Chapter 1 - Introduction to Application Development

8/3/2019 Chapter 1 - Introduction to Application Development

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Chapter 1

Introduction to

ApplicationDevelopment


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Introduction to VB.NET 2

Content

1.1 Definition of Application.

1.2 Application Development Process.

1.3 Different Types of Application

Development Tools.

1.4 Introduction to Visual Basic.NET.

1.5 The Visual Studio Environment


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1.1 Definition of Application

also called end-userprogramsincludes database programs, word

processors, and spreadsheets. applications software sits on top of

systems software because it is unable

to run without the operating systemand system utilities.


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1.2 Application DevelopmentProcess

Performing a Task on the Computer

Determine Output

Identify Input

Determine process necessary to turngiven Input into desired Output

Program Planning Program Development Cycle


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Problem-solving: approach likealgebra class

How fast is a car traveling if it goes 50miles in 2 hours?

Output: a number giving the speed inmiles per hour

Input: the distance and time the car

has traveled

Process: speed = distance / time


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Pictorial representation of theproblem solving process


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Program Planning

A recipe is a good example of a plan

Ingredients and amounts are determined bywhat you want to bake

Ingredients are input

The way you combine them is the processing

What is baked is the output

Program Planning Tips Always have a plan before trying to write a program The more complicated the problem, the more

complex the plan must be

Planning and testing before coding saves timecoding


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Program development cycle Software refers to a collection of instructions for the computer

The computer only knows how to do what the programmertells it to do

Therefore, the programmer has to know how to solve

problems The Cycle are:

Analyze:Define the problem.

Design:Plan the solution to the problem.

Choose theinterface:Select the objects (text boxes, buttons,

etc.). Code:Translate the algorithm into a programming language.

Testanddebug:Locate and remove any errors in the program.

Complete thedocumentation:Organize all the materials thatdescribe the program.


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Software DevelopmentLifeCycle


Waterfall Model in SDLC (Dix. 2004)

Requirementsspecification

Architecturaldesign

Detaileddesign

Implementationand Unit Testing

Integration andtesting

Operation andmaintenance


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1.3 Different Types of ApplicationDevelopment Tools

Boolean C++

VB 6

ASP - Active Server Pages, a web-scriptinginterface by Microsoft

PHP an open source programming language

Dream Viewer

Lotus Note Oracle

Microsoft Access
http://en.wikipedia.org/wiki/Active_Server_Pageshttp://en.wikipedia.org/wiki/Active_Server_Pages


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1.4 Introduction to VisualBasic.NET

Windows Graphical User Interface

Window = Form

Toolbox of elements called Controls

Text Box

Label

Check Box

Button


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Programming Languages

Procedural

Program specifies exact sequence

Event Driven (VB 6.0 and previous)

Object Oriented Programming (VB.NET)

User controls sequence Click event

Double Click event

Change event


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Visual Studio .NET

Included in Visual Studio .NET

Visual Basic (can also be purchased

separately) Visual C++

C#

J# .NET Framework


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Visual Studio .NET Editions

Standard

Professional

Enterprise Developer Enterprise Architect

Visual Basic.NET

An object oriented language

Object oriented programming terminology


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Object Oriented ProgrammingTerminology

Object ==> Noun

Form and Controls

Property ==> Adjective

Color of a Form

Method ==> Verb

Move a Form

Event ==> Occurs when the user takes action User clicks a button, User moves a form

Class ==> Template to create new object

Each control added is an Instance of a Class


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Dot Notation

Used to reference object'sproperties and events in code

Object dot Property Form.Text, TextBox.Text

Object dot Event

Form.Hide( ), TextBox.Focus( )

To reference an object's events usean underscore instead of a dot

Button_Click, ListBox_TextChanged


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Object Oriented Analogy

Class = automobile

Properties = make, model, color, year

Object = each individual car

Object is also an Instance of theautomobile class

Methods = start, stop, speedup,slowdown

Events = car arrives, car crashes


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Writing Visual Basic Projects

Planning Design Interface

Plan Properties Plan Code

Programming

Create Forms and Controls Set Properties

Write Code


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Open this file directly to work on a Project

VB Application Files

One Solution File .sln Solution User Options File .suo

Form Files .vb

Resource File for the Form .resx

Project Files .vbproj Project User Options File .vbproj.user


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1.5 The Visual StudioEnvironment

Integrated Development Environment(IDE)

Form Designer

Editor for entering code

Compiler

Debugger

Object Browser


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Visual Studio IDE Start Page


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IDE Main Window


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New Project Dialog


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IDE Main Window

Toolbars

Document Window

Form Designer

Solution Explorer Window

Properties Window

Toolbox


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VB Toolbox

Holds thecontrols you

place on aform


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Visual Studio Help

Extensive Help feature

Includes Microsoft Developer Network

library (MSDN)

Entire reference manual

Coding examples


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Modes

Design Time

Run Time

Break Time

Look at the Title Bar

H ll W ld P j t


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messageLabel

pushButton

exitButton

Hello World ProjectDesign the User Interface


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Properties Window-Label1

Rename Label1to messageLabel


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Set the Properties

Label Name messageLabel Text leave blank

Button 1 Name pushButton Text Push Me

Button 2 Name exitButton

Text Exit Form

Name helloForm Text Hello World by your name


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Set the Project's StartupObject

The default startup object is Form1

The name of the form should always

be changed to adhere to naming rules

Click on Project name in SolutionExplorer window, choose Project

menu, Properties and change thestartup object to match the new formname


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Project Property Page Dialog


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Write Code

While the project is running the user canperform actions

Each action by the user causes an Event to

occur

Write code for the events you care about, theevents you want to respond to with code

Code is written as event procedures VB will ignore events for which you do not

write code


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' Display the Hello World message.

Remark Statement

Also known as Comment, used fordocumentation

Non-executable Automatically colored Green in Editor

Begins with an apostrophe ( ' )

On a separate line from executable code At the right end of a line of executable code


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Editor Window

Declarations Section

Class list

Method list


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messageLabel.Text=" Hello World "

Assignment Statement

Assigns a value to a property or variable

Operates from right to left

Enclose text strings in quotation marks (" ")


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Ending a Program

Execute the Close Method of the Form

Methods always have parentheses

(this will help you distinguish them fromProperties which never have parentheses)

Current Form may be referenced as

MeMe.Close( )


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Test and Debug

Save Project - File Menu, Save All

Run Project

Debug Menu, Start

Start (F5)

Start Without Debugging(CTRL F5)

Correct any Errors and Rerun

Compile errors

Run-Time Errors

Logic errors

Syntax errors

"Help is always available from the

Help Menu or by pressing F1."


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Object Class Example

Form dataEntryForm

Button exitButton

TextBox paymentAmountTextBoxLabel totalLabel

Radio Button boldRadioButton

CheckBox printSummaryCheckBox

Horizontal ScrollBar rateHorizontalScrollBar

Vertical ScrollBar temperatureVerticalScrollBar

PictureBox landscapePictureBox

ComboBox bookListComboBox

ListBox ingredientsListBox

Recommended NamingConventions for VB Objects


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Naming Rules andConventions

Have a set of standards and always followthem

No spaces, punctuation marks or reservedwords

Use camel casing

Examples

messageLabel exitButton

dataEntryForm

paymentAmountTextBox


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Chapter 1

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Chapter 1 - Introduction to Application Development