Friday, June 30, 2006

Complete Lifecycle of an ASP.Net page and controls

Julian Voelcker raised a question on the MsWebDev mailing list the other day that I've been meaning to investigate for a while as it's something that I have to double check on every time I write a new custom control -the various lifecycles an ASP.Net page.

Many people have blogged about the lifecycle of an ASP.Net Page or Master Page but every time I need to find the complete lifecycle of a control it’s not so easy. Today I wrote a couple of test pages to generate a reference.

The pages are very simple, I just overrode every method I could find and wrote to the trace. For completeness when the method called its base I wrapped it with “Start MethodName” and “End MethodName” (if you look at the trace outputs below you will see why). I did this for the Master Page (.master), Page (.aspx), User Control (.ascx) and Web Control (.cs), the page structre was simple:

• Master Page
  • Page
    • User Control
    • Web Control

For clarity I’ve split the produced trace into 5 individual reference sections:

• Master Page
• Page
• Custom User Control
• Custom Web Control
• Complete Lifecycle

ASP.Net 2.0 Master Page Life Cycle

• Start Construct()
• End Construct()
• Start FrameworkInitialize()
• End FrameworkInitialize()
• Start AddParsedSubObject(object obj)
  • CreateControlCollection()
  • Start AddedControl(Control control, int index)
  • End AddedControl(Control control, int index)
• End AddParsedSubObject(object obj)
• Start AddParsedSubObject(object obj)
  • Start AddedControl(Control control, int index)
  • End AddedControl(Control control, int index)
• End AddParsedSubObject(object obj)
• Start AddParsedSubObject(object obj)
  • Start AddedControl(Control control, int index)
  • End AddedControl(Control control, int index)
• End AddParsedSubObject(object obj)
• Start AddParsedSubObject(object obj)
  • Start AddedControl(Control control, int index)
  • End AddedControl(Control control, int index)
• End AddParsedSubObject(object obj)
• Start AddParsedSubObject(object obj)
  • Start AddedControl(Control control, int index)
  • End AddedControl(Control control, int index)
• End AddParsedSubObject(object obj)
• ResolveAdapter()
• Start OnInit(EventArgs e)
• End OnInit(EventArgs e)
• Start TrackViewState()
• End TrackViewState()
• Start OnLoad(EventArgs e)
  • Page_Load(object sender, EventArgs e)
• End OnLoad(EventArgs e)
• Start EnsureChildControls()
  • ResolveAdapter()
  • Start CreateChildControls()
  • End CreateChildControls()
• End EnsureChildControls()
• Start OnPreRender(EventArgs e)
• End OnPreRender(EventArgs e)
• SaveViewState()
• SaveViewState()
• HasControls()
• Start RenderControl(HtmlTextWriter writer)
  • Start Render(HtmlTextWriter writer)
    • Start RenderChildren(HtmlTextWriter writer)
    • End RenderChildren(HtmlTextWriter writer)
  • End Render(HtmlTextWriter writer)
• End RenderControl(HtmlTextWriter writer)

