Microsoft Visual Basic 2005: Reloaded Second Edition Chapter 1 An Introduction to Visual Basic 2005
Objectives After studying this chapter, you should be able to: Explain the history of programming languages Define the terminology used in object-oriented programming Explain the role of the.net Framework class library and Common Language Runtime (CLR) Create a Visual Basic 2005 Windows-based application Manage the windows in the Integrated Development Environment (IDE) Microsoft Visual Basic 2005: Reloaded, Second Edition 2
Objectives (continued) Set the properties of an object Add a control to a form Use the Label, Button and PictureBox tools Enter code in the Code Editor window Save a solution Microsoft Visual Basic 2005: Reloaded, Second Edition 3
Objectives (continued) Start and end an application Print a project s code Write an assignment statement Close and open an existing solution Microsoft Visual Basic 2005: Reloaded, Second Edition 4
Programmers Programs: instructions given to computers Programmers: people who write programs Applications programmers: write and maintain programs to handle specific tasks Systems programmers: write and maintain programs that run the system, such as operating systems, device drivers, utilities Microsoft Visual Basic 2005: Reloaded, Second Edition 5
A Brief History of Programming Languages Programming languages: used to communicate with the computer Machine language (or machine code): Instructions are written in 0s and 1s Only way to communicate directly with the computer Assembly languages: use mnemonics for instructions Mnemonics: alphabetic abbreviations for instructions Microsoft Visual Basic 2005: Reloaded, Second Edition 6
A Brief History of Programming Languages (continued) Assembler: program that converts assembly language instructions into machine code High-level languages: Instructions resemble English language Require an interpreter or compiler to convert highlevel language to machine code Interpreter: translates high-level instructions lineby-line as the program runs Compiler: translates entire program into machine code before running the program Microsoft Visual Basic 2005: Reloaded, Second Edition 7
A Brief History of Programming Languages (continued) Procedure-oriented program: one that focuses on individual tasks and their sequence Object-oriented program: one that focuses on objects the program can use to accomplish its goal Microsoft Visual Basic 2005: Reloaded, Second Edition 8
OOP Terminology OOP: Object-oriented programming OOD: Object-oriented design Object: Represents a real-world entity Attributes (or properties): describe the object Methods: behaviors or operations the object can perform Class: blueprint used to create an object Microsoft Visual Basic 2005: Reloaded, Second Edition 9
OOP Terminology (continued) Encapsulation: the class contains all the attributes and behaviors of the object created from the class Instance: an object created from a class Abstraction: the hiding of internal details of an object Exposed: attributes and behaviors that are not hidden Inheritance: ability to create one class from another Microsoft Visual Basic 2005: Reloaded, Second Edition 10
OOP Terminology (continued) Derived class: a new class created from another by inheritance Base class: the class used to create the new class Polymorphism: allows the same instructions to be carried out differently depending on the object Microsoft Visual Basic 2005: Reloaded, Second Edition 11
OOP Terminology (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 12
Visual Studio 2005 Integrated Development Environment (IDE): Contains all the tools and features needed to create, run, and test programs Includes an editor and compiler Visual Studio 2005: IDE used to create Windows or Web-based programs Includes Visual Basic 2005, Visual C++ 2005, Visual C# 2005, and Visual J# 2005 Microsoft Visual Basic 2005: Reloaded, Second Edition 13
Visual Studio 2005 (continued) Application: program or suite of programs Windows-based application: Has a Windows user interface Runs on a desktop computer User interface: what the user sees and interacts with when using an application Microsoft Visual Basic 2005: Reloaded, Second Edition 14
Visual Studio 2005 (continued) Web-based application: Has a Web user interface Runs on a server Use a computer browser to access it Microsoft.NET Framework 2.0: a platform on which you create applications.net languages: the programming languages included in Visual Studio.NET applications: applications created with Visual Studio Microsoft Visual Basic 2005: Reloaded, Second Edition 15
Visual Studio 2005 (continued).net Framework class library: Contains an extensive set of classes for use in.net applications Reduces development time by providing reusable code Provides consistency among applications Microsoft Visual Basic 2005: Reloaded, Second Edition 16
The Common Language Runtime.NET language compilers translate program statements into a Microsoft Intermediate Language, also called Intermediate Language (IL) Common Language Runtime (CLR): Manages the execution of IL instructions Just-in-time (JIT) compiler: translates IL into machine code CLR allows compiled IL to be reused, regardless of which.net language was used to create it Microsoft Visual Basic 2005: Reloaded, Second Edition 17
The Common Language Runtime (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 18
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 part of the solution Microsoft Visual Basic 2005: Reloaded, Second Edition 19
Solutions, Projects, and Files (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 20
Starting Microsoft Visual Studio 2005 Microsoft Visual Basic 2005: Reloaded, Second Edition 21
Starting Microsoft Visual Studio 2005 (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 22
Starting Microsoft Visual Studio 2005 (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 23
Creating a Visual Basic 2005 Windows-Based Application Microsoft Visual Basic 2005: Reloaded, Second Edition 24
Creating a Visual Basic 2005 Windows-Based Application (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 25
Creating a Visual Basic 2005 Windows-Based Application (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 26
Managing the Windows in the IDE Microsoft Visual Basic 2005: Reloaded, Second Edition 27
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 when using the application Windows Form object (or form): Adds other objects such as buttons and textboxes to create the GUI Instance of the Windows Form class Automatically instantiated when you create an application Microsoft Visual Basic 2005: Reloaded, Second Edition 28
The Windows Form Designer Window (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 29
The Solution Explorer Window Solution Explorer window: Displays a list of projects contained in this solution Displays the items contained in each project Microsoft Visual Basic 2005: Reloaded, Second Edition 30
The Solution Explorer Window (continued) Project Designer window: Open by right-clicking on project folder Allows you to set options for the project Contains 9 tabs with groups of options Microsoft Visual Basic 2005: Reloaded, Second Edition 31
The Solution Explorer Window (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 32
The Solution Explorer Window (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 33
