Visual
Basic is initiated by using the Programs option >
Microsoft
Visual Basic 6.0 > Visual Basic 6.0. Clicking the Visual Basic icon, we can
view a copyright screen enlisting the details of the license holder of the copy
of Visual Basic 6.0. Then it opens in to a new screen as shown in figure 1 below,
with the interface elements Such as MenuBar, ToolBar, The New Project dialog box.
These elements permit the user to buid different types of Visual Basic applications.
The Integrated Development Environment
One of the most significant changes in Visual Basic 6.0 is the Integrated Development
Environment (IDE). IDE is a term commonly used in the programming world to describe
the interface and environment that we use to create our applications. It is called
integrated because we can access virtually all of the development tools
that we need from one screen called an interface. The IDE is also commonly
referred to as the design environment, or the program.
Tha Visual
Basic IDE is made up of a number of components
- Menu Bar
- Tool Bar
- Project Explorer
- Properties window
- Form Layout Window
- Toolbox
- Form Designer
- Object Browser
In previous versions of Visual
Basic, the IDE was designed as a Single Document Interface (SDI). In a Single
Document Interface, each window is a free-floating window that is contained within
a main window and can move anywhere on the screen as long as Visual Basic is the
current application. But, in Visual Basic 6.0, the IDE is in a Multiple Document
Interface (MDI) format. In this format, the windows associated with the project
will stay within a single container known as the parent. Code and form-based windows
will stay within the main container form.
Figure 1 The Visual Basic startup dialog box
Menu Bar
This Menu Bar displays the commands that are required to build an application.
The main menu items have sub menu items that can be chosen when needed. The toolbars
in the menu bar provide quick access to the commonly used commands and a button
in the toolbar is clicked once to carry out the action represented by it.
Toolbox
The Toolbox contains a set of controls that are used to place on a Form at
design time thereby creating the user interface area. Additional controls can
be included in the toolbox by using the Components menu item on the Project menu.
A Toolbox is represented in figure 2 shown below.
Figure 2 Toolbox window with its controls available commonly.
Control |
Description |
| Pointer |
Provides a way to move and resize the controls form |
| PictureBox |
Displays icons/bitmaps and metafiles. It displays
text or acts as a visual container for other controls. |
| TextBox |
Used to display message and enter text. |
| Frame |
Serves as a visual and functional container for controls |
| CommandButton |
Used to carry out the specified action when the user
chooses it. |
| CheckBox |
Displays a True/False or Yes/No option. |
| OptionButton |
OptionButton control which is a part of an option
group allows the user to select only one option even it displays mulitiple choices. |
| ListBox |
Displays a list of items from which a user can select
one. |
| ComboBox |
Contains a TextBox and a ListBox. This allows the
user to select an ietm from the dropdown ListBox, or to type in a selection in
the TextBox. |
| HScrollBar and VScrollBar |
These controls allow the user to select a value within
the specified range of values |
| Timer |
Executes the timer events at specified intervals of
time |
| DriveListBox |
Displays the valid disk drives and allows the user
to select one of them. |
| DirListBox |
Allows the user to select the directories and paths,
which are displayed. |
| FileListBox |
Displays a set of files from which a user can select
the desired one. |
| Shape |
Used to add shape (rectangle, square or circle) to
a Form |
| Line |
Used to draw straight line to the Form |
| Image |
used to display images such as icons, bitmaps and
metafiles. But less capability than the PictureBox |
| Data |
Enables the use to connect to an existing database
and display information from it. |
| OLE |
Used to link or embed an object, display and manipulate
data from other windows based applications. |
| Label |
Displays a text that the user cannot modify or interact
with. |
Project Explorer
Docked on the right side of the screen, just under the tollbar, is the Project
Explorer window. The Project Explorer as shown in in figure servres as a quick
reference to the various elements of a project namely form, classes
and modules. All of the object that make up the application are packed
in a project. A simple project will typically contain one form, which is a window
that is designed as part of a program's interface. It is possible to develop any
number of forms for use in a program, although a program may consist of a single
form. In addition to forms, the Project Explorer window also lists code modules
and classes.
Figure 3 Project Explorer
Properties Window
The Properties Window is docked under the Project Explorer window. The Properties
Window exposes the various characteristics of selected objects. Each and every
form in an application is considered an object. Now, each object in Visual
Basic has characteristics such as color and size. Other characteristics affect
not just the appearance of the object but the way it behaves too. All these characteristics
of an object are called its properties. Thus, a form has properties and any controls
placed on it will have propeties too. All of these properties are displayed in
the Properties Window.
Object Browser
The Object Browser allows us to browse through the various properties, events
and methods that are made available to us. It is accessed by selecting Object
Browser from the View menu or pressing the key F2. The left column of the Object
Browser lists the objects and classes that are available in the projects that
are opened and the controls that have been referenced in them. It is possible
for us to scroll through the list and select the object or class that we wish
to inspect. After an object is picked up from the Classes list, we can see its
members (properties, methods and events) in the right column.
A property is represented by a small icon that has a hand holding a piece of
paper. Methods are denoted by little green blocks, while events are denoted by
yellow lightning bolt icon.
Object naming conversions of controls (prefix)
Form -frm
Label-lbl
TextBox-txt
CommandButton-cmd
CheckBox -chk
OptionButton -opt
ComboBox -cbo
ListBox-lst
Frame-fme
PictureBox -pic
Image-img
Shape-shp
Line -lin
HScrollBar -hsb
VScrollBar -vsb