ASP.Net 2.0 Page Life Cycle

• ResolveAdapter()
• DeterminePostBackMode()
• Begin PreInit
  • Start OnPreInit(EventArgs e)
  • End OnPreInit(EventArgs e)
  • HasControls()
  • Start RemovedControl(Control control)
  • End RemovedControl(Control control)
  • ResolveAdapter()
  • Start AddedControl(Control control, int index)
  • End AddedControl(Control control, int index)
• End PreInit
• Begin Init
  • ResolveAdapter()
  • Start OnInit(EventArgs e)
  • End OnInit(EventArgs e)
  • Start TrackViewState()
  • End TrackViewState()
• End Init
• Begin InitComplete
  • Start OnInitComplete(EventArgs e)
  • End OnInitComplete(EventArgs e)
• End InitComplete
• Begin PreLoad
  • Start OnPreLoad(EventArgs e)
  • End OnPreLoad(EventArgs e)
• End PreLoad
• Begin Load
  • Start OnLoad(EventArgs e)
    • Page_Load(object sender, EventArgs e)
  • End OnLoad(EventArgs e)
• End Load
• Begin LoadComplete
  • Start OnLoadComplete(EventArgs e)
  • End OnLoadComplete(EventArgs e)
• End LoadComplete
• Begin PreRender
  • Start EnsureChildControls()
    • ResolveAdapter()
    • Start CreateChildControls()
    • End CreateChildControls()
  • End EnsureChildControls()
  • Start OnPreRender(EventArgs e)
  • End OnPreRender(EventArgs e)
• End PreRender
• Begin PreRenderComplete
  • Start OnPreRenderComplete(EventArgs e)
  • End OnPreRenderComplete(EventArgs e)
• End PreRenderComplete
• SaveViewState()
• Begin SaveState
  • SaveViewState()
  • HasControls()
  • Start SavePageStateToPersistenceMedium(object state)
    • ResolveAdapter()
  • End SavePageStateToPersistenceMedium(object state)
• End SaveState
• Begin SaveStateComplete
  • Start OnSaveStateComplete(EventArgs e)
  • End OnSaveStateComplete(EventArgs e)
• End SaveStateComplete
• Begin Render
  • CreateHtmlTextWriter(System.IO.TextWriter tw)
  • Start RenderControl(HtmlTextWriter writer)
    • Start Render(HtmlTextWriter writer)
      • Start RenderChildren(HtmlTextWriter writer)
      • End RenderChildren(HtmlTextWriter writer)
    • End Render(HtmlTextWriter writer)
  • End RenderControl(HtmlTextWriter writer)
• End Render
• CreateHtmlTextWriter(System.IO.TextWriter tw)

ASP.Net 2.0 User Control Life Cycle

• Start Construct()
• End Construct()
• Start FrameworkInitialize()
• End FrameworkInitialize()
• ResolveAdapter()
• Start OnInit(EventArgs e)
• End OnInit(EventArgs e)
• Start TrackViewState()
• End TrackViewState()
• Start OnLoad(EventArgs e)
  • Page_Load(object sender, EventArgs e)
• End OnLoad(EventArgs e)
• Start EnsureChildControls()
  • ResolveAdapter()
  • Start CreateChildControls()
  • End CreateChildControls()
• End EnsureChildControls()
• Start OnPreRender(EventArgs e)
• End OnPreRender(EventArgs e)
• SaveViewState()
• SaveViewState()
• HasControls()
• Start RenderControl(HtmlTextWriter writer)
  • Start Render(HtmlTextWriter writer)
    • Start RenderChildren(HtmlTextWriter writer)
    • End RenderChildren(HtmlTextWriter writer)
  • End Render(HtmlTextWriter writer)
• End RenderControl(HtmlTextWriter writer)

ASP.Net 2.0 Web Control Life Cycle

• Constructor Test()
• Start ApplyStyleSheetSkin(Page page)
• End ApplyStyleSheetSkin(Page page)
• ResolveAdapter()
• Start OnInit(EventArgs e)
• End OnInit(EventArgs e)
• Start TrackViewState()
• End TrackViewState()
• Start OnLoad(EventArgs e)
• End OnLoad(EventArgs e)
• Start EnsureChildControls()
  • ResolveAdapter()
  • Start CreateChildControls()
  • End CreateChildControls()
• End EnsureChildControls()
• Start OnPreRender(EventArgs e)
• End OnPreRender(EventArgs e)
• SaveViewState()
• SaveViewState()
• HasControls()
• Start RenderControl(HtmlTextWriter writer)
  • Start Render(HtmlTextWriter writer)
    • Start RenderBeginTag(HtmlTextWriter writer)
      • Start AddAttributesToRender(HtmlTextWriter writer)
      • End AddAttributesToRender(HtmlTextWriter writer)
    • End RenderBeginTag(HtmlTextWriter writer)
  • Start RenderContents(HtmlTextWriter writer)
    • Start RenderChildren(HtmlTextWriter writer)
    • End RenderChildren(HtmlTextWriter writer)
  • End RenderContents(HtmlTextWriter writer)
  • Start RenderEndTag(HtmlTextWriter writer)
  • End RenderEndTag(HtmlTextWriter writer)
  • End Render(HtmlTextWriter writer)
• End RenderControl(HtmlTextWriter writer)

