 The magazine of the Melbourne PC User Group Seeing the Basics: VB 5.0 - Component-driven development Tony Stevenson |
This fifth release of Visual Basic marks another significant milestone in
its short, but rich history.
It first appeared in mid-1991, and is now regarded by many in the software industry as the most popular
programming language ever released (at least for PCs.) It is estimated that more than 3 million developers
use it worldwide, and that number is growing daily.
Version 1.0 of VB revolutionised the way Windows applications were designed and built. Its visual approach
not only made it easier to write Windows programs, it also put the fun and creativity back into
programming.
Initially, Visual Basic was regarded by some of the more traditional programmers as just being "a bit of a
toy". However, they were undoubtedly proven wrong when, by version 3.0, Visual Basic had cemented itself as
the preferred Windows development tool for many seasoned Windows programmers.
The release of Visual Basic 5.0, I believe, represents two major, but interconnected, shifts in the direction
of PC programming: component based software, and net-aware applications.
Component-based software (CBS)
Firstly, VB 5.0 shows that it is not only possible, but that it is also highly desirable, to adopt a
component-based approach to building applications.
One of the major advantages of Visual Basic has always been its use of controls, which are pre-packaged
functioning objects that can be placed on the forms (or windows) contained within applications. Examples of
some of the more basic controls are command buttons, check boxes, scroll bars, etc.
However, as the popularity of VB increased, both Microsoft itself and third party vendors released more
sophisticated controls that developers could simply plug into their programs (and which required only a
minimal amount of coding). So it became both possible and easy to incorporate complex functionality such as
spreadsheets, word processors, spell checkers, schedulers, and so forth, into Windows programs.
Visual Basic 5.0 has further extended this concept of controls to the practice of component-based software
(one of the manuals contained in this release is titled "Visual Basic Component Tools Guide.")
Building software out of components saves an incredible amount of time. Because components come straight out
of the pack ready to use, there is no need to write code for each required function (and then to laboriously
and exhaustively test it).
And one of the most exciting new features in this release of VB is that developers now have the power to
create their own controls (if so desired). Despite the wide number of components available, there will be
occasions when there will be a need to develop a component with unique functionality.
Being able to create components also means that they can be reused in other applications. Such reusability,
though long promised as one of the major advantages of object oriented programming, has, until now been a lot
more difficult to achieve in a practical sense.
Net-aware applications
Despite the gloomy predictions of some, the Internet is here to stay. Whilst undoubtedly the information
superhighway contains a lot of material that can only be described as rubbish and of little real value, other
information sources are no different (if you disagree, next time you are in a bookshop or newsagent do a
quick survey of the titles available).
But there are also tremendous opportunities to be had by tapping into the vast resources offered by the
Internet and particularly the World Wide Web.
A new, and growing trend in the development of personal computer applications is the blurring (or breaking
down) of the line separating traditional desktop and communications programs. Users today still want the
power and flexibility offered by the PCs sitting on their desks, but they also want to be able to view,
download, and transmit information on the Internet as well.
One of the significant developments with Visual Basic 5.0 is that it now allows for this type of information
integration.
VB 5.0 editions
Visual Basic 5.0 is available in three different editions.
- The Learning Edition, referred to as the Standard Edition in previous releases
- The Professional Edition, which is the edition that many home-based or small to medium business developers will use
- The Enterprise Edition, ideally suited to those developers in large organisations and corporations where a team-based approach is used to design and write VB applications
VB 5.0 is packed with new features, which this column will be exploring over the next few months. Just some of them are a native code compiler; the use of ActiveX technology (which forms the foundation of component programming); more than a dozen new wizards (wizards are electronic helpers that automate various development tasks); the inclusion of functionality to create ActiveX controls; extensions to the development environment such as Statement Builder, AutoComplete, and QuickTips; plus much more.
Loading VB 5.0 onto your machine
Because VB 5.0 is now a 32-bit development environment, its system requirements are as follows (this list is for the Professional Edition):
- 486 DX/66 MHz processor or higher (Pentium or better is recommended)
- MS Windows 95, Windows NT Workstation version 4.0 (Service Pack 2 recommended), or Windows NT Workstation version 3.51 (with Service Pack 5)
- 12 MB RAM for Windows 95 or Windows NT Workstation 4.0 (16 MB recommended), or 24 MB for Windows NT Workstation 3.51
- Hard disk space: 30 MB (minimum installation) or 115 MB (complete installation) or 220 MB (to install online documentation)
- CD-ROM drive
- VGA (or higher resolution) monitor.
In next month's issue of Seeing the Basics, we will look at two books that offer alternative, but both very effective, ways of learning the new features available in this latest release of VB.
VB 5.0 Web site
A lot more information about this exciting release of Visual Basic can be found at the Microsoft web page: http://www.microsoft.com/vbasic/
About the author
Tony Stevenson has recently completed a Masters in Computing by Research at Monash University in which his thesis concentrated on a component-driven approach to software development using Visual Basic.
Reprinted from the June 1997 issue of PC Update, the magazine of Melbourne PC User Group, Australia
