ASP.NET Page Life Cycle
Dev Basics Series
Jay Harris

About the Talk Covers
Life Cycle
Discuss: Data Binding
ASP.NET Page Life Cycle Tips & Tricks
Proper use of Data Binding Events Pain Points
Involves only ASP.NET Events
No MVC. No Silverlight.
No Controls or DataSource Controls
Tips & Tricks. And Traps.
Overview
What to expect out of this session

About the Speaker Covers
Life Cycle
Jay Harris Data Binding
Software Consultant Tips & Tricks
.NET Developer Pain Points
Ask Questions Anytime
Please Give Feedback!
http://www.speakerrate.com/jayharris/
Overview
What to expect out of this session

The Agenda
Anatomy of the ASP.NET Page Life Cycle

Page Start Agenda
Start
System Assigns Properties:
Request
Response
UICulture
System determines if the request
is new or postback
The Agenda
Anatomy of the ASP.NET Page Life Cycle

Page Initialization Agenda
Start
System Prepares Controls: Initialization
Available by UniqueID
Properties set from code/CIF values
Applies Theme & MasterPage
Handled in PreInit
The Agenda
Anatomy of the ASP.NET Page Life Cycle

Page Load Agenda
Start
If IsPostBack: Initialization
Restores Properties from State Load
The Agenda
Anatomy of the ASP.NET Page Life Cycle

Render Agenda
Start
Saves ViewState & Renders Initialization
Load
Render
The Agenda
Anatomy of the ASP.NET Page Life Cycle

Control Validation Agenda
Start
If IsPostBack & Validators exist: Initialization
Runs Validate() for All Validators Load
…even the disabled ones Validation
Render
The Agenda
Anatomy of the ASP.NET Page Life Cycle

PostBack Events Agenda
Start
If IsPostBack: Initialization
Runs any Event Handlers as needed Load
Validation
Includes events such as: Events
Render
TextBox.TextChanged
DropDownList.SelectedIndexChanged
Button.Click
The Agenda
Anatomy of the ASP.NET Page Life Cycle

Easy to Remember Agenda
Start
Initialization
Load
Validation
“SILVER!” Events
(as in medals & bars) Render
The Agenda
Anatomy of the ASP.NET Page Life Cycle

Easy to Remember Agenda
Start
Load
Initialization
Validation
Wait. “SLIVER?!?” Events
(no, not wood) Render
The Agenda
Anatomy of the ASP.NET Page Life Cycle

Easy to Remember Agenda
Start
Load
Initialization
Validation
Huh? “LIVER?!?” Events
(eww. gross. and there’s no onions) Render
The Agenda
Anatomy of the ASP.NET Page Life Cycle

Easy to Remember Agenda
Start
Initialization
Load
Validation
“Hi-yo, Silver, away!” Events
(The Lone Ranger) Render
The Agenda
Anatomy of the ASP.NET Page Life Cycle

Running the Show
Harnessing the ASP.NET Page Life Cycle*

Subjected to the terms,
Running the Show
limitations, availability, whims,
will, desires, rules, patterns,
provisions, agreements,
covenants, conditions, assigns,
Harnessing the ASP.NET Page Life Cycle* successors, and approval of the
ASP.NET worker process.

Debugging Events Features
Page-Level Tracing: Tracing
Page-Level
<%@ Page Trace=“true” %>
Running the Show
Harnessing the ASP.NET Page Life Cycle*

Debugging Events Features
Page-Level Tracing: Tracing*
Page-Level*
<%@ Page Trace=“true” %>
*Not available after Render
Subjected to the terms,
Running the Show
limitations, availability, whims,
will, desires, rules, patterns,
provisions, agreements,
covenants, conditions, assigns,
Harnessing the ASP.NET Page Life Cycle* successors, and approval of the
ASP.NET worker process.

Debugging Events Features
Application-Level Tracing: Tracing*
Page-Level*
App-Level
<configuration>
<system.web>
<trace enabled=“true” />
</system.web>
</configuration>
Running the Show
Harnessing the ASP.NET Page Life Cycle*

Debugging Events Features
Application-Level Tracing: Tracing*
Page-Level*
App-Level*
<configuration>
<system.web>
<trace enabled=“true” />
</system.web>
</configuration>
*Site-Wide Performance Hit
Subjected to the terms,
Running the Show
limitations, availability, whims,
will, desires, rules, patterns,
provisions, agreements,
covenants, conditions, assigns,
Harnessing the ASP.NET Page Life Cycle* successors, and approval of the
ASP.NET worker process.

Event Wiring Features
Using the Constructor: Tracing*
Wiring
Manual
public MyPage()
{
this.Load += PageLoad;
}
protected void PageLoad(…)
Running the Show
Harnessing the ASP.NET Page Life Cycle*

Event Wiring Features
Using the Constructor: Tracing*
Wiring*
Manual*
public MyPage()
{
this.Load += PageLoad;
}
protected void PageLoad(…)
*Wire Control events in Page Init
Subjected to the terms,
Running the Show
limitations, availability, whims,
will, desires, rules, patterns,
provisions, agreements,
covenants, conditions, assigns,
Harnessing the ASP.NET Page Life Cycle* successors, and approval of the
ASP.NET worker process.

