Microsoft Visual Basic 2010:
Reloaded
Fourth Edition
Chapter One
An Introduction to Visual Basic 2010
Objectives
After studying this chapter, you should be able to:
• Create a Visual Basic 2010 Windows-based
application
• Manage the windows in the Integrated Development
Environment (IDE)
• Set the properties of an object
• Add a control to a form
• Use the Label, Button, and PictureBox tools
• Use the options on the Format menu
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Objectives (cont'd.)
•
•
•
•
•
•
•
•
Enter code in the Code Editor window
Save a solution
Start and end an application
Print an application’s code and interface
Write an assignment statement
Print an application’s code and interface
Close and open an existing solution
Find and correct a syntax error
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Visual Studio 2010
• Visual Basic 2010 is an object-oriented
programming language
– Object: anything that can be seen, touched, or used
– Class: a pattern used to create an object
– Instance: an object created from a class; object is
said to be instantiated
• Integrated Development Environment (IDE):
– Contains all the tools and features needed to create,
run, and test programs
– Includes Visual Basic, Visual C++, Visual C#, and
Visual F#
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Visual Studio 2010 (cont'd.)
• Application: program or suite of programs
• Windows-based application:
– Has a Windows user interface
– Runs on a personal computer
• User interface: what the user sees and interacts with
when using an application
• Web-based application:
– Has a Web user interface
– Runs on a server
– Accessed with a computer browser
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Creating a Visual Basic 2010
Windows Application
• Windows applications consist of solutions, projects,
and files
• Solution: a container that stores projects and files
for an entire application
• Project: a container that stores files associated with
a specific portion of the solution
• A solution may contain one or more projects
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Solutions, Projects, and Files (cont'd.)
Figure 1-1: Illustration of a solution, project, and file
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Starting Microsoft Visual Studio 2010
Figure 1-2: How to start Visual Studio 2010 or Visual Basic 2010
Express Edition
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Figure 1-3: Visual Studio 2010 Professional startup screen
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Figure 1-4: Visual Basic 2010 Express startup screen
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How to Create a Visual Basic 2010
Windows Application
Figure 1-5: How to create a Visual Basic 2010 Windows application
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How to Create a Visual Basic 2010
Windows Application (cont’d.)
Figure 1-5: How to create a Visual Basic 2010 Windows application (cont’d.)
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How to Create a Visual Basic 2010
Windows Application (cont’d.)
Figure 1-6: Options dialog box
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How to Create a Visual Basic 2010
Windows Application (cont’d.)
Figure 1-7: Completed New Project dialog box in Visual Studio 2010
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How to Create a Visual Basic 2010
Windows Application (cont’d.)
Figure 1-8: Completed New Project dialog box in
Visual Basic 2010 Express Edition
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How to Create a Visual Basic 2010
Windows Application (cont’d.)
Figure 1-9: Solution and Visual Basic Project
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Managing the Windows in the IDE
Figure 1-10: How to manage the windows in the IDE
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The Windows Form Designer Window
• Windows Form Designer window:
– Allows you to create (design) the GUI
• Graphical user interface (GUI):
– What the user sees and interacts with
• Windows Form object (or form):
– Foundation for the user interface
– Add other objects such as buttons/text boxes to form
– Title bar with caption and Minimize, Maximize, and
Close buttons
– Tab at top of designer window has Form1.vb [Design]
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The Windows Form Designer Window
(cont’d.)
Figure 1-11: Windows Form Designer window
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The Solution Explorer Window
• Solution Explorer window:
– Displays a list of projects contained in this solution
– Displays the items contained in each project
Figure 1-12: Solution Explorer window
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The Solution Explorer Window
(cont'd.)
• Source file: a file containing program instructions
• Code: program instructions
• Form file: a file containing code associated with a
Windows form
• Give each form file a meaningful name using the
Properties window
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The Properties Window
• Properties: a set of attributes that determine an
object’s appearance and behavior
• Properties window: displays properties of selected
object
• Default property values are assigned when an
object is created
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The Properties Window (cont'd.)
Figure 1-13: Properties window showing the Form1.vb file’s properties
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The Properties Window (cont'd.)
• Properties window includes an Object box and a
Properties list
• Object box:
– Located immediately below Properties window title bar
– Contains the name of the selected object
• Properties list:
– Left column displays names of properties
• Use the Alphabetical or Categorized buttons to sort the
display of properties
– Settings box: Right column containing the current
value of each property
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Properties of a Windows Form
Figure 1-14: Properties window showing a partial listing of the form’s properties
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Properties of a Windows Form
(cont'd.)
