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Event Driven Programming

The following is an example of an event procedure for a CommandButton that counts
and displays the number of clicks made.
Private Sub Command1_Click ( )
Static Counter As Integer
Counter = Counter + 1
Print Counter
End Sub

The first time we click the CommandButton, the Counter starts with its default value of zero.
Visual Basic then adds 1 to it and prints the result.

Make a visual basic program use static Variable.

4.3.12 Module Level Variables

A module level variable is available to all the procedures in the module. They are declared using
the Public or the Private keyword. If you declare a variable using a Private or a Dim statement
in the declaration section of a module—a standard BAS module, a form module, a class module,
and so on—you’re creating a private module-level variable. Such variables are visible only from
within the module they belong to and can’t be accessed from the outside. In general, these
variables are useful for sharing data among procedures in the same module:
In the declarative section of any module
Private LoginTime As Date ‘ A private module-level variable
Dim LoginPassword As String ‘ Another private module-level variable
You can also use the Public attribute for module-level variables, for all module types except BAS
modules. (Public variables in BAS modules are global variables.) In this case, you’re creating a
strange beast: a Public module-level variable that can be accessed by all procedures in the module
to share data and that also can be accessed from outside the module. In this case, however, it’s
more appropriate to describe such a variable as a property:

In the declarative section of Form1 module
Public CustomerName As String ‘ A Public property

You can access a module property as a regular variable from inside the module and as a custom
property from the outside:
From outside Form1 module...

Form1.CustomerName = “Pradip”
The lifetime of a module-level variable coincides with the lifetime of the module itself. Private
variables in standard BAS modules live for the entire life of the application, even if they can be
accessed only while Visual Basic is executing code in that module. Variables in form and class
modules exist only when that module is loaded in memory. In other words, while a form is active
(but not necessarily visible to the user) all its variables take some memory, and this memory
is released only when the form is completely unloaded from memory. The next time the form

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