Working with CPUs

The first step in writing a successful computer program is to decide what you actually want to accomplish. That is not the same as deciding what you want the computer to do! Look at this subtle difference: If you are designing a home stereo system, the end goal is not for the system to play music; it is for the system's owner to enjoy music played by the system. Too complex a user interface to the system may, for many users, get in the way of that goal.

A Little Visual Basic History

The BASIC language was invented in 1964 by graduate students at Dartmouth College in Vermont. This was a long time ago. It was a different world, then.

Working with the IDE

Not that many years ago, programmers had to also be jugglers.

In addition to the obvious—juggling job schedules, project schedules, personal schedules, and softball practice, programmers also had to manage all the files that made up their projects, and the compiled versions of those files, and work out dependency lists that made sure all the components that needed to be re-compiled after each code change, were re-compiled—but that others weren't, because that would take too much time. We also had to keep track of code editors, resource editors, resource painters, compilers, linkers, librarian systems, and more.

Working with Projects

A project is defined as all the modules and supporting files that contribute to the finished program, including one file that ties all the other pieces together. That file is called the project file.

Working with Modules

If you have been programming in the "linear" (non-object-oriented) fashion for years, you may wonder—perhaps with some trepidation—how big a change object-oriented programming will bring. To ease your concerns, let's look at the linear code modules that can contribute to some Visual Basic programs. Also remember that, each of your object-oriented components will be built up of linear snippets! So, on a line-by-line basis, object-oriented programming isn't so different from linear programming, after all.

Working with Forms

Forms are the primary unit of construction of a Visual Basic application. A form is a platform upon which user interface interactions are based. They provide a base on which controls such as buttons and list boxes can be placed, which the user manipulates directly.

Working with Colors and Graphics

In Windows, colors are represented (as is everything else) by numbers—specifically, 24-bit numbers. The 24 bits are divided into three sets of 8 bit values, one each for red, green, and blue intensities. As it turns out, virtually any color can be represented as combinations of red, green and blue.

Working with Controls

Among the toolbars and dockable views that usually appear when you start up Visual Basic, one is called the Toolbox. This toolbar contains buttons for each kind of control you can place on a form. It comes with a set of standard items, but you can add more controls to the list.

Working with Events

In the old days of linear programming, if data was changed it had no way of reporting that fact. Other parts of the program had to poll the data, repeatedly checking it to see whether it had changed—a very inefficient technique. Nowadays, with object-oriented programming, objects can report to their owners any condition they deem interesting. Such a report is called an event, and the code that reacts to that event is an event handler.

Working with Objects

In the old days of linear programming. It was necessary to express all program components in terms of letters and numbers. If you were writing a game, and among the components of the game was a schooner and a treasure chest, this schooner would have to be described in terms of letters and numbers, and the treasure chest would have to be designed in terms of letters and numbers.