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)