Lecture Learning programming using Visual Basic Net – Chapter 2 Creating simple Visual Basic NET windows applications

Learning objectives of this chapter include The Integrated development environment (IDE) is used for modern software development; the IDE contains tools to write code, build a GUI , and test and debug applications; overview of the application construction process; design issues are addressed;...

CHAPTER TWO

Creating Simple Visual Basic NET Windows Applications

Chapter Introduction

• The Integrated Development Environment (IDE)

is used for modern software development.

• The IDE contains tools to write code, build a

GUI , and test and debug applications.

• Overview of the application construction

process.

• Design issues are addressed.

• Visual Basic NET controls are examined.

• The MsgBox statement and InputBox() function

are visited.

• Design and construct simple complete

applications from scratch

• Explain the structure of Visual Basic NET

• List the characteristics of several Visual

Basic NET controls

• Identify the purpose of each major control

of the Visual Basic NET IDE

• Overview of the Construction Process

– Visual Basic NET runs under Windows.

– The programmer creates the application.

– The project is an application under

construction.

– The application is saved to disk periodically.

– An executable file is generated from the

finished application program.

Visual Basic NET’s Three Modes

• Design Mode

– Placing, arranging, and customizing the

appearance of buttons, labels, and other

controls on a form.

– Writing processing scripts (source code).

– Saving the solution.

– Making an executable file.

• Run Mode

– Executes the solution.

– Used to evaluate the workability of a part of

the project.

– Used to show the user how the solution will

work.

Visual Basic NET’s Three Modes

(cont.)

• Break Mode

– Helps the developer with debugging.

– Enables the developer to switch back to run

mode or design mode.

Design Time and Run Time

• In design mode, the project is in design

time

• In run mode, the project is in run time

• Some errors can be found and corrected

in design time

• Other errors can only be detected during

run time

2.2 Overview of Controls

• Standard controls are used to create friendly applications

user-• Standard controls help users lower the

learning curve for new programs

Categories of Controls

• Trigger: Initiate processing

– Ex Button, MainMenu, and Timer

• Input: Get data from user

– Ex TextBox, RadioButton, and CheckBox

• Output: Display results to user

– Ex Label, DataGrid, and ListView

Categories of Controls (cont.)

• Organize: Group other controls

– Ex Form, GroupBox, and Panel

• Data Access: Interface with databases

– Ex Entire Data Group and DataGrid

The Correct Control for the Job

• Chose controls to satisfy user

2.3 The Visual Basic NET Development Environment

• The IDE helps develops create efficient

and effective solutions

• The IDE for Visual Basic NET is common

to all the other tools available in the Visual Studio NET suite

Getting Started

• Open an existing project or begin a new

project from the Start Page

• Use the My Profile option to set up the

IDE

Visual Basic NET Solution

Structure

• Every application will be organized as a

“solution.”

• Solution Explorer is an interface for

viewing and managing containers and

associated items

• Items are files that make up your project,

such as forms, source files, and classes

• Avoid the temptation to use the Save

As…, save option

• Use the Save and Save All Toolbar icons

• Many of the features of the Visual

Basic NET IDE have been introduced

• Next, some of the controls to write simple

programs will be introduced

• Experimentation is encouraged

• Hands-on experience is important

2.4 Introducing the Windows Form

2.5 The Button Control

• React to the click of the use

• Perform a task associated with the name

of the button that is displayed on its face

Appearance and Use

• Appears as a rectangular-shaped control

on a form

• Its face can display text, an image, or

both

• The face of the button should clearly

indicate its function

Common Properties of the Button

• Components are able to respond to

events

• The click event is generated when the

user clicks the mouse button

• You write code to handle events

• Double-click the Button control to

automatically open the code window

2.6 The Label Control

• Used to display information to the user

• Used to label other controls or show

results of a calculation

– Ex Check box and radio button labels.

Appearance and Use

• Appears as a rectangular area that can be filled with text

• You have some control over size and

alignment of text

• You can include a border around the label

• Many of the Button control properties

apply to the Label control

• The Text Property is the most-used

property for the Label control

• Example 2.1 Using the Label Control

– Demonstrates two main uses of the Label

control

• To display a message to the user.

• To display “labeling” information for the user.

2.7 The TextBox Control

• Provides an area for the user to type while the program runs

Appearance and Use

• Displays as a rectangular area that

provides the user a place to type

• You can limit the user types

• You can also surround the TextBox with a border

• Some of the TextBox control properties

are only available at run time

• The value of the Text property is used

most frequently

• Control of user entry is shared between

properties and events

• The PasswordChar property allows you to

Properties (cont.)

• TextLength property determines the

number of characters contained in a

textbox

• Selection… properties provide information

on user selections in the TextBox control

Focus means the user is currently working

with the specific control

• Enter - Occurs when input focus is

Common Events for the TextBox

InputBox Function

• Two alternate ways to receive information from the user and to display information on the screen

MsgBox Statement

• The MsgBox statement will display

information that requires user intervention

– MsgBox(“A prompt”, Buttons,”A title”)

InputBox() Function

• The InputBox() function requests

information from the user with a dialog

box It requires user intervention

– InputBox(“A prompt”,”A title”,”A default

response”)

Chapter Summary

• An application being developed in Visual

Basic NET is called a project.

• Visual Basic NET uses three modes of

operation.

• The Visual Basic NET IDE contains a

number of development tools.

• During the design phase, descriptive names

should be applied to important controls.

Chapter Summary (cont.)

• The Windows Form control is used to contain the other GUI controls.

• The Button control enables the user to trigger

a process by a click event.

• The MsgBox statement provides an alternate means to provide information to the user.

• The InputBox() function provides an alternate way to receive information from the user.