Basic and Introduction of Visual Programming Subject

1. B Y
A Q S A H A Y A T
D E P A R T M E N T O F C O M P U T E R S C I E N C E
Visual Programming
7/13/2021
1

2. Brief History of Visual Basic
 Evolved from BASIC
 Beginner’s
 All-Purpose
 Symbolic
 Instruction
 Code
 Developed in mid-1960s
7/13/2021
2

3. Visual Basic
 Evolved into Visual Basic in 1991
 Major Features:
 IDE (Integrated Development Environment)
 GUI’s
 Event Handling
 Object Oriented Programming
 Exception Handling
 Rapid Application Development (RAD)
7/13/2021
3

4. VB.Net
 Introduced in 2000
 Features:
 Enhance language interoperability
 Availability of Internet features
 Web services
 Enhanced object orientation
 Including library of components
 Platform independence
 Not backwardly compatible
7/13/2021
4

5. .Net Strategy
 Web Services
 Applications can be used over the Internet
 Includes ASP.Net technology
 Software Reuse
 Allows programmers to concentrate on their particular
specialties without having to implement every component of
every application.
 Universal Data Access
 Central location for data
7/13/2021
5

6. Reusability
 Building-block approach
 Central to the OOP concept.
 Improves performance
 More reliable programs
 Avoids reinventing the wheel…
7/13/2021
6

7. .Net Framework
 Manages and executes applications and Web
services
 Contains a class library
 Framework Class Library or FCL
 Enforces security
 Visual programming
 Microsoft .Net Framework Link
7/13/2021
7

8. .Net Framework Layers
7/13/2021
8
VB C++ C# JScript
Common Language Specification
ASP.NET Windows Forms
Data and XML
Base Class Library
Common Language Runtime
Windows COM+ Services

9. Common Language Infrastructure (CLI)
 Contains info about storage of
 data types
 Data that have predefined characteristics
 Ex. Dates, percentages or currency amounts
 Objects
 Has been standardized
 Making it easier to create the .NET Framework for other
platforms.
7/13/2021
9

10. Common Language Runtime (CLR)
 Executes Visual Basic .Net programs
 Programs are compiled into machine-specific instructions
using two steps:
 Program is compiled into Microsoft Intermediate Language
(MSIL).
 Defines instructions for the CLR
 Then another compiler in the CLR, called the JIT compiler (just-
in-time compiler) translates the MSIL into machine code, for the
particular platform, creating a single application
7/13/2021
10

11. Why two compilations?
 Provides
 Portability between operating systems
 Interoperability between languages
 Execution-management features
 Memory management
 Security
7/13/2021
11

12. Platform Independence
 .Net framework provides the ability of a program
to run (without any modification) across
multiple platforms.
 The .NET Framework is actually a set of classes called
base classes.
 Saves Time and Money!
 Don’t reinvent the same code for multiple platforms
 Targets wider audience
 Avoids the expensive process of porting
(converting software from one platform to another)
7/13/2021
12

13. Language Interoperability
 Programs from different languages are all
compiled into MSIL
 The different parts are combined to create one
program
 MSIL allows the .NET Framework to be language
independent or .Net compliant
 .Net programs are not tied to any particular programming
language.
7/13/2021
13

14. Benefits of Language Interoperability in
.Net?
 VB.Net, C#, Visual C++.Net programmers can all
work on same project
 Old and new components can work together
 Permits code reusability (code doesn’t have to be
rewritten)
 CLR’s execution-management features
 Code loading and execution
 Application isolation
 Memory management
 Security
7/13/2021
14

15.  Exception handling
 Interoperability
 Managing security, memory and other features, relieving
programmer of these responsibilities
 Provides huge library of classes providing
reusability
 Framework Class Library (FCL)
7/13/2021
15

16. Software Engineering Observation
 Reuse of existing classes when building new
classes and programs saves
 time, money & effort
 Reuse also helps in building more reliable and
effective systems
 Why?
 Because existing classes and components go through extensive
testing, debugging and performance tuning.
7/13/2021
16

