2. I N D E X
3) RAPID APPLICATION DEVELOPMENT
4) Editions of Visual Basic
5) Versions of Visual Basic
6) Advantages Of Visual Basic
7) Disadvantages Of Visual Basic
8) Starting Visual Basic
9) Hardware Requirement
10) Visual Basic Concepts
11) Visual Basic Integrated Development Environment(VBIDE):-
12) Code Editor Window
13) WORKING WITH WINDOWS
3. Defining Visual Basic
Visual Basic is a tool that allows you to develop Graphical User Interface
applicàtion.
Visual Basic can create windows programs whèreas BASIC can only
create DOS based programs.
Visual Basic provides massive support for easily creating the user
interface to your application in which you use a mouse to type your code that is
to be executed.
Visual Basic is an event driven programming model. In old BASIC you
have to write code to watch for the occurence of user events(pressing the key,
using a mouse etc).
Visual Basic provides built in support to internet access.
4. Visual Basic is one very powerful programming system that helps one
to develop sophisticated, graphical applications that can be run on Microsoft Windows
Environment. Visual Basic is actually BASIC language, which is visual in its nature. Visual
programming style involves a lot of illustrations rather than writing numerous lines of codes
to describe the appearance, functioning etc. of the application's interface.
The BASIC language (acronym for Beginner's All Purpose Symbolic Instruction
Code) was developed by John Kemery in 1960's. BASIC language was hugely popular,for it
was simple yet powerful language. The same old BASIC language has now evolved into
Visual Basic. Visual Basic was developed in early 1999's by Microsoft Corporation. Visual
Basic is also being referred as VB.
Introduction TOVISUAL BASIC
5.
6. Visual Basic programming environment provides all features that are
required to develop a graphical user interface as already to use components. In
developing such an interface, the programmer employs user-friendly components
such as windows, menus, buttons, list boxes etc.. Visual Basic6.0 provides many more
powerful features. Some prominent ones are-
It is a successor of BASIC language.
Visual Basic supports event driven programming.
It is an event driven programming language.
It is having RAD tools.
Visual Basic offers many tools that provide a quick and easy way to develop
applications.
Visual Basic also provides many wizards that can automate tasks or even
automate coding.
( A Wizard is generally an automated way of doing things. The
wizard guides you at every step, what to do, how to do etc.)
It has useful debugger and error handling facilities.
It has array of mathematical string handling and graphical facilities.
7. Thus, Visual Basic is a high level programming language which provides following
features to users:
Object Oriented
Event Driven
Autocompletion Wizard
Error Trapping Tools
Flexible Environment
Crystal and Data Report
Help Files
Clipboards and Printers
Database Connectivity
Wizard Facility
8. RAPID APPLICATION DEVELOPMENT
Rapid Development of application is possible through RAD(Rapid Application
Development) tools. The RAD tools are the tools that enable one to create applications
in shorter time as compared to conventional languages. A range of applications can be
created with RAD tools.
RAD describes a method of developing software through
the use of pre-determined tools or wizards. While developing large applications, the RAD
tools are used to create prototypes of the large application. A prototype is the first
model that is made of something. The prototype is used as a basis for later improved
model.
9. Editions of Visual Basic
Visual Basic is available in three versions, each geared to meet a specific set of development
requirements.
(i) The Visual Basic learning Edition allows programmers to easily create powerful
applications for MS Windows and Windows NT. It includes all intrinsic controls, flex grid, tab
and data bound controls. It is also known as Standard Edition and is generally used for
learning purposes.
(ii) The Professional Edition provides computer professionals with a set of tools for
developing solution for others. It includes all the features of the Learning Edition, plus
additional Active-X controls, the Internet Information Server Application Designer, integrated
Visual Database tools and Data Environment, Active Data Objects, and the Dynamic HTML
page designer. Most professional programmers use Professional Edition.
(iii) The Enterprise Edition allows professionals to create robust distributed applications in a
team setting. It includes all the features of the Professional Edition, plus Back Office tools
such as SQL server, Microsoft Transaction Server, Internet Information Server, Visual Source
Safe, SNA server and more. Enterprise Edition users are generally those who are working in a
networked, distributed environment.
10. Versions of Visual Basic
The Original Visual Basic for DOS and Visual Basic for windows were introduced in
1991.
The next version Visual Basic3.0 was released in 1993. It was vast improvement
over previous version.
The next version Visual Basic4.0 was released in the year 1995(added 32bit
publication support).
Visual Basic 5.0 was released in the late 1996. New Environment supported
creation of Active X controls, deleted 16 bit application support.
