Variables within a Web Form Page do not retain their values between requests. Requesting a Web Form Page is similar to starting and stopping an application. After the page is finished being processed, you must start all over again with a blank slate.
If you need to maintain the value of a variable across multiple page requests, you need to do something special. In this chapter, you learn about three methods of maintaining the state of variables. You will learn
How to use View State to retain the state of variables for a particular page
How to use Session State to retain the state of variables for a particular user
How to use Application ...