Sams Teach Yourself Visual Basic .NET in 21 Days - Softcover

Mackenzie, Duncan; Sharkey, Kent

Softcover

ISBN 10: 0672320665 ISBN 13: 9780672320668

Publisher: Sams, 2001

Synopsis

Sams Teach Yourself Visual Basic.NET in 21 Days provides readers with 21 structured lessons with step-by-step guidance to real-world tasks. Each chapter also contains exercises that reinforce the lessons learned in each chapter. Tips, Notes, and Cautions provide additional advice from the authors on how to get up-to-speed and programming quickly with Visual Basic.NET.

About this title

About the Author

Duncan Mackenzie is an MCSD, MCSE, and MCT who works for the MSDN (http://msdn.microsoft.com) group at Microsoft out of Redmond, Washington. He is an excited Visual Basic .NET programmer who has an annoying habit of writing the occasional article. Duncan also has been active as a Visual Basic trainer and has taught many courses ranging from intermediate to advanced VB programming. Duncan has written and collaborated on a number of books on Microsoft technologies, including Platinum Edition Using Visual Basic 6.0 and Word 2000 VBA Programmer's Reference. He also speaks at many conferences focused on Microsoft development.

Kent Sharkey is an MCSD, MCSE, MCT, and MCP+SB. He currently works at Microsoft as a Technical Evangelist within its .NET Solutions Group, his current assignment being the .NET Framework and Visual Studio .NET. Before joining Microsoft, Kent had many years of experience as a trainer and consultant, concentrating on architecting and writing n-tier applications using Visual Basic. He has written and collaborated on a number of books on Visual Basic, including MCSD Fast Track: Visual Basic Exam 70 Ð175; MCSD Fast Track: Visual Basic Exam 70 Ð176; MCSD Fast Track: 4 in 1; and Beginning Visual Basic 6.0 Application Development. He is a regular speaker at various developer conferences focused on Microsoft development.

Excerpt. © Reprinted by permission. All rights reserved.

(b)Building the User Interface with Web Forms
While most traditional applications used the Windows Forms model, creating Web or browser applications continues to become more and more important. Today, we will look at how we can create browser-based user interfaces. The tools within Visual Basic.NET assist the developer in easily creating web pages that provide fairly rich user interfaces across any browser type. In particular, today we will focus on:
* How the web programming model differs from the traditional Windows based model
* Using standard Web Forms controls
* Using advanced Web Forms controls
* Using the Validator controls

(c)The Web Programming Model
Some days I think that everyone in the world is on the Internet, especially when my access speed is in the painfully slow mode as everyone is browsing, chatting and e-mailing (but not doing business). (As a tip, I somehow find that the best time to be online is during Star Trek - probably just a co-incidence). Obviously, one of the most important, or at least popular, aspects of the Internet is the World Wide Web (WWW). However, there has generally been a shortage of really good programming tools for creating WWW 'programs', rather than just simple WWW pages. This is at least partly because creating applications for the Web is different from creating applications for a desktop computer, where you have more control. In addition, web applications must deal with the network more frequently.

So, what is the "Web Programming model"? It is just a term used to describe how you can design, or architect, a program that uses web pages in a browser as a way to allow the user to enter information. These web pages are designed using HTML (HyperText Markup Language - we won't be covering HTML in this book, but there are plenty on the market). The browser is an application that knows how to read HTML and display it on the screen. Usually (but not always), most of the work of the application is done on the web server. The Web Server is another program running on a computer that knows how to return HTML on demand. In Windows NT and 2000, this program is called Internet Information Server (IIS). The information is carried between the browser and the server using a protocol, or language, called HTTP (HyperText Transfer Protocol).

In the 'beginning' of the World Wide Web, web pages were static. That is, they never really changed. Things got more interesting when people started to create dynamic, or changing, web pages. This was the dawn of the 'Web Program'. With 'Web programs', rather than simply returning the same HTML every time, the web server may perform some task and return HTML appropriate to the result. For example, the user might request the sales information for a particular date range. This information is passed to the server. The server in turn might look that information up in a database, and then write the HTML to display it to the user.

Web programming model.
Alternately, the server (or web page designer) might add programming information to the page itself, creating a page that is a little program in its own right. This is often called Dynamic HTML (or DHTML). With DHTML, the page includes some JavaScript (a programming language, like Visual Basic.NET that runs in web pages) or other language. The code can run in the browser without needing to send any information back to the server.

There are a variety of techniques that can be used to create a web program. Some of the most common techniques used in the past have been ASP (Active Server Pages), Perl (another programming language) or JSP (Java Server Pages). The technique used by Web Forms is an improvement of ASP, ASP.NET.

(d)ASP.NET
ASP.NET is Microsoft's name for its improved version of ASP. While ASP was a very easy method for building dynamic web pages, it had some problems that ASP.NET is designed to solve:
* ASP often required too much code to get something done. ASP.NET requires less code (often much less code) for common programming tasks.
* ASP still suffered from the limited number of controls that HTML suffers from. ASP.NET adds the idea of "server-side controls" that can generate HTML appropriate to the browser requesting it. While these controls are just HTML in the browser, they can represent a great deal of HTML and code, saving you from having to write it.
* ASP only allows you to program in a language such as VBScript. VBScript is interpreted at run time, not compiled like real Visual Basic. ASP.NET allows you to write their web pages in real, fully compiled Visual Basic.NET.
ASP.NET is also designed to solve other problems with ASP that aren't appropriate to our discussion of building user interfaces, such as improvements to scalability and memory use.

Edition details

• Publisher: Sams
• Publication date: 2001
• ISBN 10: 0672320665
• ISBN 13: 9780672320668
• Binding: Paperback
• Language: English
• Edition number: 1
• Number of pages: 688