17. Views of VB Between
Vista vs Windows 7 & 8
7/13/2021
17
Vista Windows 7 Windows 8

18. Introduction to
Programming Development
7/13/2021
18

19. People Involved in Program Development
 Programmer
 Person who solves the problem and writes the instructions for
the computer
 Client
 The person/organization who is responsible for
requesting/purchasing the program
 User
 Any person who uses the program
7/13/2021
19

20. Designing Your Program
 Critically important to design before beginning to
code
 Coding first is like putting the cart before the horse.
 Doesn’t matter the size of the program -- design first!
7/13/2021
20

21. Program Planning Steps
1. Analyze – define the problem
2. Design – plan the solution to the problem
3. Design the Interface – select the objects that will be used
4. Code – translate the algorithm into a programming
language
5. Debug & Test – locate and remove any errors in the
program
6. Complete the documentation – Internal & External
7/13/2021
21

22. Key Steps to Creating a Visual Program
7/13/2021
22
Plan the tasks
How it should work
Design user interface
Write the code
Debug and Test
Document & Distribute
How it should look
Repeat Steps 1 & 2
Prepare test criteria
Put program into use

23. Design Process Results
 Even for a small program, the design process should
produce the following results:
 A concise list of tasks to be performed by the program
 Deadlines for components
 Clarification of the dependence of one part of the program on
another
 The criteria for testing the program
7/13/2021
23

24. Problem Solving
 Developing the solution to a problem
 Algorithm
 a step by step series of instructions to solve a problem
 Example:
 How would you give instructions to someone to find your
house?
7/13/2021
24

25. Divide-and-Conquer Method
 Used in problem solving
 take a large problem and break it into smaller problems
 Solve the small problems first
7/13/2021
25

26. Tools Used in Design
 Hierarchy Charts/Structure
Charts
 Flowcharts/UML
 Graphically depict the logical
steps to accomplish a task and
indicate how the steps relate to
each other
 Pseudocode
 Uses English-like
phrases with some
Visual Basic terms to
outline the task.
 Control Structures
 Sequence
 Decision/Selection
 Repetition/Loops/
Iteration
7/13/2021
26

27. Pseudocode Example
Program: Determine average grade of a class
Initialize Counter and Sum to 0 Initialization
Do While there are more data
Get the next Grade
Add the Grade to the Sum Processing
Increment the Counter
Loop
Compute Average = Sum / Counter
Display Average Output
7/13/2021
27

28. Flowchart Symbols
7/13/2021
28

29. Flowchart Symbols (continued)
7/13/2021
29

30. Flowchart
Example
7/13/2021
30

31. Statement Structures
 Sequence
 Execute instructions one after another
 Decision
 Allows us to ask questions and execute different instructions
based on result
 Looping
 a series of instructions are executed repeatedly
7/13/2021
31

32. Decision Flow Chart
7/13/2021
32

33. Looping Flow Chart
7/13/2021
33

34. Visual Programming Benefits
 Provides the programmer with the ability to create
graphical user interfaces (GUIs).
 Allows the programmer to write much less code
 Does not require the programmer to be a Windows
expert
 Provides Rapid Application Development (RAD) –
code can be developed faster & cheaper
7/13/2021
34

35. Programming Languages-Procedural, Event
Driven and Object Oriented
 Procedural—Cobol, Fortran, Basic
 Program specifies exact sequence of all operations
 Event Driven (VB 6.0 and previous)
 Contain some elements of Object oriented programming but not all
 User controls sequence
 Click event
 Double Click event
 Change event
7/13/2021
35

36. Object Oriented Programming (OOP) (VB .NET)
VB is an object-oriented programming
language.
 Means you work with objects in building an
application.
 Examples: Form objects, Button objects, TextBox
objects, Label objects, ListBox objects, PictureBox
objects, and more.
7/13/2021
36

37. VB is also termed an event-driven programming
language because you will write program code that
responds to events that are controlled by the system
user. Example events include:
 Clicking a button or menu.
 Opening or Closing a form.
 Moving the mouse over the top of an object such as a
text box.
 Moving from one text box to another.
7/13/2021
37

