objectives machine language vs.. high-level language procedure-oriented, object-oriented, and event-...
TRANSCRIPT
Objectives
• Machine language vs.. High-level language• Procedure-oriented, object-oriented, and event-
driven languages• Background of Visual Basic• VB Integrated Development Environment• Online documentation and Help features
Software
• Application Software – Word Processors– Database s/w– Spreadsheets– Painting programs– Web browsers, email
programs
• System Software– Operating Systems
• Windows• Macintosh OS• Unix• Linux
– Drivers
Software is comprised of instructions that get a computer to perform a task.
Software
Computer
Hardware
Processing Unit
Output Unit
Input Unit
Memory Unit
System Software
Application Software
Operating System
Language Processor
Utility Software
General Software
CustomizedSoftware
Copyright 1999 Prentice-Hall, Inc. 4Exploring MS Visual Basic 6
Application Programs
Program - detailed set of instructions for a computer to execute
Application programs (applications or apps) - self-contained collection of programs that perform a task for the end user
Programming language - formal language used to give instructions to computers
Programming Languages
• Programming languages allow programmers to code software.
• The three major families of languages are:– Machine languages– Assembly languages– High-Level languages
Software
Collection of Programs
Set of Commands
( Pre Defined )
Programming Language
Programmer
Copyright 1999 Prentice-Hall, Inc. 7Exploring MS Visual Basic 6
History of Programming Languages
• Machine language• Procedure-oriented languages• Object-oriented languages• Event-driven languages• Natural languages
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History of Programming Languages
• Machine Language – different for each computer processor
• Procedure-Oriented Languages– FORTRAN– COBOL– Pascal– C– Ada
Copyright 1999 Prentice-Hall, Inc. 9Exploring MS Visual Basic 6
History of Programming Languages
• Object-oriented languages– Smalltalk– C++– Ada 95
• Event-driven languages– Visual Basic– most Visual languages
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History of Programming Languages
• Natural languages– computer will accept a user’s native or natural
language, such as English– Researchers continue to work in this area
VISUAL BASIC
Why VB? Rationale…
• Easy for beginners to produce a working program
• Capable of high end programs• Graphical• OOP (for the most part)• Affordable• Many free resources available
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Copyright 1999 Prentice-Hall, Inc. 13Exploring MS Visual Basic 6
Background of Visual Basic
• BASIC– Beginner’s All-purpose Symbolic Instruction Code– By John Kemeny and Thomas Kurtz – Designed to teach programming to beginners– BASIC language interpreter, one of Microsoft’s first
products
Copyright 1999 Prentice-Hall, Inc. 14Exploring MS Visual Basic 6
Background of Visual Basic
• BASIC – Beginners' All purpose Symbolic Instruction Code– Included with DOS– QBASIC - included with DOS Version 5 - subset of BASIC
• Visual Basic– 1992 - Visual Basic 1 for Windows 3– Visual Basic 4 - for Windows 95– Visual Basic 5 - for Office 97– Visual Basic 6 - for Windows 98 & Office 2000
VISUAL BASIC
• GUI– (Graphical user interface )
• IDE – (Integrated development environment)
• EDP– (Event Driven Programming)
• The GUI environment is event-driven• An event is an action that takes place within a
program– Clicking a button (a Click event)– Keying in a TextBox (a TextChanged event)
• Visual Basic controls are capable of detecting many, many events
• A program can respond to an event if the programmer writes an event procedure
Slide 1- 16
Event Driven Programming: Events
Starting VB 6.0
• Go to Start • All Programs• Microsoft Visual Studio 6.0• Microsoft Visual Basic 6.0
Select
Copyright 1999 Prentice-Hall, Inc. 18Exploring MS Visual Basic 6
Toolbox
Form Designer Window
Code Editor Window
Project Explorer
Properties window
Form Layout Window
Visual Basic 6 Interactive Development Environment
Elements of the Integrated Development Environment
• Application icon• Application name• Context menus• Controls• Current project• Design view mode• Title bar
• Major windows– Form Designer– Form Layout– Toolbox– Project Explorer– Object Browser– Properties– Code Editor– Immediate, Locals, Watch