/>
12 <add name="ErrorHandlerModule" type="System.Web.Mobile.ErrorHandlerModule, System.Web.Mobile, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/>
13 <add name="ServiceModel" type="System.ServiceModel.Activation.HttpModule, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
14 </httpModules>
Global.asax与HttpModule
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print?1 <FONT color=#7b7d62>在ASP.NET中Global.asax是一个全局文件，他可以注册应用程序和Session事件，还可以注册HttpModule中暴露的事件（包括内置的HttpModule和自定义的HttpModule）,有2点注意事项：</FONT>
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print?1 <FONT color=#7b7d62>1）每当一个Http Request到达时，应用程序事件都要出发遍，但是Application_Start和Application_End仅在第一个资源文件被访问时触发。</FONT>
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print?1 <FONT color=#7b7d62>2）HttpModule无法注册和响应Session 事件，Session事件只能在Global.asax中注册</FONT>
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print?01 public class CustomerModule:IHttpModule
02 {
03 //自定义暴露的事件
04 public event EventHandler ExposedEvent;
05
06 #region IHttpModule 成员
07 public void Dispose()
08 {
09
10 }
11 public void Init(HttpApplication context)
12 {
13 context.BeginRequest += new EventHandler(context_BeginRequest);
14 context.EndRequest += new EventHandler(context_EndRequest);
15 }
16 void context_BeginRequest(object sender, EventArgs e)
17 {
18 HttpApplication application = (HttpApplication)sender;
19 application.Context.Response.Write("自定义ModuleRequest开始");
20 }
21 void context_EndRequest(object sender, EventArgs e)
22 {
23 HttpApplication application = (HttpApplication)sender;
24 application.Context.Response.Write("自定义ModuleRequest结束");
25 //触发事件
26 OnExposedEvent(new EventArgs());
27 }
28 #endregion
29
30 protected void OnExposedEvent( EventArgs e)
31 {
32 if (ExposedEvent!=null)
33 {
34 ExposedEvent(this, e);
35 }
36 }
37 }
在Global.asax中添加这样的代码
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print?1 protected void customerModule_ExposedEvent(object sender, EventArgs e)
2 {
3 Response.Write("来自Global.asax");
4 }
其中Global.asax中事件名的定义是：模块名_事件名。其中模块名是你在Web.config中注册的模块名称