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 Design
a user interface. Set properties. Write code. Nothing gets more people
started building Windows applications faster than the Visual Basic
programming language. So it's easy to understand why bookstores' shelves
groan with the weight of books claiming to make you a Visual Basic programmer
by yesterday.
Writing Windows applications has become an enormously complicated task, but
Visual Basic manages to hide much of that complexity. While it remains
hidden, it doesn't go away. Writing good applications in Visual Basic doesn't
come as easily as an afternoon of reading. Writing them takes hard-won
skills. This article can't take you from here to there, but it can get you
started, and it does give you a roadmap for the hardest part of the journey:
the beginning.
 Some History & Perspective
How did Microsoft end up with a product called Visual Basic? Basic
comes from the computer language of BASIC (Beginners All-Purpose Symbolic
Instruction Code), which has cast its shadow upon more programmers than any
ot 151i811b her code in the short history of computing. Since the development of BASIC
in 1964, it has held a central role in programming. The BASIC language has
been in widespread use for both casual and corporate developers. Even in
Microsoft's own company history, BASIC has endured in one platform or
another. A form of BASIC was Microsoft's first product, and the company has
produced a version of it ever since.
Visual Basic is yet another result of Microsoft's adoption of the BASIC
language. It doesn't take too much exposure to realize that in application
development, Microsoft uses the term "visual" to refer to the method used to
put together a program's user interface. This term definitely has meaning in Visual
Basic. Rather than writing voluminous code to describe the placement and
appearance of interface elements, Visual Basic simply lets you choose and
place prebuilt components on-screen.
While Visual Basic has its advantages and is dramatically different from the
BASIC language of yore, it is still saddled with baggage and bad habits from
the past. Still, it has Microsoft's full support and backing. In fact,
Microsoft inextricably intertwined it with its Windows operating system. Due
to its simple syntax and ease of use, many developers use Visual Basic to
create Windows applications or incorporate new elements into their existing
applications. The typical application developed with Visual Basic, however,
is created by corporate developers for internal consumption. In this domain,
its low learning curve and quick development cycle more than make up for its
design and performance flaws.
The Different Faces Of Visual Basic
Before addressing the basics of Visual Basic, it's important to
set the scope of discussion. Visual Basic is a family of Microsoft products
and languages. There are other forms of BASIC around, but they are miniscule
compared to the Microsoft family. Visual Basic is a family because Microsoft
uses variants of the BASIC language in different contexts. The major family
members are Visual Basic, Visual Basic for Applications (VBA), and Visual
Basic Scripting Edition (VBScript).
Visual Basic. The Visual Basic format is a standalone tool.
You can use it to create software components, including executable programs,
COM components, and ActiveX controls. It is most useful when you are building
an application or component, especially a graphical one, from scratch.
VBA. This version provides much of Visual Basic's power in
the context of an existing application such as Microsoft Excel and Word. It's
the natural tool for customizing such software. Microsoft's site says Visual
Basic for Applications 6.0 is a core Office 2000 component and is integrated
into each Office application.
VBScript. You can use this lightweight version of the Visual
Basic language for scripting. Scripting generally means that the source code
is compiled into an executable format only at the time the program is run.
Microsoft specifically designed VBScript for use on Web pages. It lacks an
integrated development environment.
This article focuses on Visual Basic, the standalone development tool of
applications. One significant benefit of learning Visual Basic is that the
language and its tools are significantly similar across all three contexts.
While the concepts addressed by Visual Basic are more extensive than for the
other two versions, the language syntax is similar, and there is a rich
crossover so a large amount of the effort you invest in learning Visual Basic
will also carry over.
The Latest Editions
Visual Basic 6 is the current incarnation of Visual Basic. While
the older versions of Visual Basic (especially version 5) are still viable
tools for producing Windows applications, it is generally best to stick with
the latest tools despite the upgrade expense.
Microsoft continually rolls out enhancements for its language products so
that users can take advantage of new features in its operating systems. It
describes Visual Basic 6 as ready for Windows 2000. Concrete improvements in
this version include new database access tools and a high-performance native
code compiler. The native code compiler adds fast code execution to
interactive development.
In addition to choosing a version, you must also decide which of three
editions suits your situation.
Visual Basic Learning Edition. This entry-level tool,
targeted at hobbyist or novice programmers, contains all the basic controls,
such as buttons, grids, and text boxes, as well as the all-important
Microsoft Developer Network (MSDN) Library. The library contains reams of
articles and other references essential for developers.
Visual Basic Professional Edition. This edition of Visual
Basic is considerably more expensive, and it's primarily for professional and
corporate developers. It includes additional components and tools aimed at
database and Web development.
Visual Basic Enterprise
Edition. This advanced edition, designed for teams of multiple
corporate developers, will probably cost you more than your mortgage payment.
To get help in choosing the right edition, see Microsoft's Visual Basic Web
site (https://msdn.microsoft.com/vbasic).
Visual Basic 101
While you can follow a simple recipe and create your first
application in literally three minutes, mastering this beast is going to take
months of meticulous dedication. The concepts required to effectively use
Visual Basic can be broken down in many different ways. Most of the books on
this subject choose their own method of organization. One simple division is
to consider language concepts and application concepts.
Language concepts relate to learning the syntax and
semantics (loosely interpreted, the form and meaning) of the Visual Basic
language itself. Application concepts are concerned with the
organization of an application and the libraries of functions and objects
used to create your finished product. Application concepts build on your
understanding of the language concepts.