38. The Object Model
In VB you will work with objects, which have
properties, methods, and events. Each object is
based on a class.
 Objects equate to Nouns
 Forms are windows
 Controls are components contained inside a form
 Properties equate to Adjectives
 Color or size of a Form
 Methods are like Verbs
 Typical methods include Close, Show and Clear
 Events occur when the user takes action
 User clicks a button, User moves a form
7/13/2021
38

39. The Object Model
 Classes are templates used to create a new object
 Classes contain the definition of all available properties, methods,
and events
 Each new object created is based on a class
 Creating three new buttons makes each button a instance of the
Button class
7/13/2021
39

40. Terminology Definition
Object A thing – like a noun in English. Examples include forms and controls you place on forms such
as buttons, text boxes, and icons.
Property Objects have properties – like adjectives in English. Properties describe object behaviors.
Examples of properties include Text, Name, BackColor, Font, and Size.
Refer to a property by the notation ObjectName.PropertyName (use the .dot notation) –
example: TotalDueTextBox.Text or AccountLabel.ForeColor.
Method Like a verb in English – these are the actions that objects exhibit. Examples include methods to
Show and Hide forms and methods to Print and Close forms.
Refer to a method with the notation ObjectName.MethodName – example Me.Close will close
the current form.
Event Events are actions usually triggered by the system user such as clicking a button; however,
events can also be triggered by the actions of objects. For example, closing a form can trigger
an event.
Class This is a really abstract term – it is a sort of template for an object. For example, all forms
belong to the Form class of object. All buttons belong to the Button class of object. Classes
include definitions for object properties, methods, and associated events. Each class is
assigned an identifying namespace within the .NET Framework Class Library.
Each new object you create is defined based on its class – the new object is called a class
instance.
7/13/2021
40

41. Object Model Analogy
 Class = automobile
 Properties = make, model, color, year
 Object = each individual car
 Object is also an Instance of the automobile class
 Methods = start, stop, speedup, slowdown
 Events = car arrives, car crashes
7/13/2021
41

42. Visual Studio .NET
 Included in Visual Studio .NET 2002, 2003,2005,
2008 ,2010and onword
 Visual Basic
 Visual C++
 Visual C# (C sharp)
 Visual J#
 Visual F#
 .NET 2.0 Framework or more
 Visual Studio .NET Editions
 Standard
 Professional
 Enterprise Developer
 Enterprise Architect
 Express
7/13/2021
42

43. System Requirements Express Edition
 Supported Operating
Systems
 Windows 7 SP3 (x32)
(This package)
 Windows 7 SP1
(x86 and x64)
 Windows 8
(x86 and x64)
 Windows Server 2008 R2
SP1 (x64)
 Windows Server 2012 (x64)
 Hardware
Requirements:
 1.6 GHz or faster processor
 1 GB of RAM (1.5 GB if running
on a virtual machine)
 5 GB of available hard disk
space
 5400 RPM hard drive
 DirectX 9-capable video card
running at 1024 x 768 or higher
display resolution
7/13/2021
43

44. Visual Studio Environment
The Visual Studio environment is where you create
and test your projects-in Visual Studio it is called an
 Integrated Development Environment (IDE)
 consists of various tools including:
 Form Designer
 Editor for entering code
 Compiler
 Debugger
 Object Browser
 Help facility
7/13/2021
44

45. The IDE Initial Screen
The Visual Studio
IDE with the
Start Page open,
as it first
appears in
Windows , with
an open project.
7/13/2021
45

46. Get Started
 New Project
 Opens list of existing projects
 Recent Projects
 Contains information on projects recently created or modified
 Get Started
 Focuses on using the IDE for creating programs and learning
VB.
7/13/2021
46

47. New Project Window
7/13/2021
47
Need to rename to something meaningful!
Window Form
Change Location

48. New Project
7/13/2021
48
DO NOT MOVE
Properties Window
Or
Solution Explorer Windows!!!!!

49. Visual Studio’s Main Windows
 Solution Explorer
 Properties
 Toolbox
7/13/2021
49

50. Solution Explorer
 Provides access to all of a solution’s files.
 If it’s not shown in the IDE, click the Solution
Explorer icon in the IDE , select View > Other
Windows > Solution Explorer or type <Ctrl> <Alt> L.
 Displays the solution’s contents
 When a new or existing solution is opened.
7/13/2021
50

