Request Life cycle

The global application class is also used to process the life cycle (Request lifecycle) events that describe a single request. The ASP. NET Framework creates an instance of the global class. and uses the event that it defines to process the request until the response is generated and sent back to the browser.

Request life cycle events defined by the HttpApplication class
Name	Description
BeginRequest	The first event that the ASP. NET Framework fires when a new request is received .
Authenticaterequestpostauthenticaterequest	The AuthenticateRequest event is triggered when the ASP. NET Framework needs to identify the user who made the request . After all event handlers have been processed, the Postauthenticaterequest event is triggered.
Resolverequestcachepostresolverequestcache	The Resolverequestcache event is triggered when the ASP. NET Framework requires an authorization request . Postresolverequestcache event is triggered after all event handlers have been processed
Mapreuesthandlerpostmaprequesthandler	The Mapreuesthandler event is triggered when the ASP. NET Framework needs to request a lookup handler . Postmaprequesthandler event is triggered after all event handlers have been processed
Acquirerequeststatepostacquirerequeststate	When the ASP. NET Framework requires a state (session state) associated with a request , the AcquireRequestState event is triggered after all event handlers have been processed. The Postacquirerequeststate event will be triggered
Prerequesthandlerexecutepostrequesthandlerexecete	These events are triggered immediately before and after a request is processed by the handler.
Releaserequeststatepostreleaserequeststate	When the ASP . NET Framework no longer needs the State (session state) associated with the request , the ReleaseRequestState event is triggered after all event handlers have been processed. The Postreleaserequeststate event will be triggered
Updaterequestcache	This event is triggered so that the module responsible for caching updates its state .
Logrequestpostlogerequest	When the ASP. NET Framework needs to log the details of this request , the Logrequeste event is triggered after all event handlers have been processed, The Postlogerequest event will be triggered
EndRequest	When the ASP. NET Framework finishes processing the request, the EndRequest event is triggered when it prepares to send a response to the browser.
Presendrequesthandlers	The Presendrequesthandlers event is triggered before the HTTP header is sent to the browser, and the Presendrequesthandlers event is triggered after the header is sent and before the content is sent to the browser.
Error	The error event will be triggered when errors are encountered -any stage in which the request is processed may trigger this event.

Request Life cycle