INTRODUCTION TO ASP.NET

ASP.NET is a programming framework developed by Microsoft for building powerful Web applications. Web Servers The previous version of Active Server Pages was ASP 3.0. ASP.NET and ASP 3.0 can both run on Internet Information Server (IIS) 5.0 with Windows 2000 and Windows XP. You can have your ASP.NET and your ASP 3.0 applications run on the same server. If you use Windows 95, 98, ME, or NT, and you want to run ASP.NET applications, you can install Windows NT or XP in addition to your other operating system by creating a dual-boot machine. This will enable you to run two operating systems on one machine, giving you the ability to run ASP.NET and keeping your original operating system intact. You will have to devote around 5GB of disk space to install the operating system (OS), the .NET Framework SDK, and any other supporting applications, such as SQL Server 2000. To separate the files associated for each OS, you should create a separate partition for the new OS. Versions The ASP.NET Framework is supported on Windows 2000 and Windows XP. ASP.NET applications will run on IIS 5.0 for these operating systems. Web Services is supported on all platforms supported by the Microsoft .NET Framework SDK, except Windows 95. Windows XP, Windows 2000, Windows NT 4 with Service Pack 6a, Windows ME, Windows 98, Windows 98 SE, and Windows 95 all support the Microsoft .NET Framework SDK. Language Support ASP.NET has built-in support for three languages: Visual Basic (VB), C#, and JScript. You can install support for other .NET-compatible languages as well.

Tools Microsoft designed ASP.NET to work with WYSIWYG HTML editors and other programming tools. Or, you can even use a simple text editor like Notepad. The Notepad text editor is used in this book’s code samples. If you want more support from your development environment for coding, you can use Microsoft Visual Studio.NET. Using a tool such as Microsoft Visual Studio.NET enables you to take advantage of other features such as GUI support of drag and drop Server Controls and debugging support. Web Forms ASP.NET Web Forms gives you the ability to create Web pages on the .NET platform. Web Forms enable you to program against the controls that you put on your Web pages. You can either use a Server Control that is built into ASP.NET or create your own custom Server Controls. These Server Controls are used for controlling HTML tags on a Web page. By using Web Forms, you can build user interface code as effectively as your Business Services code, reusing and packaging the code in a well-designed manner. Web Services ASP.NET Web Services gives you the ability to access server functionality remotely. Using Web Services, businesses can expose their data and/or component libraries, which in turn can be obtained and manipulated by client and server applications.Web Services enable the exchange of data in client-server or server-server scenarios, using standards like HTTP and XML messaging to move data across firewalls.Web services are not tied to a particular component technology or object-calling convention. As a result, programs written in any language, using any component model, and running on any operating system can access Web services. State and Application ASP.NET provides a simple framework that enables Web developers to write logic that runs at the application level. Developers can write this code in either the global.asax text file or in a compiled class. This logic can include application-level events, but developers can easily extend this framework to suit the needs of their Web application. ASP application code, written in the global.asa file, is supported in ASP.NET. You can simply rename global.asa to global.asax when upgrading from ASP. Data Access Accessing databases from ASP.NET applications is a common technique for displaying dynamic information to Web site visitors. ASP.NET makes it easier than ever to access databases for this purpose and provides for managing the data in the database. Performance A big difference between ASP 3.0 and ASP.NET is how your code is run on the server. With ASP.NET, your code is compiled into executable classes. With ASP 3.0, code often needs to be interpreted. With ASP 3.0, any serverside code is most likely going to have to be interpreted by the Web server, unless it is cached. If you want to avoid interpreted code in ASP 3.0, you need to put the code into a COM component. Power With ASP.NET, you now have access to the common language runtime (or CLR). Running on the CLR gives access to many of the features available in the .NET Framework, such as debugging, security, data access, language interoperability, and more. Configuration ASP.NET configuration settings are stored in XML-based files, which are text files easily accessible for reading and writing. Each of your applications can have a distinct configuration file. You can extend the configuration scheme to suit your requirements. Security The .NET Framework and ASP.NET provide default authorization and authentication schemes for Web applications. You can easily remove, add to, or replace these schemes depending upon the needs of your application. Migration from ASP to ASP.NET Simple ASP pages can easily be migrated to ASP.NET applications. ASP.NET offers complete syntax and processing compatibility with ASP applications. Developers simply need to change file extensions from .asp to .aspx to migrate their files to the ASP.NET framework. They can also easily add ASP.NET functionality to their applications with ease, sometimes by simply adding just a few lines of code to their ASP files.