• Class definition: block of code that defines the
attributes and behaviors of an object
– All class definitions are contained in namespaces
• Namespace: defines a group of related classes
• Dot member access operator: the period that
separates words in an object’s name to indicate a
hierarchy of namespaces
• Name property: used to refer to an object in code
– Give each object a meaningful name
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Properties of a Windows Form
(cont'd.)
• Pascal case:
– First letter of each word in the name is uppercase
– First part of name is object’s purpose
– Second part of name is object’s class
• Text property: controls the caption displayed on
form’s title bar
• StartPosition property: determines the form’s
position on the screen when application starts
• Font: general shape of characters in text
– Recommended font is Seqoe UI font
• Point: a measure of font sizes; one point = 1/72 inch
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The Toolbox Window
• Toolbox:
– Contains objects that can be added to other objects,
such as a form
– Each tool has an icon and a name to identify it
– Each tool represents a class from which objects, called
controls, can be created
• Controls:
– Objects displayed on a form
– Represented as icons in the toolbox
• Controls on a form can be selected, sized, moved,
deleted, locked in place on the form and unlocked
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Figure 1-15: Toolbox window
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The Toolbox Window (cont'd.)
Figure 1-16: How to add a control to a form
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The Toolbox Window (cont'd.)
Figure 1-17: How to manipulate the controls on a form
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The Label Control
• Label control:
– Displays text that user cannot edit
– Used as “prompts” to explain controls or display output
– Name should end with “Label”
• Control names use camel case
• Camel case: lowercase first word; uppercase first
letter of each subsequent word in the name
• Not necessary to assign meaningful names for labels
used as prompts because they are never used in
code
• Labels used for output should have meaningful
names
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The Label Control (cont'd.)
Figure 1-18: Wizard application’s user interface
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The Button Control
• Button control:
– Performs an immediate action when clicked
– Its name should end with “Button”
• Text property: specifies the text that appears on the
button’s face
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The Picture Box Control
• Picture box control: used to display an image on a
form
• Image property: specifies the image to display
• SizeMode property: handles how the image will be
displayed
– Settings: Normal, StretchImage, AutoSize,
CenterImage, or Zoom
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Using the Format Menu
• Format menu: provides options for manipulating
controls on the form
– Align option: aligns two or more controls by left,
right, top, or bottom borders
– Make Same Size option: makes width and/or height
of two or more controls the same
– Center in Form option: centers controls horizontally
or vertically on the form
• Multi-select controls by clicking the first, then using
Ctrl-click for each additional control
– First control selected is the reference control
• Its size/position is used to adjust the others
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The Code Editor Window
• Events: user actions while program is running
– Examples: clicking, double-clicking, scrolling
• Event procedure: set of instructions to be
processed when an event occurs
– Tells the object how to respond to an event
• Code editor window: used to enter event
procedure’s code
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The Code Editor Window (cont'd.)
Figure 1-19: How to open the Code Editor window
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The Code Editor Window (cont'd.)
Figure 1-20: Code Editor window
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The Code Editor Window (cont'd.)
• Class statement: used to define a class
– Begins with Public Class <class name>
– Ends with End Class
• Class Name list box: lists the names of objects
(controls) included in the user interface
• Method Name list box: lists the events to which
the selected object is capable of responding
• When you select a control from the Class Name list
box and a method name, a code template for the
event appears in the Code Editor window
• Syntax: rules of the language
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The Code Editor Window (cont'd.)
• Keyword: a word with special meaning in a
programming language
• Event code template has a procedure header and
a procedure footer
• Event’s procedure header:
– Begins with keywords Private Sub
– Procedure name includes object name and event
name
– Handles clause indicates for which objects’ events
this code will execute
• Sub procedure: block of code that performs a task
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The Code Editor Window (cont'd.)
Figure 1-21: Code template for the exitButton’s Click event procedure
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The Me.Close() Instruction
• Me.Close() instruction: closes the current form
at run time
– If the current form is the only form, the application is
terminated
• Me keyword: refers to the current form
• Method: predefined VB procedure that can be
invoked (called) when needed
• Sequential processing: each line is executed in
sequence
– Also called a sequence structure
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The Me.Close() Instruction (cont'd.)
Figure 1-22: Me.Close() instruction entered in the Click event procedure
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Saving a Solution
• An asterisk appears on the designer and Code
Editor tabs if a change was made since the last
time the solution was saved
Figure 1-23: How to save a solution
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Starting and Ending an Application
• Startup form: the form to be displayed when the
application starts
Figure 1-24: How to specify the startup form
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Starting and Ending an Application
(cont'd.)