The Solution Explorer Window (continued) Source file: a file containing program instructions Code: program instructions Form file: a file containing code associated with a Windows form object Microsoft Visual Basic 2005: Reloaded, Second Edition 34
The Properties Window Properties window: displays properties of selected object Default property values are assigned when an object is created Microsoft Visual Basic 2005: Reloaded, Second Edition 35
The Properties Window (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 36
The Properties Window (continued) 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 Settings box: Right column containing the current value of each property Microsoft Visual Basic 2005: Reloaded, Second Edition 37
Properties of a Windows Form Object Microsoft Visual Basic 2005: Reloaded, Second Edition 38
Properties of a Windows Form Object (continued) Class definition: block of code that defines the attributes and behaviors of an object Namespace: defines a group of related classes Dot member access operator: the period that separates words in an object s name Name property: used to refer to an object in code Hungarian notation: naming convention using a 3 or more character prefix to represent the object type Camel casing: lowercase prefix, uppercase first letter of each word Microsoft Visual Basic 2005: Reloaded, Second Edition 39
Properties of a Windows Form Object (continued) Pascal case: First letter and first letter of each word 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 Splash screen: first image to appear when application starts Microsoft Visual Basic 2005: Reloaded, Second Edition 40
Properties of a Windows Form Object (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 41
The Toolbox Window Toolbox: Contains tools used to create an application Each tool represents a class from which to instantiate objects Controls: Objects displayed on a form Are represented as icons in the toolbox Can be locked in place on the form Control names use camel casing Microsoft Visual Basic 2005: Reloaded, Second Edition 42
The Toolbox Window (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 43
The Toolbox Window (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 44
The Label Tool Label tool: represents a label control Label control: Displays text that user cannot edit Used as prompts to explain controls or display output Microsoft Visual Basic 2005: Reloaded, Second Edition 45
The Label Tool (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 46
The Label Tool (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 47
The Button Tool Button tool: represents a button control Button control: Performs an immediate action when clicked Microsoft Visual Basic 2005: Reloaded, Second Edition 48
The Button Tool (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 49
The Button Tool (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 50
The Code Editor Window Events: user actions while program is running Event procedure: set of instructions to be executed when an event occurs Code editor: used to enter programming code Microsoft Visual Basic 2005: Reloaded, Second Edition 51
The Code Editor Window (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 52
The Code Editor Window (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 53
The Code Editor Window (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 54
The Code Editor Window (continued) Keyword: has special meaning in a programming language Sub procedure: block of code that performs a task Event s Procedure header: Begins with keyword Private Procedure name includes object name and event name Handles clause indicates for which objects events this code will execute Microsoft Visual Basic 2005: Reloaded, Second Edition 55
The Me.Close Method Me.Close method: closes the current form Method: predefined VB procedure that can be invoked (called) Sequential processing: each line is executed in sequence Microsoft Visual Basic 2005: Reloaded, Second Edition 56
The Me.Close Method (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 57
Saving a Solution Microsoft Visual Basic 2005: Reloaded, Second Edition 58
Starting and Ending an Application Startup form: the form to be displayed when the application starts Microsoft Visual Basic 2005: Reloaded, Second Edition 59
Starting and Ending an Application (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 60
Starting and Ending an Application (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 61
Starting and Ending an Application (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 62
Starting and Ending an Application (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 63
Starting and Ending an Application (continued) Executable file: Can be run outside of Visual Studio 2005 Has file extension of.exe Microsoft Visual Basic 2005: Reloaded, Second Edition 64
Starting and Ending an Application (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 65
Using an Assignment Statement Assignment statement: assigns a value to a variable or property of a control Assignment operator: the = symbol Microsoft Visual Basic 2005: Reloaded, Second Edition 66
Using an Assignment Statement (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 67
Using an Assignment Statement (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 68
Printing Your Code Microsoft Visual Basic 2005: Reloaded, Second Edition 69
Closing the Current Solution Closing a solution closes all projects and files in that solution Microsoft Visual Basic 2005: Reloaded, Second Edition 70
Closing the Current Solution (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 71
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 Microsoft Visual Basic 2005: Reloaded, Second Edition 72
Opening an Existing Solution (continued) Microsoft Visual Basic 2005: Reloaded, Second Edition 73
Programming Tutorial Microsoft Visual Basic 2005: Reloaded, Second Edition 74
Programming Example Microsoft Visual Basic 2005: Reloaded, Second Edition 75
Summary Program: directions given to a computer Programming languages have progressed from machine language to assembly language to highlevel languages Compiler: converts high-level languages to machine instructions Object: can be seen, touched, or used Objects have attributes (properties) and behaviors (methods and events) Microsoft Visual Basic 2005: Reloaded, Second Edition 76
Summary (continued) Class: a pattern from which an object can be instantiated Class encapsulates an object s attributes and behaviors IDE: interactive development environment Windows Form Designer window: used to create GUI applications Solution Explorer window: shows names of projects and files in the solution Microsoft Visual Basic 2005: Reloaded, Second Edition 77
Summary (continued) Properties window: sets an object s property values 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 Toolbox: contains tools for creating the GUI Label control: contains text that a user cannot edit Event: occurs when user interacts with GUI elements Microsoft Visual Basic 2005: Reloaded, Second Edition 78
Summary (continued) Event procedure: the code that runs when an event occurs Button control: performs an immediate action when clicked Code editor: provides code templates for each object s event procedures Microsoft Visual Basic 2005: Reloaded, Second Edition 79