Building a Visual Basic Application

·       In the remainder of this chapter, we will provide an overview of a Visual Basic application and how the Visual Basic development environment is used to develop an application.  This should provide you with some idea of what knowledge you need to possess to proceed in this course and introduce the terminology used by the author to describe a Visual Basic application.

Structure of a Visual Basic Application

Project (.VBP)

Module 1 (.BAS)

Form 3 (.FRM)

Form 2 (.FRM)

Control 1

Control 1

Control 2

Control 2

Control 3

Control 3

Application (Project - saved as a file with a .VBP extension) is made up of:

Þ    Forms - Windows that you create for user interface (saved as a file with a .FRM extension).

Þ    Controls - Graphical features drawn on forms to allow user interaction (text boxes, labels, scroll bars, command buttons, etc.)  (Forms and Controls are also called objects.)

Þ    Properties - Every characteristic of a form or control is specified by a property.  Example properties include names, captions, size, color, position, and contents.  Visual Basic applies default properties.  You can change properties at design time or run time.

Þ    Methods - Built-in procedure that can be invoked to impart some action to a particular object.

Þ    Event Procedures - Code related to some object.  This is the code that is executed when a certain event occurs.

Þ    General Procedures - Code not related to objects.  This code must be invoked by the application.

Þ    Modules - Collection of general procedures, variable declarations, and constant definitions used by application (saved as a file with a .BAS extension).