CIS 365: Visual Application Development

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CIS 365 Visual Application Development

• Introduction to Computers and Programming

2
Objectives

• Computer Operations
• Programming Languages
• VB.Net Language
• Programming Process
• Modular Structure
• Procedural Code
• Algorithms

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Computer Operations (inputs/processes/outputs)
4
Programming Languages

• 1st Generation (Machine Languages)
• Represented instructions as sequence of binary
  numbers
• 2nd Generation (Assembly Languages)
• Replaced numbers with abbreviated words
• Required translator programs (assemblers) to
  convert assembly into machine language
• Low Level
• Machine-dependent, only run on certain computers
• Use instructions tied to specific hardware
• Many instructions required for a single operation

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Programming Languages

• 3rd Generation
• Procedure-oriented, 1 instructionmany
  operations, focus on problem instead of hardware
• Object-oriented, use objects with properties,
  behaviors, reuse of objects is the goal
• 4th Generation
• 4GL allow users to access/format without writing
  code
• Visual-oriented permit programmer to manipulate
  graphical objects directly with code to support
  objects
• High Level
• Written using instructions resemble English
  language
• Can be translated to run on a variety of computer
  types

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Programming Languages

• Procedural
• Decisions about actions and order of actions are
  controlled by the programmer, not user
• Event-Driven
• User controls sequence of events by action taken
• User chooses between options by selecting an
  object which triggers an event that runs a
  specific procedure
• Still requires procedures to be coded

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VB .NET Language

• It allows event-driven programming
• It is object-oriented
• Everything revolves around objects
• Each object has properties and methods
• Properties are characteristics
• Methods are actions the object can take
• Some objects can raise events, i.e. notify other
  objects that something happened

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The Programming Process

• Understand the problem (Analysis)
• The description of what the user needs
  inputs/processes/outputs
• A good programmer is often part counselor, part
  detective
• Plan the logic (Design)
• Programmer plans the steps to the program,
  deciding what steps to include and how to order
  them.
• Common tools are flowcharts, pseudocode, and IPO
  (Input/Processing/Output) Table
• Code the program (Coding)
• Translate design of logic into desired language
  syntax
• Test the program (Testing)
• Unit Test, Integrated Test, System Test
• Put the program into production (Implementation)
• Load it on user(s) computers and train them

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Modular Structure

• Modular Programs
• programs whose structure consists of interrelated
  forms and tasks, arranged in a logical and easily
  undertandable order to form an integrated unit
• Easy to develop, correct, and modify
• Each module is designed/developed to perform a
  clearly defined and specific function
• Visual Basic
• Form Modules (code and objects on form)
• General Procedures procedural code that performs
  processing tasks
• Sub Procedures
• Function Procedures

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Procedural Code

• Sequence
• ordered list of operations
• Selection
• control the flow of operation
• Iteration
• repeat operations until a certain exit condition
  is met

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Algorithms

• Before programming, must understand
• Data to be used
• Desired result
• Steps required to produce result
• Algorithm is a list of steps,
• step-by-step sequence of instructions
• How data is to be processed to produce the
  desired output
• Not bound to a programming language, the
  English version of the program
• The algorithm is more important than the language

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Summary

• Computer Operations
• Input
• Processing
• Output

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Summary

• Programming languages come in a variety of forms
  and types
• Machine languages
• Assembly languages
• Procedural languages
• Object oriented languages
• 4GL
• Visual languages

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Summary

• VB.Net is
• Event-driven
• Object-oriented
• Graphical

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Summary

• Software Development Process
• Analysis
• Design
• Algorithms
• Flow Charts, PseudoCode, IPO Tables
• Coding
• Modular
• Procedural
• Sequence/Selection/Iteration
• Testing
• Implementation