A comparison between ASP.NET 1.x and ASP.NET 2.0

ASP.NET 2003

ASP.NET 2005

During the compilation of applications for .NET 1.x, Visual Studio 2003 would automatically compile only certain file types such as ASP.NET pages, Web services, user controls, HTTP handlers, Resource files, and Global.asax class files. The rest of the files needed to be explicitly compiled before finally publishing your code to the web server.

In Visual Studio 2005, you no longer need to compile all the files into an assembly. The ASP.NET dynamic compilation engine allows to automatically compile applications, that includes .aspx, .cs, .vb files. That means, simply create an application and publish it.

A shared class consists of reusable source components in the code folder.

The new code-separation model extends the Compile-on-Demand feature to the classes bound to a Web page, but it does not stop there; helper classes can also take advantage of it. You can keep your helper classes and business objects in the App_Code folder. ASP.NET monitors the folder and compiles any new class file that is added or edited. The resulting assembly is automatically referenced in the application and shared between all pages participating in the site.

You should put only components into the App_Code folder. Do not put pages, Web user controls, or other non-code files containing non-code elements, into the App_Code subdirectory. All the files in the App_Code folder are dynamically compiled to a single assembly, named code.dll. The assembly has an application scope and is created in the Temporary ASP.NET Files folder, well outside the Web application space.

For modifying an application, you need to open the entire project, make changes, and need to recompile again to publish the code to the web server.

You just need to open the individual file which you want to make the changes, and publish the code to the web server without having to recompile.

The code-behind model requires an IIS virtual directory.

The code-behind model can directly access the local installation of IIS.

The code-behind model lacks support for FTP, local file systems, and direct IIS access.

The code-behind model has multiple ways to open Web sites.

It requires IIS on the development computer.

It already has a built-in Web server.

Unable to open individual pages outside the project.

Need not open the entire project; you can open individual pages outside the project, it is achieved through the compile-on-demand feature.

It requires explicit addition of files to the project.

It eliminates the need to explicitly add files to the project.

The compilation models of ASP.NET 1.x and ASP.NET 2.0 are built on completely different bases.

The new class-derivation model enables the page to define controls without the need to have protected members created in the inherited separation file, or to have explicit event definition.

Pages that use code separation take advantage of a feature known as Partial Classes. When the page runs, ASP.NET 2.0 dynamically creates and instantiates a class representing the page, and the compiler uses the CodeFile attribute in the @Page directive to find the file containing the code.

The Inherits attribute defines the name of the class that will be created, and by default, use the page name as the basis for creating the class name.

The @Page directive in ASP.NET 2.0 has several new attributes. These attributes allow developers to control new framework features such as personalization and theming. The Page class in ASP.NET 2.0 also has new properties, methods, and events.

Properties

The properties of the Page object fall into two distinct groups: intrinsic objects and page-specific properties. Intrinsic objects include references to environmental standalone objects such as Cache, User, and Trace. They also include references to the classic intrinsic objects that form the HTTP context, such as Session, Application, and Request. Page-specific properties are all the properties that affect or describe the state of the page, for example, IsPostBack, EnableViewState, and SmartNavigation.

The new properties of the Page class can also be categorized into either of the preceding groups.

The three important new properties are:

• ClientScript - Instance of the ClientScriptManager class that represents a separate object, and which groups all the methods working with the client-side scripts.
• Header.IPageHeader - The interface that represents the contents of the page's <head> block if this is marked as runat=server.
• Master - Gets the master page that determines the overall look of the page.

Methods

The Page class features several new methods, most of which are simply inherited from the base Control class.

Some of the important methods are:

• GetValidators - Returns the collection of all validator controls that belong to the specified group.
• SetFocus - Sets the input focus to a particular control contained in the page.
• RegisterRequiresControlState - Registers the specified control as one that requires control state management.

In the ASP.NET runtime, the life cycle of a page is marked by a series of events. In ASP.NET 1.x, based on user interaction, a page request is sent to the Web server. The event that is initiated by the page request is Init. After the Init event, the Load event is raised. Following the Load event, the PreRender event is raised. Finally, the Unload event is raised and an output page is returned to the client.

ASP.NET 2.0 adds quite a few new events to allow you to follow the request-processing more closely and precisely. These new events are discussed in the following table.

New Events in ASP.NET 2.0

Developers can dynamically modify the page output and the state of constituent controls by writing these events into the code.