Page Life-Cycle Stages

1. Page Request:

The Page Request stage determines whether the ASP.NET page needs to be compiled and parsed or if a cached version can be sent to the client. This stage initiates the processing of the page.

2. Start:

During the Start stage, ASP.NET sets page properties such as Request and Response. It also identifies if the page is a postback and establishes the UI culture for localization purposes.

3. Initialization:

In the Initialization stage, controls on the page become available, their UniqueID is set, and the Master Page and Theme are applied to the page.

4. Load:

The Load stage involves loading controls with data, especially if it is a postback. Information is retrieved from view state and control state to restore the state of the controls.

5. Postback Event Handling:

If the request is a postback, control event handlers are invoked during this stage. Additionally, the Validate method of validator controls is executed to determine the validity of the input. After validation, the handler for the event causing the validation is called.

6. Rendering:

During the Rendering stage, page properties like Response and Request are unloaded, and necessary clean-up operations are performed. Before rendering the page, the view state for the page and all controls is saved to maintain their state.

7. Unload:

The Unload stage is the final phase where page properties, such as Response and Request, are unloaded, and any remaining clean-up tasks are performed before the page is discarded. This stage marks the completion of the page life cycle.