server-side web application framework designed for web development to produce dynamic web pages. This practice is automatic in Visual Studio and other IDEs, though the user can change the code-behind page.It was developed by Microsoft to allow programmers to build dynamic web sites, web applications and web services. Also, in the web application format, the cs is a partial class that is linked to the pagename.file.It was first released in January 2002 with version 1.0 of the . The designer file is a file that is autogenerated from the ASPX page and allows the programmer to reference components in the ASPX page from the CS page without having to declare them manually, as was necessary in ASP. When using this style of programming, the developer writes code to respond to different events, such as the page being loaded, or a control being clicked, rather than a procedural walkthrough of the document. NET's code-behind model marks a departure from Classic ASP in that it encourages developers to build applications with separation of presentation and content in mind.
Web applications need to be compiled before deployment, while web sites structures allows the user to copy the files directly to the server without prior compilation. NET Web Pages (a platform using only Razor pages) have merged into a unified MVC 6.This is similar to the separation of the controller from the view in model–view–controller (MVC) frameworks. NET Programmers can also build custom controls for ASP. Unlike user controls, these controls do not have an ASCX markup file, having all their code compiled into a dynamic link library (DLL) file.Such custom controls can be used across multiple Web applications and Visual Studio 2013 projects. NET uses a "visited composites" rendering technique.
During compilation, the template (.aspx) file is compiled into initialization code that builds a control tree (the composite) representing the original template.
Literal text goes into instances of the Literal control class, and server controls are represented by instances of a specific control class.