It's a little known fact, but you can write a VB program from scratch using
nothing more than a simple text editor, such as the Edit or Notepad
applications which come with Windows. In fact, the Visual Basic project
files are exactly that - text files. However, writing a project from scratch
would involve a lot of tedious, detailed manual entries. To simplify
the task, Microsoft has built in to VB a software program to help you write
your VB projects. That software, known as the Integrated Development
Environment (IDE for short) is what comes to the screen when you start
VB and is the topic of this section.
Like any other Windows application, VB consists of multiple windows which
appear at startup. The windows that are displayed when you start VB are
collectively known as the Visual Basic Integrated Development Environment
When you first start VB all of the windows are locked together in what is
called the MDI format. I prefer the SDI format (which you can set in
the options menu) which allows each of the windows to be positioned
independently on your screen. Here's a sample IDE screen which shows
a VB project with one form on which is a single command button.
(click to enlarge)
In particular, VB has the following windows:
- Menu / Toolbar
This is the only element of the IDE which is always visible.
You use it to select which other IDE elements to view and
to add forms or controls to your project. There are many
other features which we will discuss later.
(click to enlarge)
The toolbox is simply a library of controls which you can
place on your application. Once you've placed all the controls
you need onto your applications forms, you can hide the
toolbox to make room for working in the other elements of
- Project Window
This is simply a list of all the forms which make up your
VB project. There are several kinds of forms which we'll
talk about later.
- Property Window
We'll talk about controls later, but such things as push-buttons,
scrolling text boxes, pictures boxes and other features of
most VB applications allow you to enter parameters which
define how these controls work. In VB, these parameters
are called properties. Some properties can be entered at
design time within the IDE, while others must be entered
with code while the program is running.
You add these to your VB application as they are needed.
They are the windows which hold the various controls (buttons,
text boxes, etc.) which make up your application.
- Code Window
Like it's name implies, this is where you type in the code
that VB executes. Notice that the heading of the window indicates
with which event the code is associated.
A VB Session
When VB begins a new project, it starts with a single form which
has no controls placed on it. A session in VB would go something
- Add additional forms (if needed)
- Set form properties
- Place controls on forms
- Set control properties
- Write code for form/control event procedures
- Create executable (.EXE) or simply RUN program within the IDE
- Save project
It's important to understand that each form in VB is saved as a standalone
file on your computer. The listing of all forms, and their location on your
hard disk, are kept in another file which is called the project file. In
VB3 the project file extension was .MAK but in VB6 it is .VBP. This file
is just an ASCII text file which provides information about the VB project.
There is a variety of other information which is held within the file,
but all of it is directed towards describing those files (and controls)
which make up the
VB project. We'll talk more about the content of the file in other sections
of this tutorial. As your skills improve, you'll even feel comforable about
editing the project directly, using a simple text editor such as notepad.
I do it occasionally when I want to make a simple change to a program without
going through the VB IDE.
Even more useful is that if I want to capture a routine that I know is in
a VB project, I can call up the file that has the code and copy it to the
clipboard for insertion into my new project. This has the benefit of being
very quick and it lets me use search tools that are not a part of the VB IDE.
Your First Application
Ok, it's already time to create you first application. Beginner's are usually
shown what's called a "Hello World" application. It's called this because all
the application does is display the words "Hello World" when the user presses
a button. As useful applications go, it's not much, but it does show what is
involved in creating an application.
- Step 1.
Start VB. As it VB comes up, it automatically creates a NEW application
consisting of only 1 form which has no controls.
- Step 2.
Using the mouse, move the cursor over the toolbox and click with the left
mouse on a command button control. This selects the button. Now move
the cursor to the form and while pressing the left mouse button draw out
a rectangular shape with the mouse. Once the shape is drawn and the left
mouse is released, a command button appears on the form.
- Step 3.
Change the CAPTION property of the command button. Do this by clicking once
on the button to select it, then pressing F4 to bring up the Property
window. Scroll in the window until you find the CAPTION property. Highlight
the CAPTION property and type in "PRINT". The text on the command button will
be replaced by what you type.
- Step 4.
Remember earlier in the tutorial that we talked about writing code for
events? Well, each of VB controls recognize certain events. In this
example, the CLICK (left mouse press and release) is the event which
corresponds to pressing the button.
VB uses a nomenclature such as command1_click() for event procedures.
Since we've not yet discussed procedures this information is a bit
premature. For now, just take on faith that VB provide a place to write
the code which will be executed when the button is clicked.
To get to the location where the code will be placed, DOUBLE-CLICK on the
button. A new windows, the CODE WINDOW, will appear with the cursor
in place, ready for you to type the code. Type the following line of code:
PRINT "Hello World"
- Step 5.
Your program is now complete and ready to run. Within the IDE you simply
press F5 to run the program. Do so now.
Your application will appear as a single window in which there is a single
button labeled "Print". Press the button with your mouse and you will see
the words "Hello World" appear in the upper left corner of the window.
That's it! You've just written your first VB application.
To return to the IDE, click on the "X" button at the top right of the form.
Later we'll discuss better ways to exit from a program.