.ASP.NET VIEW STATE INTERVIEW QUESTIONS ANSWERS 2-4+ YEARS EXPERIENCED Part 2
11. **Explain the ViewState lifecycle in ASP.NET.**
ViewState is populated during the Page_PreRender event and is saved to the page's output stream during the Render event. It is then sent to the client and restored during postbacks before the Load event.
12. **How can you improve performance when using ViewState?**
Use ViewState selectively, avoid storing large amounts of data, and consider alternative state management techniques like Session state or caching.
13. **What is the difference between ViewState and Control State?**
Control State is a more secure and predictable version of ViewState that is specific to individual controls and cannot be disabled or overridden by developers.
14. **How do you enable Control State for a control?**
Override the `Page.RegisterRequiresControlState(Control)` method in the control's code-behind and implement the `SaveControlState()` and `LoadControlState()` methods.
15. **What are some scenarios where you should avoid using ViewState?**
Avoid using ViewState for storing sensitive data, large datasets, or when performance is a concern.
16. **Can ViewState be disabled at the application level?**
Yes, ViewState can be disabled at the application level by setting the `EnableViewState` property of the `Page` directive in the web.config file to false.
17. **How do you handle ViewState in dynamically created controls?**
Dynamically created controls should have their ViewState managed explicitly by assigning unique IDs and maintaining state across postbacks.
18. **Explain ViewState compression and when to use it.**
ViewState compression is a technique used to reduce the size of ViewState by compressing its contents before rendering the page. It should be used when ViewState size becomes a performance bottleneck.
19. **What is the impact of ViewState on SEO?**
ViewState does not directly impact SEO, but excessive ViewState can increase page load times, which may indirectly affect SEO rankings.
20. **How can you debug ViewState-related issues?**
Use tools like ViewState Viewer or browser developer tools to inspect the ViewState contents and debug any issues related to ViewState size or corruption.