User Controls vs Custom Controls
Microsoft Corporation is the world’s leading producer of computer software and hardware as well as Web applications. It dominated the home computer operating system market in the 1980s through MS-DOS.
Through the years it has not only lead in the computer office software market but has also entered into several other niches such as the video game industry and consumer electronics.
One of its products is the Web application framework ASP.NET. It is used in building Websites, applications, and services. Through the Common Language Runtime (CLR), it lets programmers write ASP.NET code using whatever .NET language.
In creating a Web page, ASP.NET uses .ASPX extensions that contain XHTML markup and Web and user controls where programmers put content for the Web page using a code-behind model.
User controls are summaries or condensed sections of registered Web pages which are used as controls in ASP.NET. They are made as ASCX markup files and use the same methods as that of HTML and web server controls.
They are designed to be reusable and provide users with an easier way to reuse and partition user interfaces in ASP.NET web applications. The user controls page is collected and stored in memory for future requests.
User controls are designed only for use in single applications and can cause maintenance problems if used in more than one application. Since it contains static data, writing does not need a lot of design, and it is best for use in a fixed layout such as in the making of headers. Writing in custom controls, on the other hand, is more complex and needs several codes since it is not designer supported as in the case of user controls. They are best used for dynamic content.
Custom controls are collected code elements which execute on the server and disclose the object model to present the markup text like HTML as normal Web form. They can be used in multiple Web applications.
As they are designed for use by more than one application, distribution will not cause any maintenance or redundancy problems. It even makes maintenance a lot easier with the installation of a single copy in the global assembly cache to be shared between applications.
Although they are difficult to make, custom controls are easy to use and can be added in the toolbox which is not possible with user controls which need to be installed in separate copies for each application when shared between applications.
Summary:
1.User controls are summaries of registered Web pages which are used as controls in ASP.NET while custom controls are code elements which are compiled for use in Web applications.
2.User controls can only be used in single applications, and to share them users must install separate user controls for each application while custom controls are designed for use in multiple applications.
3.User controls can cause maintenance problems while custom controls do not.
4.Custom controls are difficult to make but are easy to use while user controls are easy to make but can be more complex to use.