51. Properties
Window
 4 Methods to Place
Control on Form
 Double-click
 Drag and Drop
 Click, Point, and Click
 Click, Point, and Drag
7/13/2021
51

52. IDE Menus
7/13/2021
52

53. IDE Menus cont.
7/13/2021
53

54. Toolbox
7/13/2021
54
Toolbox window
displaying
controls for the
Common Controls
group.
The pushpin in the upper
right corner is the AutoHide
feature and will “stick” the
Toolbox to visible if you want
it to remain visible during design.

55. Auto Hide
 Hides Toolbox when not in use
 Vertical push pin icon indicates auto hide is disabled.
 Click the push pin to make it horizontal and enable
auto hide.
7/13/2021
55
push pin

56. Properties Window
7/13/2021
56
Properties
Settings in
Alphabetical
Order
Selected
control
Description
pane

57. Modes
 Design Time--used when designing the user interface
and writing code
 Run Time--used when testing and running a project
 Break Time--if/when receiving a run-time error or
pause error
7/13/2021
57

58. VB Application Files
 One Solution File—think of
one solution file equals one project .sln
 Solution User Options File .suo
 Form Files .vb
 Resource File for the Form .resx
 Project Files .vbproj
 Project User Options File .vbproj.user
 Application configuration File .app.config
7/13/2021
58

59. Remark Statement
 Also known as Comment, used for documentation;
every procedure should begin with a remark
statement providing explanation
 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
`Display your information
7/13/2021
59

60. Notation
 To reference object's properties and events in code
 Object dot Property
 Form.Text, TextBox.Text
 Object dot Method/Function/Subroutine
 Form.Hide( ), TextBox.Focus( )
 To reference an object's events use an underscore
instead of a dot
 Button_Click, ListBox_TextChanged
7/13/2021
60

61. Naming Rules and Conventions
Visual Basic automatically assigns a value to the Name property of each control, for
example, Label1, Label2, Label3, or TextBox1, TextBox2, TextBox3, or Button1,
Button2, Button3. However, it is difficult to remember the difference between Label1 and
Label2 so:
 if you are going to later refer to the controls, it is best to rename them to a more
meaningful name,
 if you are not going to refer to the controls later, then just use the assigned default name
such as Label1.
When you name an object such as a Label or TextBox or Button, you must follow these rules:
 An object name can begin with an alphabetic letter or the special “underscore” character.
 An object name can include letters, digits, and underscores.
 An object name CANNOT include a space or a punctuation mark.
 An object name CANNOT be a VB reserved word such as Button, Close, or TextBox.
 An object name can contain a VB reserved word – object names such as PrintButton,
CloseButton, NameTextBox, and MajorTextBox are legal names.
7/13/2021
61

62. Pascal naming convention
The rules are:
 Begin an object name with an uppercase alphabetic character.
 Capitalize each word that is part of an object name.
 Select object names that are meaningful.
 Append the full name of the control class to the end of the name.
 Avoid abbreviations unless they are standard abbreviations such as SSN (social security
number).
 Examples of valid names: MajorTextBox, ResetButton, MessageLabel,
TotalDueTextBox, and CloseButton.
7/13/2021
62

63. Camel Casing and Hungarian naming
conventions
Camel Casing and Hungarian Naming Conventions
Control Type and
Camel Casing Naming
Suffix
Example Camel Casing
Control Names
Hungarian
Naming
Prefix
Example Hungarian
Control Names
TextBox NameTextBox,
MajorTextBox
txt txtName, txtMajor
Button ShippingButton,
ExitButton, ResetButton
btn btnShipping, btnExit,
btnReset
Label NameLabel, OutputLabel lbl lblName, lblOutput
Note: Label controls are often not renamed – they are not referred to later in
writing computer code so the default assigned name is unchanged.
7/13/2021
63