The Flavors of ASP.NET: Web Forms, and Web Pages

ASP.NET offers frameworks for creating web applications: ASP.NET Web Forms and ASP.NET Web Pages. All frameworks are stable and mature, and you can create great web applications with any of them.

Each framework targets a different audience or type of application. Which one you choose depends on a combination of your web development experience, what framework you’re most comfortable with, and which is the best fit for the type of application you’re creating. All three frameworks will be supported, updated, and improved in future releases of ASP.NET.

Here's an overview of each of the frameworks and some ideas for how to choose between them.

ASP.NET Web Forms (.aspx pages)

The Web Forms framework targets developers who prefer declarative and control-based programming, such as Microsoft Windows Forms (WinForms) and WPF/XAML/Silverlight. It offers a WYSIWYG designer-driven (drag-and-drop) development model, so it's popular with developers looking for a rapid application development (RAD) environment for web development. If you’re new to web programming and are familiar with the traditional Microsoft RAD client development tools (for example, for Visual Basic and Visual C#), you can quickly build a web application without having expertise in HTML and JavaScript.

In particular, the Web Forms model provides the following features:

• An event model that exposes events which you can program like you would program a client application like WinForms or WPF.

• Server controls that render HTML for you and that you can customize by setting properties and styles.

• A rich assortment of controls for data access and data display.

• Automatic preservation of state (data) between HTTP requests, which makes it easy for a programmer who is accustomed to client applications to learn how to create applications for the stateless web.

Web Forms works well for small teams of Web developers and designers who want to take advantage of the large number of components available for rapid application development. In general, creating a Web Forms application requires less programming effort than creating the same application by using the ASP.NET MVC framework. The components (the Page class, controls, and so on) are tightly integrated and usually require less code than ASP.NET MVC applications. However, Web Forms is not just for rapid application development. There are many complex commercial apps and app frameworks built on top of Web Forms.

Because a Web Forms page and the controls on the page automatically generate much of the markup that's sent to the browser, you don't have the kind of fine-grained control over the HTML that the other ASP.NET models offer. An event-driven, control-focused model hides some of the behavior of HTML and HTTP. For example, it's not always possible to specify exactly what markup might be generated by a control.

The Web Forms model doesn't lend itself as readily as ASP.NET MVC to patterns-based development, separation of concerns, and automated unit testing. If you want to write code factored that way, you can; it’s just not as automatic as it is in the ASP.NET MVC framework. The ASP.NET Web Forms MVP project shows an approach that facilitates separation of concerns and testability while maintaining the rapid development that Web Forms was built to deliver. As an example of this in action, Microsoft SharePoint is built using Web Forms MVP.

ASP.NET Web Pages (.cshtml and .vbhtml files)

ASP.NET Web Pages targets developers who want a simple web development story, along the lines of PHP. In the Web Pages model, you create HTML pages and then add server-based code to the page in order to dynamically control how that markup is rendered. Web Pages is specifically designed to be a lightweight framework, and it's the easiest entry point into ASP.NET for people who know HTML but might not have broad programming experience — for example, students or hobbyists. It's also a good way for web developers who know PHP or similar frameworks to start using ASP.NET.

Like Web Forms, Web Pages is oriented toward rapid development. Web Pages provides components called helpers that you can add to pages and that let you use just a few lines of code to perform tasks that would either be tedious or complex. For example, there are helpers to display database data, add a Twitter feed, log in using Facebook, add maps to a page, and so on.

Web Pages provides a simpler approach than Web Forms. If you look at a .cshtml or .vbhtml file, you can generally think of the logic as executing top-to-bottom in the file, as you would with PHP, SHTML, etc. And because .cshtml and .vbhtml files are essentially HTML files that have additional ASP.NET code in them, they lend themselves easily to adding client-side functionality via JavaScript and jQuery.