How to used HttpModule

HttpModulesallowyoutoextendtheexistingASP.NETpipeline.ThemostcommonuseofHTTPModulesispreand/orepostprecessingofrequests.InternallyASP.NETutilizescustommodules(httpmodules)for:outputcaching,authenticationandauthorizationetc.Therefore,ifyoueverneedtotapintothepiplelinetoaltertherequestinanyway,lookintoHttpModulesastheyprovidearelativelyeasywayforyoutodojustthat(similiartohowISAPIfiltershelpedachievepre/postprocessingcapabilities).

TodevelopanHttpModuleyouarerequiredtodothefollowing:

YouclassmustimplementtheiHttpModuleInterface

BoththeInit(..)andDispose()methodsmustbeinyourclassdefinitions

Belowisasimpleexamplethatoutputs"HttpModulesaysHello!"toeachandeveryrequest.YouwillnoticethatIwiredaneventintheInit(..)methodthatcallsOnBeginRequestatthebeginningofeveryrequest.

usingSystem; usingSystem.Web; namespaceCSharpFriends.Samples { publicclassCSharpFriendsHttpModule:IHttpModule { publicCSharpFriendsHttpModule() { [code]} /// ///RequiredbytheinterfaceIHttpModule /// publicvoidDispose() { } /// ///RequiredbytheinterfaceIHttpModule ///IalsowireuptheBeginRequestevent. /// publicvoidInit(System.Web.HttpApplicationApp) { App.BeginRequest+=newSystem.EventHandler(OnBeginRequest); App.EndRequest+=newSystem.Eventhandler(OnEndRequest); } [/code] publicvoidOnBeginRequest(objectsender,EventArgse) { //HttpRequestrequest=((HttpApplication)sender).Request; HttpApplicationapp=((HttpApplication)sender; app.Context.Response.Write("HttpModulesaysHello!"); } publicvoidOnEndRequest(objectsender,EventArgse) { HttpApplicationapp=(HttpApplication)sender; app.Context.Response.Write("HttpModulesaysBaby!"); } } }

Inyourweb.config,addthefollowingelements:

<httpModules>

<addtype="CSharpFriends.Samples.CSharpFriendsHttpModule,Test"name="CSharpFriendsHttpModule"/></httpModules>

[/code]

[/code]