Visual Basic6.0 was released with the following features:-
Faster compiler.
New Active X Data control Object.
Allows Database Integration with wide variety of applications.
New Data Report Designer.
New package and Deployment Wizard.
Additional Internet capabilities.
11. Advantages Of Visual Basic
1) It has a simple language.
2) It has comprehensive on-line help facilities.
3) It supports GUI features.
4) It supports the facilities of integration of COM components written in other
languages.
5) It has Object Linking and Embedding(OLE) facilities.
12. Disadvantages Of Visual Basic
1) Programs written in Visual Basic is slower and less robust.
2) Visual Basic programs has limited portability in Windows Environment.
3) It has very limited access to library.
4) OLE(Object Linking and Embedding) needs large amount of memory.
13. Starting Visual Basic
To startup Visual Basic:-
1) Click at the Start Button.
2) Select All programs -----> Microsoft Visual Basic.
or
If Visual Basic is installed as a part of Microsoft Visual Studio Suite then,
All Progams -------> Microsoft Visual Studio ------> Microsoft Visual Basic6.0
And Visual Basic's startup dialog box appears on the screen.
14. Hardware Requirement
The followings are the hardware requirements for Visual Basic:-
1) Pentium 90MHz or higher microprocessor.
2) Video Graphic Adaptor(VGA) monitor (640*480 resolution or higher).
3) 24MB RAM, Windows 95/98 or higher version.
32MB RAM, or higher for Windows NT.
4) Color monitor.
5) Compatible mouse.
15. Visual Basic Concepts
Visual Basic is a Windows Development Language, which also supports Event
Driven Programming. Also, coding is done interactively in Visual Basic.
Working of Windows, Events, and Messages
A window can be thought of as a rectangular region with its own boundaries.
There are actually many other types of windows. A command button is also a window.
Icons, text boxes, option buttons and menu bars are all windows.
The Windows Operating System manages many of these windows by assigning
each one a unique id number(called Window Handle). Events can occur through user
actions such as a mouse click, a key press etc. through programmatic control, or even as a
result of another window's actions.
An Event refers to the occurence of an activity.Each time an event occurs, it
causes a message to be sent to the operating system. The system processes the message
and broadcasts it to the other windows. Each window can then take the appropriate action
based on its own instructions for dealing with that particular message.
16. A message is the information/request sent to the application.
Dealing with all of the possible combinations of windows, events and messages
could be mind-boggling. Fortunately, Visual Basic insulates you to deal with all of the low-level
message handling. Many of the messages are handled automatically by Visual Basic. This
allows to quickly create powerful applications without having to deal with unnecessary
details.
The Event Driven Model:
In an Event Driven application, the code doesn't follow a predetermined path rather
it executes different code sections in response to events. Events can be triggered by the user's
actions, by messages from the system or other applications, or even from the application
itself. The sequence of these events determines the sequence in which the code executes,
thus the path through the application's code or the sequence of execution differs each time
the program runs.
Interactive Development:
The traditional application development process can be broken into three distinct
process or steps:
Writing, Compiling and Testing
code.
17. Unlike the traditional languages, Visual Basic uses an interactive approach to development
that merges these three steps:
With most languages, if any mistake is there in writing the code, the error is caught
by the compiler when the application is compiled. The error is then found and fixed. The
compile cycle is again begun, repeating the process for each error found. Visual Basic
interprets the code when entered, catches and highlights most syntax or spelling errors there
and then. It's almost like having an expert watching over your shoulder as code is entered.
In addition to catch the errors on the fly, Visual Basic also partially compiles the
code as it is entered. If the compiler finds an error, it is highlighted in the code. You can fix the
error and continue compiling without having to start over.
Because of the interactive nature of Visual Basic, the application can be run
frequently as one develops it. This way the test of the effects of code can be done while
working rather than waiting to compile later.
18. Visual Basic Integrated Development Environment(VBIDE):-
When you start a new project, Visual Basic shows the screen. This is Visual Basic Integrated
Development Environment( VBIDE).
The Visual Basic IDE consists of the following elements:-
Title Bar
Menu Bar
Tool Bars
Tool Box
Form Designer
Project Explorer Window
Properties Window
Form Layout Window
TITLE BAR
The Title Bar displays the title of the project. Bydefault, Visual
Basic will give names as Project1, Project2 -----etc, to the project. The title bar also displays
the word (design). This means the application is currently in design mode.