Figure 1-25: Project Designer window
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Starting and Ending an Application
(cont'd.)
Figure 1-26: How to start an application
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Starting and Ending an Application
(cont'd.)
Figure 1-27: Result of starting the Wizard Viewer application
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Starting and Ending an Application
(cont'd.)
• When you start a VB application, the IDE creates
an executable file
• Executable file:
– Can be run outside of Visual Studio 2010
– Has a file extension of .exe
– Stored in the project’s bin\Debug folder
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Starting and Ending an Application
(cont'd.)
Figure 1-25: How to end an application
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Assigning a Value to a Property
During Run Time
• Properties window is used to set property values at
design time
• Assignment statement: assigns a value to a
variable or property of a control
– Used to set property values at run time
• String: zero or more characters enclosed in
quotation marks
• Assignment operator: the = sign
• Value of the expression on the right of the = sign is
assigned to the object and property on the left of
the = sign
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Using an Assignment Statement
(cont'd.)
Figure 1-29: Assignment statements entered in the Code Editor window
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Printing the Code and User Interface
Figure 1-30: How to print the code and interface during design time
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Closing the Current Solution
• Closing a solution closes all projects and files in
that solution
– You are prompted to save any files that have
unsaved changes
Figure 1-31: How to close a solution
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Opening an Existing Solution
• Only one solution can be open at any one time
• If a solution is already open, opening a different
one will close the currently open solution
Figure 1-32: How to open an existing solution
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Coding Errors
• Bug: an error in a program’s code
• Debugging: the process of locating and correcting
bugs in a program
• Syntax error: occurs when you break one of the
programming language’s rules
– Most syntax errors are caused by typing errors
• Rest the mouse pointer on the mistyped instruction
to see details about the error
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Coding Errors (cont’d.)
Figure 1-33: Syntax error in the exitButton’s Click event procedure
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Coding Errors (cont’d.)
Figure 1-34: Syntax error message
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Coding Errors (cont’d.)
• Syntax errors should be corrected before starting
an application
• If you start an application with a syntax error, a
dialog box appears
– Click No to open the Error List window
Figure 1-35: Dialog box
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Coding Errors (cont’d.)
Figure 1-36: Result of starting an application that contains a syntax error
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Programming Tutorial 1
Figure 1-54: Result of starting the Wizard application
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Programming Tutorial 2
Figure 1-67: Result of clicking the Abby button
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Programming Example
Figure 1-68: User interface
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Summary
• Object-oriented programming language allows
programmers to use objects to accomplish a goal
• Object: can be seen, touched, or used and has
attributes that control its appearance and behavior
• Class: a pattern from which an object can be
created
• Applications created in Visual Studio 2010 are
composed of solutions, projects, and files
• Windows Form Designer window: used to create
GUI applications
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Summary (cont'd.)
• A form is the foundation for the user interface
• Windows Form object is instantiated from the
Windows Form class
• Solution Explorer window: displays names of
projects and files in the solution
• Properties window: lists an object’s properties
• All class definitions are contained in namespaces
• System.Windows.Forms namespace contains
definition of the Windows Form class and class
definitions for objects added to a form
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Summary (cont'd.)
• Name property: used to refer to an object in code
• Text property of a form: specifies the text to be
displayed in the title bar of the form and in the
taskbar when running
• Form’s StartPosition property sets the position of
the form when it first appears at run time
• Recommended font is Segoe UI in 9-point size
• Toolbox: contains tools for creating the GUI
• A control’s Text property value is displayed inside
the control
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Summary (cont'd.)
• Controls on a form can be selected, sized, moved,
deleted, or locked at design time
• Label control: contains text that a user cannot edit
• Button control: performs an immediate action when
clicked
• Picture box control: displays an image on a form
• Format menu provides options for aligning and
sizing controls on a form
• Event procedure: the code that tells an object how
to respond to an event
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Summary (cont'd.)
• Use the Class Name and Method Name list boxes
to select an object and event to code
• Code Editor: provides code templates for each
object’s event procedures
• Me.Close() instruction: can terminate an
application
• Computer automatically creates an executable file
when you start a Visual Basic application in the IDE
• Use an assignment statement to assign a value to
a property during run time
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Summary (cont'd.)
• You should print your application’s code and its
user interface
• Closing a solution closes all projects and files in it
• The process of locating and correcting errors
(bugs) in a program is called debugging
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