1. Microsoft Visual Basic: Reloaded
Chapter One
An Introduction to Visual Basic

2. Overview
What Is a Computer?
Machine, Assembly and High-Level Languages
Visual Basic & Other High-Level Languages
Object Technology
The Internet and the World Wide Web
Introduction to Microsoft .NET
Language and Syntax
Visual Studio IDE
Solutions and Projects
Creating a New Project
Examples

3. What Is a Computer?
A computer is a device that can perform calculations and make logical decisions much faster than humans can.
Computers process data, using sets of instructions called computer programs.
These programs guide computers through orderly sets of actions that are specified by people known as computer programmers.

4. What Is a Computer?
A computer is composed of various devices known as hardware:
keyboard
screen
mouse
hard drives
memory
DVD drives
printer
processing units
The programs that run on a computer are referred to as software.

5. Computers can be thought of as being divided into six units:
Computer Components
Computers can be thought of as being divided into six units:
Input unit: This “receiving” section of the computer obtains information from input devices.
Input can come from devices such as the keyboard and the mouse.
Output unit: This “shipping” section of the computer takes information that the computer has processed and places it on various output devices.
Output can be displayed on screens, printed on paper, played on audio/video devices, and transmitted over the Internet.

6. Computer Components
Memory unit: This “warehouse” section of the computer stores data while an application is running. Its information is immediately available for processing.
To be executed, computer programs must be in memory.
The memory unit retains information until it can be sent to output devices.
Often, the memory unit is called either memory or primary memory.
Random-access memory (RAM) is an example of primary memory.
Primary memory is usually volatile, which means that it is erased when the machine is powered off.

7. Computer Components
Central processing unit (CPU): The CPU supervises the operation of the other sections.
Arithmetic and logic unit (ALU): The ALU (a part of the CPU) performs calculations and makes decisions.
Secondary storage unit: This unit is the “warehousing” section of the computer.
Devices such as hard drives, CD-ROM drives, DVD drives, and USB memory sticks are secondary storage units.
These normally hold programs or data that other units are not actively being used.
The computer can retrieve this information when it is needed later in time. Secondary storage is nonvolatile.
Information in secondary storage takes much longer to access than information in primary memory.

8. Machine, Assembly and High-Level Languages
Programmers write instructions in programming languages. Some of these are directly understandable by computers, and others require intermediate translation steps.
Computer languages that are in use today can be divided into three general types:
machine languages
assembly languages
high-level languages

9. Machine, Assembly and High-Level Languages
A computer can directly understand only its own machine language.
As the “natural language” of a particular computer, machine language is defined by the computer’s hardware design. Machine languages are machine dependent.
Machine languages generally consist of streams of numbers (ultimately reduced to 1s and 0s in the binary number system).

10. Machine, Assembly and High-Level Languages
The following section of a machine-language program demonstrates the incomprehensibility of machine language to humans:
Machine-language programming proved to be slow and error prone.

11. Machine, Assembly and High-Level Languages
Programmers began using English-like abbreviations to represent the computer’s basic operations.
These abbreviations formed the basis of assembly languages. LOAD BASEPAY ADD OVERPAY STORE GROSSPAY

12. Machine, Assembly and High-Level Languages
Translator programs called assemblers convert assembly-language programs to machine language.
Although it is clearer to humans, computers cannot understand assembly-language code until it is translated into machine language.
Assembly languages still require many instructions to accomplish even the simplest tasks.

13. Machine, Assembly and High-Level Languages
To speed up the programming process, high-level languages were developed.
Programs called compilers convert high-level-language programs into machine language.
High-level languages look almost like everyday English and contain common mathematical notations.
grossPay = basePay + overTimePay
Visual Basic is one of the world’s most popular high-level programming languages.

14. Visual Basic
Visual Basic evolved from BASIC (Beginner’s All-purpose Symbolic Instruction Code), which was developed as a language for writing simple programs quickly and easily.
When Bill Gates founded Microsoft Corporation in the 1970s, he implemented BASIC on several early personal computers.

