Server Based State Management Techniques

ASP.NET offers you a variety of ways to maintain state information on the server, rather than persisting information on the client. With server-based state management, you can decrease the amount of information sent to the client in order to preserve state, however it can use costly resources on the server. The following sections describe three server-based state management features: application state, session state, and profile properties.

Application State:

ASP.NET allows you to save values using application state — which is an instance of the HttpApplicationState class — for each active Web application.Thus, application state is useful for storing information that needs to be maintained between server round trips and between requests for pages.

Application state is stored in a key/value dictionary that is created during each request to a specific URL. You can add your application-specific information to this structure to store it between page requests.

Session State:

ASP.NET allows you to save values by using session state — which is an instance of the HttpSessionState class — for each active Web-application session.Session state is similar to application state, except that it is scoped to the current browser session. If different users are using your application, each user session will have a different session state. In addition, if a user leaves your application and then returns later, the second user session will have a different session state from the first.

Profile Properties:

ASP.NET provides a feature called profile properties, which allows you to store user-specific data. This feature is similar to session state, except that the profile data is not lost when a user's session expires. The ASP.NET profile allows you to easily manage user information without requiring you to create and maintain your own database. In addition, the profile makes the user information available using a strongly typed API that you can access from anywhere in your application. You can store objects of any type in the profile. The ASP.NET profile feature provides a generic storage system that allows you to define and maintain almost any kind of data while still making the data available in a type-safe manner.