A Visual Basic application works in three modes:
Design Mode
Run Mode
Break Mode
19. While application is being created or designed, it is in Design Mode. When the application is
executing, it is said to be in Run Mode. And while an application is in a state of suspension,
it is said to be in Break Mode.
MENU BAR AND PULL DOWN MENU
A Menu Bar is displayed directly below the title bar and includes a lot of
options. Each option on the Menu Bar has a drop down list of items (known as Pull-down
Menus) that help to perform various tasks.
TOOL BARS
A Tool Bar is a bar that displays icons for commonly used tasks. The
Standard Toolbar of Visual Basic displays icons for the most frequently used commands in
Visual Basic. The Standard Toolbar can also contain buttons from toolbar or properties
window.
TOOL BOX
Forms are the main part of the project .Forms are used to display
various various controls that form the user interface. Forms are used to display things like
labels, graphics, controls etc
Controls are objects such as text boxes, buttons, labels, list
boxes etc, that are
20. drawn on form to get data input or to display output.
A Toolbox is a window that displays a set of tools that may be used
to place controls on a form. The buttons on the toolbox depict controls.
FORM DESIGNER
The Form Designer window is the Form window in design form. In Form
Designer Window, different controls are placed on the form. A grid of dots are seen on the form
designer window. The purpose of grid is to help in lining up controls at the time of design. These
dots disappear at the time of form execution.
PROJECT EXPLORER WINDOW
This window shows the list of forms and modules in a project. A project is a
collection of files used to build an application. All these files are listed in Project Window.
PROPERTIES WINDOW
A form may consist of many objects ie, controls on it. Every control has some
properties associated with it. A property is a characteristic of an object such as its size, its
caption or its colour etc. The Properties Window lists the properties of a selected control or for
the form.
If the Properties Window is not displayed then it can be
viewed through View ----> Properties Window command or by pressing F4 key.
FORM LAYOUT WINDOW
The Form Layout Window shows how big a form is in relation to the screeen.
It also displays the position of the force where it'll be displayed when the project is run.
21. Code Editor Window
The Code Editor Window is where the Visual Basic code for an application is
written. By code we mean language statements, constants and declarations. A
separate Code Editor Window is created for each form or control that you create in
your application. Using the Code Editor Window, any of the codes of the
application can be quickly viewed and edited.
To Open The Code Window
Double click the form or control for which you choose to
write code. Or from the Project Explorer Window, select the name of a form or
module, and choose the View Code Button from the Project Explorer's toolbar or
press F7 key.
22. WORKING WITH WINDOWS
Opening Windows
There are different types of windows in Visual Basic interface such as
Project Explorer Window, Properties Window, Form Layout Window, Toolbox etc.
Sometimes, when you start Visual Basic you don't see any one
or all of these windows in the initial screen.
To open the desired window, just click upon the View option on the Menu
Bar and select the name of the desired window to be opened.
Windows can be closed by clicking at their close(X) button.
23. Resizing And Moving Windows
To resize a window, take the mouse pointer to any of the boundaries of the
window. Your cursor will change into double ended arrow. Now drag the window in desired
direction to enlarge or reduce its size.
To resize Form Designer, you have to place the mouse pointer on
the size handles(rectangular dots on the boundary) and then drag it to new location.
24. DOCKING WINDOWS
Docking means connecting. Many of the windows in IDE can be docked or connected to each
other or to the edge of the screen. These include Toolbox, Form Layout Window, Project
Explorer, Properties Window etc.
A window that can be resized or moved and connected
to other windows is known as Dockable Window. Most of the Visual Basic's windows are
dockable.
To Dock Or Undock A Window
To dock or undock a window the following procedures should be followed:-
If you look at the initial screen of Visual Basic, you generally find some docked windows.
To undock a docked window, just drag its title bar to a new location.
The moment you release mouse button, the window will be undocked.
To dock undocked windows, you need to follow the reverse process ie, drag the title bar of the
undocked window to the boundary of other window with which it is to be docked and release
the mouse button. The two windows will get docked.
Windows can be docked with the main Visual Basic Window also, by following the same
procedure above.
25. Quitting Window(Visual Basic)
To quit Visual Basic, you need to select File ----> Exit
command or press Alt+Q. You can also quit from Visual Basic the way you exit from most of
the window applications ie, by pressing Alt+F4 or by clicking the close(X) button or by double
clicking its control menu icon that appears on the upper left corner of the window.
Thus it can be concluded that to
quit from Visual Basic you can press:-
1) File ----> Exit command.
2) Alt+Q
3) Alt+F4 or
4) Close(X) Button
