Asp.net, Asp.net

It was first released in January 2002 with version 1.0 of the .NET Framework, and is the successor to Microsoft's Active Server Pages (ASP) technology. ASP.NET is built on the Common Language Runtime (CLR), allowing programmers to write ASP.NET code using any supported .NET language.

This is usually a source of confusion among novice ASP.NET programmers that rely on class instance members that are lost with every page request/response cycle.

As such, if the application uses stateful interaction, it has to implement state management on its own. ASP.NET provides various functionality for state management in ASP.NET applications. Conceptually, Microsoft treats "state" as mostly GUI state, big problems may arise when an application needs to keep track of "data state" such as a finite state machine that may be in a transient state between requests (lazy evaluation) or just takes long to initialize.

This is the fastest way; however, in this mode the variables are destroyed when the ASP.NET process is recycled or shut down. Since the application is recycled from time to time this mode is not recommended for critical applications, rather in practice this mode is not recommended for any applications.

Session variables can be persisted across ASP.NET process shutdowns in this mode as well. The main advantage of this mode is it would allow the application to balance load on a server cluster while sharing sessions between servers. This is the slowest method of session state management in ASP.NET.

The state of the controls is encoded and sent to the server at every form submission in a hidden field known as __VIEWSTATE . The server sends back the variable so that when the page is re-rendered, the controls render at their last state. At the server side, the application might change the viewstate, if the processing results in updating the state of any control. The states of individual controls are decoded at the server, and are available for use in ASP.NET pages using the ViewState collection.

Although ASP.NET provides means for intercepting the request at any point during processing, the developer is not forced to funnel requests through a central application or front controller.

The ASP.NET server automatically compiles files (and subdirectories) in this folder into an assembly which is accessible in the code of every page of the site. App_Code will typically be used for data access abstraction code, model code and business code. Also any site-specific http handlers and modules and web service implementation go in this directory. As an alternative to using App_Code the developer may opt to provide a separate assembly with precompiled code.

By default ASP.NET will compile the entire site in batches of 1000 files upon first request. If the compilation delay is causing problems, the batch size or the compilation strategy may be tweaked.

Several controls, such as the Login controls and the Wizard control, use HTML tables for layout by default. Microsoft has solved this problem by releasing the ASP.NET 2.0 CSS Control Adapters , a free add-on that produces compliant accessible XHTML+CSS markup.

Source: Wikipedia > Asp.net