ASP.NET VIEW STATE INTERVIEW QUESTIONS ANSWERS 2-4 YEARS EXPERIENCED Part 3
21. **Explain ViewState encryption and when to use it.**
ViewState encryption is a technique used to encrypt ViewState contents to prevent tampering or unauthorized access. It should be used when security is a concern and sensitive data is stored in ViewState.
22. **What are the different ViewState modes in ASP.NET?**
There are three ViewState modes: Enabled (default), Disabled, and ReadOnly.
23. **Explain the ReadOnly ViewState mode.**
In ReadOnly mode, ViewState is loaded during postbacks but cannot be modified by developers. This mode is useful for maintaining ViewState integrity while preventing accidental modifications.
24. **How do you handle ViewState in AJAX-enabled pages?**
ViewState should be managed carefully in AJAX-enabled pages to avoid unnecessary ViewState updates and improve performance.
25. **What is the ViewStateUserKey property used for?**
ViewStateUserKey is a property used to associate a unique identifier with ViewState to prevent CSRF (Cross-Site Request Forgery) attacks.
26. **Explain the ViewStateEncryptionMode property.**
ViewStateEncryptionMode property specifies the encryption mode used to encrypt ViewState contents. Available options include Auto, Always, and Never.
27. **What are the security considerations when using ViewState?**
Developers should be aware of potential security vulnerabilities such as ViewState tampering, ViewState injection, and ViewState CSRF attacks.
28. **How can you prevent ViewState tampering?**
Use ViewStateMAC, enable ViewState encryption, and implement server-side validation to prevent ViewState tampering attacks.
29. **What are the best practices for ViewState management?**
Some best practices include minimizing ViewState size, enabling ViewState compression, using ViewState encryption for sensitive data, and disabling ViewState for static or read-only controls.
30. **How do you handle ViewState when using Master Pages?**
ViewState can be accessed and manipulated in content pages that use Master Pages just like in regular ASP.NET pages.