15. Visual Basic
In the late 1980s and the early 1990s, Microsoft developed the Microsoft® Windows® graphical user interface (GUI).
Visual Basic was introduced by Microsoft in 1991 to make programming Windows applications easier.

16. Visual Basic
Visual Basic is a so-called object-oriented, event-driven visual programming language.
Programs are created with the use of a software tool called an Integrated Development Environment (IDE). (Visual Studio)
The latest versions of Visual Basic are fully object oriented and respond to user-initiated events such as mouse clicks, keystrokes and timers.
In Visual Studio, it is convenient to make programs by dragging and dropping predefined objects like buttons and textboxes.

17. Visual Basic
Microsoft introduced its .NET strategy in 2000.
The .NET platform allows applications to be distributed to a variety of devices.
Software components created in different .NET programming languages can communicate with one another.
In 2000, Microsoft announced C#. The C# programming language was designed specifically for the .NET platform. Like Visual Basic, C# is object oriented and has access to .NET’s library.

18. Almost any noun can be reasonably represented as a software object.
Object Technology
Object technology is a packaging scheme for creating meaningful software units.
Almost any noun can be reasonably represented as a software object.
Objects:
have properties such as color, size and weight
perform actions such as moving, sleeping or drawing
A class specifies the general format of its objects, and the properties and actions available to an object depend on its class.

19. Object Technology
Procedural programming languages focused on actions (verbs) rather than objects (nouns).
Object-oriented languages more naturally reflects the way in which we perceive the world.
This has resulted in significant productivity gains.
Properly designed classes can be reused on future projects
Using libraries of classes reduces the amount of effort required to implement new systems
The production of software is more understandable because it is better organized and has fewer maintenance requirements.

20. Object Technology
Instead of worrying about the details of how objects are implemented, you can focus on the behaviors and interactions of objects.
Visual Basic is one of the world’s most widely used object-oriented languages.

21. The Internet and the World Wide Web
In the late 1960s, ARPA rolled out plans to network the main computer systems of ARPA-funded universities and research institutions.
This became known as the ARPAnet, the grandparent of today’s Internet.
Its main benefit proved to be the capability for quick and easy communication via what came to be known as electronic mail ( ).

22. The Internet and the World Wide Web
The protocol for communicating over the ARPAnet became known as the Transmission Control Protocol (TCP).
TCP ensured that messages, consisting of pieces called “packets,” were properly routed from sender to receiver, arrived intact and were assembled in the correct order.
One challenge was to enable different networks to communicate with each other.
ARPA accomplished this by developing the Internet Protocol (IP), which created the current architecture of the Internet.
The combined set of protocols is now called TCP/IP.

23. The Internet and the World Wide Web
The World Wide Web is a collection of hardware and software associated with the Internet.
In 1989, Tim Berners-Lee of CERN began to develop a technology for sharing information via “hyperlinked” text documents called HyperText Markup Language (HTML).
He also wrote communication protocols such as HyperText Transfer Protocol (HTTP).
In October 1994, Berners-Lee founded the World Wide Web Consortium, devoted to developing technologies for the World Wide Web.

24. The Internet and the World Wide Web
The Internet and the web will surely be listed among the most important creations of humankind.
Today’s applications can be written to communicate among the world’s computers. This is the focus of Microsoft’s .NET strategy.
The Internet and the World Wide Web:
make information instantly and conveniently accessible,
and allow individuals and small businesses to achieve worldwide exposure.

25. Introduction to Microsoft .NET
In June 2000, Microsoft announced its .NET initiative
The .NET initiative permits developers to create applications in any .NET-compatible language.
Part of the initiative includes Microsoft’s ASP.NET.
The .NET strategy extends the idea of software reuse to the Internet.
Visual programming enables .NET programmers to create applications using prepackaged graphical components.

26. The Microsoft .NET Framework:
executes applications and web services
contains a class library (Framework Class Library)
and provides many other programming capabilities.
The .NET framework is a platform with which you can develop software applications and libraries called managed applications; it provides you with the compiler and tools you need to build, debug, and execute managed applications.
Prior to this approach, unmanaged applications had to manage their own services which sometimes led to security holes and data corruption.