Complete Lifecycle of an ASP.Net page and controls

Useful Links:            Comments [18]  Trackback

Tags: ASP.Net

Thursday, March 01, 2007 7:20:41 AM (GMT Standard Time, UTC+00:00)

You're welcome, I'm glad it was of use to you :)

Tim

Wednesday, December 26, 2007 6:56:31 PM (GMT Standard Time, UTC+00:00)

Good job. Anytime I write some user or custom controls I always get mad about lifecycle. Anyway, I think ms should have made it simpler. Especially the DataBound events are not so smart as they often simply destroy the pre-create child hierarchy and build it again. (If you used Reflector against System.Web, you know what I mean).
Ah ! Maybe you should trace twice : one for not PostBack scenario (Http-Get) and one for PostBack (Http-Post). I forgot the details now, but some months ago I noticed that the events raise in a slightly different order, especially the PreRender event.
Best regards, Alex

alex

Wednesday, May 14, 2008 7:40:21 PM (GMT Daylight Time, UTC+01:00)

Hi,

I was going through it. Now doubt you have done the best job in the world. But can you do the favour of Putting the trace along with PostBack.Since some of really important events like LoadPostBackData and LoadViewStateData aren't there.

Thanks and Regards
Mohit Thakral

Mohit Thakral

Friday, October 31, 2008 1:16:26 PM (GMT Standard Time, UTC+00:00)

A great job it is.

I'm wondering if you can share the source with us on how you traced it.

I managed to re-produce a lot of it but still missing a few of yours. I will print it out and stick it up on the wall for all to look on a day to day basis.

To me, it's a great contribution to the community.

Much appreciate it.

Liming

Thursday, November 06, 2008 4:32:22 PM (GMT Standard Time, UTC+00:00)

Totally agree with Liming.

I'd also like to see the code, if not posible to post it, could you please e-mail it.

Thanks bunch.

Miro

Tuesday, November 25, 2008 2:19:36 PM (GMT Standard Time, UTC+00:00)

I've had a look around for the source but I couldn't find it in my archives, I will have it somewhere so bare with me but I may just update it for 3.5 incase there are additional events etc.

Tim

Tim Gaunt

Wednesday, August 12, 2009 3:33:27 PM (GMT Daylight Time, UTC+01:00)

Good work, its very useful. can i have the source code of it, could you please mail me?

Thanks in advance
Palavesh

Palavesh

Sunday, September 13, 2009 8:33:37 AM (GMT Daylight Time, UTC+01:00)

Hi Tim, This is an amazing work and very useful. Thanks for posting.

Sandeep

Tuesday, September 29, 2009 4:26:13 AM (GMT Daylight Time, UTC+01:00)

thanks for your post! It is useful for me! but it is more useful if you add more detail, such as where each step happen (server side or client side)
-- sorry about my bad English--

vnd

Monday, January 11, 2010 3:44:04 PM (GMT Standard Time, UTC+00:00)

Thanks a lot! I'm just missing Validation there.

Vlado

Saturday, June 25, 2011 7:14:59 AM (GMT Daylight Time, UTC+01:00)

Great post. The most complete information on page lifecycle. May I also recommend this post:
<a href='http://www.thoughtresults.com/asp-net-page-lifecycle'>ASP.NET Page LifeCycle</a>

Micheal

Thursday, October 20, 2011 9:18:51 PM (GMT Daylight Time, UTC+01:00)

Nice Post!
Very useful information!
Thank you very much!

Evandro Junqueira Ramos