Event Wiring, Auto Features
Auto-Wire via Page_EventName: Tracing*
Wiring*
Manual*
protected void Page_Load(…) Auto-Wire
{
//Do some stuff
}
Running the Show
Harnessing the ASP.NET Page Life Cycle*

Event Wiring, Auto Features
Auto-Wire via Page_EventName: Tracing*
Wiring*
Manual*
protected void Page_Load(…) Auto-Wire*
{
//Do some stuff
}
*Page only. Not for controls.
*Performance Hit.
Subjected to the terms,
Running the Show
limitations, availability, whims,
will, desires, rules, patterns,
provisions, agreements,
covenants, conditions, assigns,
Harnessing the ASP.NET Page Life Cycle* successors, and approval of the
ASP.NET worker process.

Event Execution Features
Top-Down Control Tree Execution Tracing*
Wiring*
Execution
First load the Page Tree
…then load the Container Control
…then load the Child Control
Running the Show
Harnessing the ASP.NET Page Life Cycle*

Event Execution Features
Top-Down Control Tree Execution Tracing*
Wiring*
Execution*
First load the Page Tree*
…then load the Container Control
…then load the Child Control
*Except: Initialization & Unload
First unload Controls, then the Page
Subjected to the terms,
Running the Show
limitations, availability, whims,
will, desires, rules, patterns,
provisions, agreements,
covenants, conditions, assigns,
Harnessing the ASP.NET Page Life Cycle* successors, and approval of the
ASP.NET worker process.

Event Execution Features
Index-based Collection Execution Tracing*
Wiring*
Execution*
page.Controls[0].OnLoad Tree*
page.Controls[1].OnLoad Collection
page.Controls[2].OnLoad
…
page.Controls[n].OnLoad
Running the Show
Harnessing the ASP.NET Page Life Cycle*

Event Execution Features
Index-based Collection Execution Tracing*
Wiring*
Execution*
page.Controls[0].OnLoad Tree*
page.Controls[1].OnLoad Collection*
page.Controls[2].OnLoad
…
page.Controls[n].OnLoad
* When was it added to Controls?
Subjected to the terms,
Running the Show
limitations, availability, whims,
will, desires, rules, patterns,
provisions, agreements,
covenants, conditions, assigns,
Harnessing the ASP.NET Page Life Cycle* successors, and approval of the
ASP.NET worker process.

Event Execution Features
Index-based Collection Execution Tracing*
Wiring*
Execution*
page.Controls[0].OnLoad Tree*
page.Controls[1].OnLoad Collection*
page.Controls[2].OnLoad
…
page.Controls[n].OnLoad
* When was it added to Controls?
Subjected to the terms,
Running the Show
limitations, availability, whims,
will, desires, rules, patterns,
provisions, agreements,
covenants, conditions, assigns,
Harnessing the ASP.NET Page Life Cycle* successors, and approval of the
ASP.NET worker process.

Loading ViewState Features
Control State is loaded twice Tracing*
Wiring*
Execution*
Once immediately prior to Load ViewState
Once immediately following Load
Running the Show
Harnessing the ASP.NET Page Life Cycle*

Loading ViewState Features
Control State is loaded twice Tracing*
Wiring*
Execution*
Once immediately prior to Load ViewState*
Once immediately following Load
*Not restored if modified prior
Subjected to the terms,
Running the Show
limitations, availability, whims,
will, desires, rules, patterns,
provisions, agreements,
covenants, conditions, assigns,
Harnessing the ASP.NET Page Life Cycle* successors, and approval of the
ASP.NET worker process.

Displaying Data
Effectively Binding Dynamic Data to the Page

DataBind(); Data
DataBind();
Control.DataBind();
Only for the specific contol
and its child controls
Page.DataBind();
Binds all controls on the page
Displaying Data
Effectively Binding Dynamic Data to the Page

Binding Events Data
DataBind();
DataBinding Events
Begins DataBinding of a control DataBinding
Displaying Data
Effectively Binding Dynamic Data to the Page

Binding Events Data
DataBind();
RowCreated / ItemCreated Events
Manipulating item markup DataBinding
Cannot be dependent on control data RwCreated
Row vs. Item Usage:
RowCreated: GridView
ItemCreated: DataGrid,ListView,
Repeater, and everything else.
Displaying Data
Effectively Binding Dynamic Data to the Page

Binding Events Data
DataBind();
RowDataBound / ItemDataBound Events
Manipulating item data DataBinding
Data is available within controls RwCreated
RwDBound
Row vs. Item Usage:
RowCreated: GridView
ItemCreated: DataGrid, ListView,
Repeater, and everything else.
Displaying Data
Effectively Binding Dynamic Data to the Page

Resources & Questions
Resources
MSDN: http://tinyurl.com/AspNetPageLifeCycle
Blog: http://www.cptloadtest.com
Twitter: @jayharris
Questions?
Wrap-up
Taking the Next Steps with the ASP.NET Page Life Cycle

Thank You
Jay Harris Online
Blog: http://www.cptloadtest.com
Twitter: @jayharris
Feedback
Rate: http://www.speakerrate.com/jayharris
Wrap-up
Taking the Next Steps with the ASP.NET Page Life Cycle