List ASP.NET Page Life Cycle events

Page Event
Controls Initialized
Is ViewState Enabled
 When is this Event Raised


No No After the start stage is complete and before the initialization stage begins This event can be used for the following:
1) Check the IsPostBack property. The IsCallback and IsCrossPagePostBack properties are also set at this time.
2) Create or re-create dynamic controls.
3) Set a master page dynamically.
4) Set the Theme property dynamically.
5) Read or set profile property values.
Note: If the request is a postback, the values of the controls have not yet been restored from view state.


Not guaranteed No After all controls have been initialized and any skin settings have been applied. The Init event of individual controls occurs before the Init event of the page. This event can be used to read or initialize control properties.


Not guaranteed Yes At the end of the page’s initialization stage.
Only one operation takes place between the Init and InitComplete events: tracking of view state changes is turned on. View state tracking enables controls to persist any values that are programmatically added to the ViewState collection.
This event can be used to make changes to view state that you want to make sure are persisted after the next postback.


Not guaranteed Yes This event happens only at postbacks
The Viewstate which has been saved in the __VIEWSTATE during the previous page visit (via the SaveViewState event) is loaded and then populated into the control hierarchy.


Not guaranteed Yes This event happens only at postbacks
During this event, the posted form data is loaded into the appropriate controls.


Yes Yes After the page loads view state for itself and all controls, and after it processes postback data that is included with the Request instance.


Yes Yes
The Page object calls the OnLoad method on the Page object, and then recursively does the same for each child control until the page and all controls are loaded. The Load event of individual controls occurs after the Load event of the page.
The OnLoad event can be used to set control properties and database connections.

Control events

Yes Yes Raised at the end of the event-handling stage.
These events can be used to handle specific control events, such as a Button control’s Click event or a TextBox control’s TextChanged event.
Note: In a postback request, if the page contains validator controls, check the IsValid property of the Page and of individual validation controls before performing any processing.


Yes Yes Raised after the Page object has created all controls that are required in order to render the page, including child controls of composite controls.This event can be used for tasks that require that all other controls on the page be loaded.


Yes Yes

The Page object raises the PreRender event on the Page object, and then recursively does the same for each child control. The PreRender event of individual controls occurs after the PreRender event of the page.

 The event can be used to make final changes to the contents of the page or its controls before the rendering stage begins.


Yes Yes
Raised after each data bound control whose DataSourceID property is set calls its DataBind method.


Yes Yes
Raised after view state and control state have been saved for the page and for all controls.
Any changes to the page or controls at this point affect rendering, but the changes will not be retrieved on the next postback.


Yes Yes This is not an event; instead, at this stage of processing, the Page object calls this method on each control. All ASP.NET Web server controls have a Render method that writes out the control’s markup to send to the browser.

If you create a custom control, you typically override this method to output the control’s markup. However, if your custom control incorporates only standard ASP.NET Web server controls and no custom markup, you do not need to override the Render method.
We do not need to explicitly render the control in code because a user control automatically incorporates rendering.


Yes Yes Raised for each control and then for the page.
This event can be used to do final cleanup for specific controls, such as closing control-specific database connections.
Note: During the unload stage, the page and its controls have been rendered, so you cannot make further changes to the response stream. If you attempt to call a method such as the Response.Write method, the page will throw an exception.

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