27. .NET Framework
CLR: Common Language
WCF: Windows Communication Foundation
WPF: Windows Presentation Foundation
WF: Windows Workflow Foundation
LINQ: Language Integrated Query
Cardspace: Manages online identities
AJAX: Asynchronous JavaScript and XML
REST: Representational State Transfer

28. .NET Framework

29. Spoken Languages and Syntax
Sprechen Sie Englisch?
¿Habla ingles?
Você fala inglês?
OO-day ou-yay eak-Spay Eng-hay ish-lay?

30. Examples of Programming Languages
C: fast, efficient code
Java: platform independence
BASIC: ease of use
Visual Basic: user interface design using forms
Perl: text manipulation

31. Visual Basic.NET syntax
If x>5 Then MessageBox.Show("I am greater than 5.") Else MessageBox.Show ("I am not greater than 5.") End If

32. C# Syntax
if (x>5) { MessageBox.Show ("I am greater than 5."); } else MessageBox.Show ("I am not greater than 5.");

33. Learning a Programming Language
Syntax
Structure
Rules
Punctuation
Reserved Words (keywords) eg. If, Else
Visual Basic.NET is NOT case sensitive. MyCase is the same as myCase and MYCASE.
Comment lines start with an apostrophe (')

34. Visual Studio IDE
Visual Studio® is Microsoft’s integrated development environment (IDE) for creating, running and debugging applications.
The IDE allows you to create applications by dragging and dropping existing building blocks into place.
This technique is called visual programming.
It is a Rapid Application Development (RAD) tool because it is focused on productivity.

35. Visual Studio Languages
Visual Basic.NET
C# (pronounced C-Sharp)
J# (pronounced J-Sharp)
C++ (pronounced C plus plus)
ASP.NET (web page creation)

36. Some Advantages of Visual Studio IDE
Greatly reduces amount of code you must write
Automatically colors code depending what it is
Comments are Green
Keywords are Blue
Organizes code in separate files
IntelliSense
Code Snippets
Real-time compiler feedback
Red squiggle under code indicates a syntax error

37. Solutions and Projects
Visual Basic organizes applications into solutions and projects.
Solutions contain one or more projects.
A project is a group of related files, such as code and images that might make up a program.

38. Solutions, Projects, and Files

39. Creating a New Project
Select either File > New Project…, which creates a new project, or File > Open Project…, which opens an existing project.
From the Start Page, under the Start section, click the link New Project… or Open Project….
Click either the New Project Button or the Open File Button.

40. Working With a Project
The Solution Explorer window displays a list of the files in a project and the projects in a solution.
The Properties window displays an object’s attributes, such as its size, color and position. The Properties window allows you to set object properties visually without writing code.
Using visual programming, you can “drag and drop” controls onto the Form from the Toolbox.
Properties icon
Object Browser icon
Solution Explorer icon
Toolbox icon

41. Properties Window
Object’s name (Form1)
Object’s class (System.Windows.Forms.Form)
Component object box
Down arrow for selecting Form or control objects
Categorized icon
Alphabetical icon
Items that have been changed from their default values (by the user or by Visual Studio) are listed in bold
Selected property
Design category
Description of selected property
Properties (left column)
Property values (right column)
Figure 2.22 | Properties window displaying a Form’s properties.

42. Form Controls

43. Hello World!
Console App: Console.WriteLine("Hello World") Windows Form App: MessageBox.Show("Hello World!")

44. Create Webrowser control
Web Browser
Create form
Text: My Own Browser
Width/Height: (640,480)
Create Webrowser control
Width/Height: (607,385)
X/Y: (12,12)
Name: myBrowser
Create textbox
Width/Height: (526,20)
X/Y: (12,411)
Name: txtURL

45. myBrowser.Navigate(txtURL.Text)
Web Browser (cont.)
Create button
Text: GO
X/Y: (544,411)
Name: btnGo
Add this line of code to the button:
myBrowser.Navigate(txtURL.Text)