Getting Started with ASP.NET
ASP.NET is a new Internet programming technology from Microsoft that applies a more streamlined, object-oriented approach to building dynamic Web applications. With existing Active Server Pages technology, server-side code is intermingled and interspersed with client-side HTML. This often results in large, complex pages of code, where following the logic of the program can be difficult at best, especially if you are new to programming.
In this hour, you will learn more about what ASP.NET has to offer. To be more specific, you will learn
What ASP.NET is
What the system requirements are to implement an ASP.NET application
How to install the ASP.NET Framework on your system
What tools can be used to create ASP.NET applications
How to create an ASP.NET page
How to view the output of your ASP.NET pages
What Is ASP.NET?
In the early days of Internet Web site design and development, technologies were limiting. Static HTML pages served up the necessary information that a person wished to convey to his audience. Because technologies were more limiting back then, it was easier to get away with a site that was not as interactive as it needed to be. Nowadays, however, it is important to learn how to build dynamic, interactive Web sites, especially with the increasing use of multimedia elements such as Flash and Shockwave and the development of e-commerce and e-business sites that require database integration.
To meet this need, Microsoft created a Web-development platform called Active Server Pages, or ASP. ASP was widely used and accepted throughout the industry because most developers could utilize their existing Visual Basic or VBScript skill sets when developing Web applications.
To overcome these problems and many others, Microsoft has introduced ASP.NET—its next-generation Web development environment. If you have experience in programming applications, you will find that the ASP.NET Framework is very similar to building client/server applications. Even if you've never written a line of code in your life, you will find that ASP.NET is a relatively easy programming language to learn.
Is ASP.NET Browser Specific?
ASP.NET is a browser-independent programming model. ASP.NET will run on the latest versions of Internet Explorer and Netscape Navigator, as well as on other widely used browsers, such as Opera. Also, ASP.NET applications will gracefully downgrade to older versions of Internet Explorer and Netscape Navigator. This means that the vast majority of users on the Internet will be able to use your Web applications without you needing to write browser-specific code. This feature takes a great burden off the shoulders of current Web developers, although it is still important to be aware that not all browsers accept Dynamic HTML (DHTML) in the same way. For instance, Netscape Navigator versions 4.0 through 4.75 do not allow text properties, like color and font, on the page to be changed unless the page is reloaded in the browser. Internet Explorer versions 4.0 and higher, on the other hand, do allow text properties to be changed on the page. These inconsistencies, and many others, still need to be considered when writing client-side code.
What Programming Languages Can Be Used with ASP.NET?
The .NET Framework specifies that applications can be written in any programming language that supports the Common Language Runtime (CLR). The Common Language Runtime translates any CLR-compliant application to Microsoft Intermediate Language (IL). This intermediate-level code is then compiled for the platform where it will be executed. This simple process allows you to create an application in one language that can be used on any operating system using CLR. Furthermore, you can take an application that is written in one programming language and use it in an application that is written in a completely different programming language. No longer do you have to learn a completely different programming language whenever a new technology is released.
For the latest version of the .NET Framework, Microsoft is releasing four different languages that can be used to write CLR-specific code. These languages are Visual Basic.NET (also known as VB.NET), C# (pronounced C-sharp), C++.NET, and JScript.NET. Third-party languages are also being developed such as Perl, Smalltalk, and Cobol, with more languages expected to join the list as the technology becomes more prevalent. Here's a brief description of each of these Microsoft languages:
Visual Basic.NET: VB.NET is a relatively easy programming language to learn. It is considered a high-level programming language, which means that its syntax is close to human languages and not similar to machine languages, such as Assembly. Of the programming languages mentioned in this section, VB.NET is probably one of the easiest languages to learn. For this reason, all the code examples in this book will be written in VB.NET.
C#.NET: C# is a simple, modern, object-oriented, type-safe programming language derived from C and C++. C# aims to combine the high productivity of Visual Basic and the raw power of C++. This language is geared toward more accomplished developers who are used to the somewhat-cryptic structure of C++. Beginning developers are advised to start with Visual Basic and then move on to C#.
Visual C++.NET: Visual C++.NET is the next iteration of Microsoft's existing Visual C++ programming language, which is a powerful, object-oriented programming language. Typically, this language is used to create very complex and sophisticated applications.
JScript.NET: JScript is a powerful scripting language targeted specifically at the Internet. It is also the first scripting language to fully conform to ECMAScript—the Web's only standard scripting language. This language is similar in syntax to C# and C++, although it is a little easier to implement.
What Is Needed to Run ASP.NET?
In order to run ASP.NET pages, you will need to configure a computer with the .NET Framework installed. As of this writing, the .NET Framework is supported on Windows NT 4.0, Windows 2000, and Windows XP. However, Windows NT 4.0 with Service Pack (SP) 6a or Windows 2000 with SP 2 is strongly recommended. You will also need to install Internet Explorer 5.5 and Microsoft Data Access Components (MDAC) 2.6 as prerequisites to the .NET Framework. In addition, if you are not running Windows 2000, you must install Internet Information Server (IIS), known as Personal Web Server (PWS) in Win9X and Me. IIS 5.0 could be easily added to Windows 2000 Professional via Add/Remove Windows Components in the Control Panel. Make sure the IIS service has been started.