asp.net page life cycle
DESCRIPTION
The presentation deals with ASP.NET page life cycle and gives you a brief introduction of the events that are fired during each phaze of page processing.TRANSCRIPT
ASP.NET Page Life Cycle
Presented By : Abhishek Surhttp://www.abhisheksur.com/
Table of ContentIntroductionApplication Life Cycle
IIS Request ProcessApplication PoolWorker ProcessHTTP Handler/Module
ASP.NET Page Life CyclePage Life Cycle StepsPage Life Cycle Events
Life Cycle for Master Page and User ControlQA
IntroductionWhen Clients request for an aspx page from
browser and lot of stuffs happens in background to produce the output or sending response to client. This evolves ASP.NET Page Lifecycle.
ASP.NET Page Life Cycle is very much important to know for each and every developer to developed an ASP.NET Web Application.
All events, data processing, dynamic control creation, view state, postback, rendering etc. are depends with Page Life Cycle.
Application Life Cycle1. Client Request For
Information2. Request comes to Server3. Server Process the request4. Send the response back to
Client
Application Life Cycle - Contd.Key terms to remember
HTTP.SYS WAS Application Pool Worker Process
http://blogs.thesitedoctor.co.uk/tim/2006/06/30/Complete+Lifecycle+Of+An+ASPNet+Page+And+Controls.aspx
Application Life Cycle – Contd.Key Terms To Remember
Http ModuleHttp HandlerHttp Pipeline
End Of Application Life Cycle – Start Page Life CycleRequest Passes Through HTTP Pipe LineThis Start Page Life Cycle
ASP.NET Page Life Cycle BeginsStartInitializationLoadValidationEventsRender
S I
L
V E
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Page Life Cycle - StartClient Request For ResourceRequest Comes To Server (IIS)IIS Process the Initial ProcessingRequest Passed through HTTP- Pipe LineASP.NET Page Life Cycle Starts
Page Life Cycle - InitializationSet Postback propertiesUnique ID for Each Control in the PageThemes needs to be initializedDynamic control need to be created
Page Life Cycle - LoadIf the Request is the post back request then it
loads data from View States and Control State
Page Life Cycle - ValidationValidate the pages ControlUpdates the IsValid property
Page Life Cycle - EventsThis will only fired if the request is an
postback event.Like, if the post back is happened for an
Button Click. Button Click event will fired.
Page Life Cycle - RenderBefore Rendering All View State data has
been set.Render() method for all control has been
called and write the out put on output stream.
Page Life Cycle - Events
http://msdn.microsoft.com/en-us/library/ms178472.aspx
ASP.NET Page Life Cycle EventsPreInit Init PreLoad LoadControl EventsPreRender SaveViewStateRender Unload
Page Life Cycle – EventsPreInit()
This is the first event which raised in asp.net page lifecycle
Check for Request is for Post Back or not. All dynamic control need to be created Theme Change, Master Page Set at runtime
Init() Raised after all controls have been initialized Build up a tree of controls from the ASPX file Turn on view state monitoring – any changes in
control will be tracked by View State for future.
Page Life Cycle - EventsPreLoad()
Load view state data for page and controls Load Postback data if needed We can process any kind operation that need to
perform before page load
Load() OnLoad methods control called for each and every
control We can create the connection initialization for any
kind of external source like database connection We can also set the control properties
Page Life Cycle - EventsControl Events
If this is an postback request , Corresponding events will triggered. Like, if the post back is happing for button click, then Button_Click Event will fired.
PreRender Each control of the page has a PreRender event which is
being invoked. EnsureChildControls is also being called during this events DataBind method for all control has also been called If we want to change any thing to any control this is the last
event where we can do because after the pageRender starts
Page Life Cycle - EventsSaveViewState
ViewState Monitoring is turned off as here all the ViewState Data need to be saved.
View State data saved in hidden filed called _VIEWSTATE
Render Pages calls the Render method for each and every
control. Text writer that writes the output to the as output
stream Output steam set to the page's Response property.
Page Life Cycle - EventsUnload
This is the last event of asp.net page life cycle This ensure the Request and Response has been
set to null. This is called only after the content of the page fully
rendered and response sent to client
Page Life Cycle - Master Page and User ControlsMasterPage gets initialized from the Page class in the
init phaze of page. The content of Masterpage gets loaded side by side as the page gets loaded.
User control will be initialized and added to the page and before page gets initialized
After page Onload, MasterPage_OnLoad gets called and UserControl_Onload gets called sequentially.
Followed by each of Page events, masterPage events gets called and next Usercontrol events are called.
During the unload phaze, Usercontrol gets unloaded first and then masterpage and Page in sequence.
For further reference refer to : http://blogs.thesitedoctor.co.uk/tim/2006/06/30/Complete+Lifecycle+Of+An+ASPNet+Page+And+Controls.aspx
Q/A
Thank you