Preface


Microsoft Visual Basic began its life back in 1991 as a kind of amalgamation of Microsoft's QBasic programming language and a graphical interface design program developed in part by Alan Cooper. Since then, it has become one of the most popular programming languages in the world.

The 10th anniversary of Visual Basic coincided with the announcement of Microsoft's new .NET platform, and with it a totally revised and revamped version of Visual Basic named "Visual Basic .NET." With the initial release in 2002, the language was streamlined and modernized, and many old "compatibility" elements were dropped from the language. Since that first release, VB.NET has been enhanced and improved through two more general releases (in 2003 and 2005).

Pre-.NET versions of VB included a "good try" implementation of standard object-oriented features, but they often came up short. Teamed with .NET, Visual Basic is now a fully object-oriented programming (OOP) language, with the inclusion of the long sought-after class inheritance feature, as well as other OOP elements. The 2005 release adds operator overloading to the language, something that was absent in the initial .NET version.

Before .NET, Microsoft's Component Object Model (COM) technology played a significant role in application development, especially when it became part of the foundation of Visual Basic 4.0. With the advent of .NET, COM begins to take its exit from the Windows programming stage, as .NET includes a new namespace-based component integration system. This is somewhat unfortunate, since Visual Basic developers have a lot of time and source code invested in COM components. As great as COM was, it was also complex, and there were numerous compatibility issues when sharing components between Visual Basic, Visual C++, and other languages that either produced or consumed these "ActiveX" libraries. All core compatibility issues are banished with .NET, and although you can still take advantage of your substantial investment in COM components through .NET's "interop" features, the enhancements available through .NET will certainly draw all developers eventually to abandon the COM system.

For developers who have made the switch from .NET, the best news of all is that Visual Basic is now an "equal player" with other languages, in terms of programming power and accessibility of Windows features and services. In the past, Visual Basic served as a "wrapper" that simplified and hid much of the complexity of Windows and its Application Programming Interface (API). Now, Visual Basic programmers have full and easy access to all features of the .NET and Windows platforms, just as Visual C++ and C# programmers do.

The extensive changes to the language and the introduction of the .NET platform make a reference guide to the Visual Basic language more essential than ever. At the same time, they make it easy to delineate this book's subject matter. This is a book that focuses on the language elements of .NET-powered Visual Basicon its statements, functions, procedures, directives, and objects.

This book provides essential information on the Visual Basic language for the .NET platform, but there are some things this book is not:

  • It is not a reference guide to Visual Basic for Applications (VBA), the programming language used in all of the major applications in the Microsoft Office suite, as well as in dozens of other third-party applications. VBA served as the core programming language in earlier versions of Visual Basic. However, VBA is not the programming language for the .NET versions of Visual Basic. Microsoft Office Version 12 (not named as of this writing) will include Visual Studio Tools for Applications (VSTA), a new .NET replacement for VBA.

  • It is not a reference guide to the .NET Framework Class Library. The Framework Class Library is discussed in these pages, and a number of its classes and their members are documented in this book's reference section. But that documentation just scratches the surface; the Framework Class Library consists of about 200 namespaces (one of which, incidentally, is Microsoft.VisualBasic, the namespace that defines many features of the Visual Basic language), several thousand types (including classes, interfaces, delegates, and enumerations), and an enormous number of members. In selecting the .NET Framework classes to document in this book, we've tried to focus on .NET elements that replace commonly used features in pre-.NET versions of Visual Basic, as well as on .NET elements that expand and enhance the productivity of Visual Basic developers.

  • It is not a reference guide to the attributes that you can apply to program elements. Chapter 9 introduces attribute-based programming, and there are entries for important language-based attributes in the reference section. But with hundreds of attributes available in the .NET Framework Class Library, only language-related attributes and the general-purpose attributes VB developers are most likely to use are documented in this book.

  • It is not a guide to developing full applications or components using Visual Basic or .NET. The text includes simple code fragments that illustrate relevant syntax and code usage, to demonstrate how a language element works. But it doesn't show you the big-picture activities, such as how to use the Windows Forms package to build a Windows application, how to develop a web application using ASP.NET, or how to implement a web service.




Visual Basic 2005(c) In a Nutshell
Visual Basic 2005 in a Nutshell (In a Nutshell (OReilly))
ISBN: 059610152X
EAN: 2147483647
Year: 2004
Pages: 712

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