For example, consider the skills needed to build a cathedral. Language
concepts are equivalent to skills such as shaping stone and laying stones on
each other. Application concepts are equivalent to designing blueprints
calling for buttresses, transepts, and vaults. You can't understand the
latter until you've mastered the former.
Language concepts. Unfortunately, there is not enough space
in this article to cover the full syntax of Visual Basic, but it is not
particularly difficult to learn. People familiar with programming in general
should be able to get started immediately.
Conditional statements include a familiar, though wordy, if-this-then-this
construct, as well as a "case statement" for times when your program logic
has to choose from among more than two alternatives. The "go-to" and "go-sub"
statements are remnants of darker days for BASIC; most people avoid them
today. Visual Basic's four looping constructs should be enough for anyone's
stylistic preferences.
Visual Basic also contains a stable full of built-in data types for storing
values such as numbers, characters, and strings. In this article, we've only
scratched the surface of the language concepts. Microsoft's program
documentation or a strong reference book such as "Pure
Visual Basic" by Dan Fox are good places to look for more details.
Application concepts. These concepts describe the basic
building blocks of a Visual Basic program, such as windows, forms, controls,
classes, and modules. Programming a Visual Basic application begins with
creating the program's visual interface, which you build by assembling forms
and controls.
Windows play a central role in Microsoft's modern operating
systems. They provide a foundation for interacting with users. Forms
in Visual Basic are analogous to windows. A form is an object with properties
defining its appearance. It also has methods defining its behavior as well as
events defining the ways in which it interacts with users. Visual Basic makes
it easy to set a form's properties. And by writing Visual Basic code to
respond to events, it is relatively easy to customize the object for your
application.
Controls are user interface objects embedded into a form. A
dialog box provides a simple example. The dialog box itself is a form
containing a number of controls such as buttons, text, checkboxes, and input
fields. Controls, like forms, have properties, methods, and events, each
suited to the particular type of control. For example, a button responds to a
"click" event, but a text-label control does not. By writing code that
responds to a "click" event, a Visual Basic programmer attaches the basic
logic of the program to its user interface.
Modules are the containers for Visual Basic code. The form,
standard, and class modules are common to all editions of Visual Basic. Form
modules (using the .FRM file extension) are the basis of most Visual Basic
applications. Standard modules (.BAS) are not associated with a particular
form and can be reused in many applications; as such, they are containers for
generic declarations and procedures that are useful beyond the scope of a
single form. Class modules (.CLS) are the basis for object-oriented
programming in Visual Basic. The Professional and Enterprise editions include additional
module types.
Templates are a concept added to Visual Basic 5. A template is essentially a standard form or object
created once and reused in a number of applications. By reusing the same
templates, such as one for a log-in dialog box, developers can enforce a
consistent look and feel to all their applications. Everyone wins with
templates: Developers do not have to continuously write and maintain similar
code, and users only have to learn a single style for common forms.
The Integrated Development Environment
For the Visual Basic beginner, simply firing up the development
environment can be a little intimidating. First, you'll see the
complicated-looking New Project dialog box, complete with colorful icons and
multiple choices. Fear not, getting comfortable with the Visual Basic IDE
(Integrated Development Environment) isn't difficult, and if you understand
the application concepts described above, it's that much easier. Half of the
fun of learning Visual Basic is getting to know how to use the IDE, which
serves as home to your development efforts.
The Project area is a control in the upper-right corner that displays all the
forms and modules in your current project. A project is a set of files
(containing application objects described above) that you're using to build
an application or component.
The Properties window, found directly beneath the Project area, is probably
the most important control. It exposes all the properties of the currently
selected form or control. Property names display on the left, and the current
value displays on the right. By changing a property value, you change your
application's look or behavior. In the lower-right corner, the Form Layout
window is where to set the Desktop position where the forms in your
application will appear.
On the left side of the IDE is the toolbox. This includes a palette of
controls, or user interaction objects, that you can incorporate into
programs. The central space in the IDE is, by default, reserved for the Form
window, which is active when you have a project open. It lets you design and
customize the interface of your application. The Code window below is an
editor where you enter application code.
Other windows (such as the Immediate, Locals, and Watches windows) come into
play while debugging your application. Use the View menu to toggle all of
these windows on and off.
No tour of the IDE would be complete without covering a critical tool, the
Object Browser. Press F2 to activate the Object Browser, which lists objects
available for use in our project. Use the Object Browser to quickly navigate
through your source code and see what methods and properties are available in
your forms and controls, as well as in other applications.
Master The Art
Building simple Windows applications with Visual Basic is easy,
learning to master Visual Basic takes real time and effort. Probably the most
common method for building skills is to buy the program and a do-it-yourself
book.
You can broaden your experience with community college classes and continuing
education courses that target Visual Basic skills. Taking a course means
someone is available to directly field your questions. Corporate courses and
seminars are usually more expensive but can be an effective solution for
corporate developers.
You can search the Web to find Visual Basic users groups near you. Search for
"vbug" or "Visual Basic Users Group" and your
location.
Other resources include Web pages such as https://www.vbexplorer.com
and https://vbwire.com, as well as newsgroups
such as comp.lang.basic .visual.announce
and comp.lang.basic .visual.database.
This overview is the first step toward joining the ranks of Visual Basic
programmers. The rest is up to you. Don't forget to have fun along the way.
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