Asp.Net Life Cycle Events

Life Cycle Events

PreInit

The properties like IsPostBack have been set at this time.

This event will be used when we want to:

1. Set master page dynamically.


2. Set theme dynamically.


3. Read or set profile property values.


4. This event is also preferred if want to create any dynamic controls.

Init

1. Raised after all the controls have been initialized with their default values and any skin settings have been applied.


2. Fired for individual controls first and then for page.

LoadViewState

1. Fires only if IsPostBack is true.


2. Values stored in HiddenField with id as _ViewState decoded and stored into corresponding controls.

LoadPostData

Some controls like:

1. Fires only if IsPostBack is true.


2. Some controls like Textbox are implemented from IPostBackDataHandler and this fires only for such controls.


3. In this event page processes postback data included in the request object pass it to the respective controls.

PreLoad

• Used only if want to inject logic before actual page load starts.

Load

• Used normally to perform tasks which are common to all requests, such as setting up a database query.

Control events

1. This event is fired when IsPostBack is true.


2. Use these events to handle specific control events, such as a Button control's Click event or a TextBox control's TextChanged event.

PreRender
Raised after the page object has created all the controls that are required for rendering which includes child controls and composite controls.

1. Use the event to make final changes to the contents of the page or its controls before the values are stored into the viewstate and the rendering stage begins.


2. Mainly used when we want to inject custom JavaScript logic.

SaveViewState

• All the control values that support viewstate are encoded and stored into the viewstate.

Render
Generates output (HTML) to be rendered at the client side.

• We can add custom HTML to the output if we want here.

Unload

1. Fired for individual controls first and then for page.


2. Used to perform cleanup work like closing open files and database connections.

What do you think?

I hope you will enjoy Asp.Net Life Cycle Events. I would like to have feedback from my blog readers. Your valuable feedback, question, or comments about this article are always welcome.