1. Advanced Programming C#
Introduction

2. C# Genealogy Object Oriented Advanced Object Oriented
Elementary Procedural
Advanced Procedural
Special Procedural
Eiffel
Fortran
Algol 68 C
C++ C#
Cobol
PL/I
Pascal
Ada 95
Java
Ada 83

3. Program
A program is a machine-compatible representation of an algorithm
If no algorithm exists for performing a task, then the task can not be performed by a machine
Programs and algorithms they represent collectively referred to as Software

4. Programming Languages
Machine language
Strings of 0 and 1, machine dependent
Assembly language
English like abbreviations representing elementary operations
Assemblers needed to convert assembly into machine language
High-level languages (C, C++, Java, …)
Single statements accomplish substantial tasks
Compiler needed to convert the program into machine language
Some languages are interpreted (executed without the need for compilation)

5. Example Machine Code Fragment
A number specifies what action the computer should take.

6. Example Assembly Code Fragment
movl (%edx,%eax), %ecx
movl 12(%ebp), %eax
leal 0(,%eax,4), %edx
movl $nodes, %eax
movl (%edx,%eax), %eax
fldl (%ecx)
fsubl (%eax)
movl 8(%ebp), %eax
Symbols to help programmers to remember the words.

7. Programming Languages
Examples of High-level languages
FORTRAN (FORmula TRANslator) in 1950s
scientific and engineering applications
COBOL (Common Business Oriented language) in 1959
Commercial applications for manipulation of large amounts of data
BASIC (Beginner’s All Purpose Symbolic Instruction Code)
Familiarize novices with programming techniques (in mid-1960s)
Pascal (17th century mathematician Blaise Pascal) in 1971
Teaching structured programming in academic environments

8. Programming LanguagesC
Bell labs  Dennis Ritchie, 1973
C++
Bjarne Stroustrup, 1980
Hybrid OOP
Java
Sun Microsystems (formally announced in May 1995)
Pure OOP
Web programming

9. What is C#?
C# (pronounced "C sharp") is an object-oriented language that is used to build applications for the Microsoft .NET platform
C# is designed by Microsoft to combine the power of C/C++, Java and the productivity of Visual Basic
The goal of C# and the .NET platform is to shorten development time
by allowing developers to spend their time working on the application logic instead of low level programming details

10. Why C#? support so-called safe internet programming
simpler than other object-oriented languages [C++]
safe and robust --- no core dump or dead console
good graphics package
related to C and C++
good client-server and network support
good for your future job

11. C# A component oriented language
C# is the first “component oriented” language
Component concepts are first class:
Properties, methods, events
Design-time and run-time attributes
Integrated documentation using XML
Enables one-stop programming
No header files, IDL, etc.
Can be embedded in web pages

12. C# Everything really is an object
Traditional views
C++, Java: Primitive types are “magic” and do not interoperate with objects
Smalltalk, Lisp: Primitive types are objects, but at great performance cost
C# unifies with no performance cost
Deep simplicity throughout system
Improved extensibility and reusability
New primitive types: Decimal, SQL…
Collections, etc., work for all types

13. Learning C# Just like learning any new language Syntax: “new words”
Grammar: how to put them together
Programming: telling a coherent story
Library: use plots already written
Picking up Java and C++ after C# should be easy!

14. Programming Languages C#
Microsoft announced the .NET initiative (June 2000) and C#
.NET enables web-based applications to be distributed to a great variety of devices and desktop computers
Allows applications created in various programming languages to communicate with each other
Designed to ease migration to .NET (roots in C and C++)
Event-driven, fully OO visual programming language

15. Microsoft’s .NET Technologies
Many languages run on .NET framework C#, C++, J#, Visual Basic even have Python (see IronPython)

16. Example C++/C#/Java Code Fragment
bool DetermineNeighbor(int i, int j) {
double distanceX = (nodes[i].x - nodes[j].x);
double distanceY = (nodes[i].y - nodes[j].y);
double distanceSquare = disx * disx + disy * disy;
double distance = sqrt(distanceSquare);
if (distance < radius)
return true;
else
return false; }
You do not need to understand the exact meaning of this program, just the feeling.

17. Visual Studio HTML 5 / CSS 3 / Javascript
Full HTML 5 and CSS 3 specs supported
Quirks for downlevel browsers fully supported
CSS and JavaScript now first class citizens in editor
DOCTYPE
JavaScript
Based on Chakra engine in IE 9
Directly tell us which JS files to provide intellisense

18. C# compiling.
C# is executed indirectly through an abstract computer architecture called the CLR.
CLR => Common Language Runtime.
Abstract, but well defined.
C# programs are compiled to an IL.
Also called MSIL, CIL (Common Intermediate Language) or bytecode.

19. Compiling C# Source Code
C# file names have the extension .cs
To create the IL file, we need to compile the .cs file using the csc (using the command line), followed by the name of the source file
The result is a file with the same name but the .exe extension, which is called an assembly
The assembly file contains all the information that the common runtime needs to know to execute the program
We can also create multi-file assemblies using an assembly linker, see the following link for more details:

20. C# Compilation and Execution
C# source
code
MSIL C#
compiler
Machine
code
Just in time
compiler

21. C# and Language Comparison 60% Java, 10% C++, 10% VB, 20% new
As in Java
Object-orientation (single inheritance)
Namespaces (like packages)
Interfaces
Strong typing
Exceptions
Threads
Garbage collection
Reflection
Dynamic loading of code
As in C++
Operator overloading
Pointer arithmetic in unsafe code
Some syntactic details
As in VB
Properties
Events
RAD development

22. OOP Structured programming versus OOP
Objects have properties (attributes) and perform actions
Objects are defined in classes (represent groups of related objects)
Programs are more understandable
better organized programs

23. Introduction to C# Console applications Windows applications
No visual components
Only text output
Two types
MS-DOS prompt (Used in Windows 95/98/ME)
Command prompt (Used in windows 2000/NT/XP)
Windows applications
Forms with several output types
Contain Graphical User Interfaces (GUIs)

24. New Project dialog.

25. New Project dialog. New project dialogue C# .NET project
Group of related files, images, and documentations
C# .NET solution
Group of projects creating one or a group of applications
Windows Applications
Anything that runs in the Windows OS
Microsoft Word
Microsoft Internet Explorer

27. Simple Program

28. A First C# Program: 'Hello World'
using System;
public class HelloWorld {
public static void Main(string[] args)
// This is a single line comment
/* This is a
multiple
line comment */
Console.WriteLine("Hello World"); }

29. Simple Program
Execution of the Welcome1 program.

30. Windows Application menu title bat tabs menu bar active tab
Solution Explorer
Form (windows application)
Properties window

31. Windows Application IDE after a new project The form Tabs
Grey rectangle in window
Represents the project’s window
Part of the GUI or Graphical User Interface
Graphical components for user interaction
User can enter data (input)
Shows user instructions or results (output)
Tabs
One tab appears for each open document
Used to save space in the IDE

32. Simple Program: Displaying Text and an Image

33. Simple Program: Displaying Text and an Image
Project type
Project name
Click to change project location
Project location
Creating a new Windows application.

36. Simple Program: Displaying Text and an Image
Name and type of object
Selected property
Property value
Property description
Setting the form’s Text property.

37. Simple Program: Displaying Text and an Image
Resize the form
Click and drag one of the forms size handles
Enables handles are white
Disables handles are gray
The grid in the background will not appear in the solution
Change the form’s background color
The BackColor determines the form’s background color
Dropdown arrow is used to set the color
Add a label control to the form
Controls can be dragged to the form
Controls can be added to the form by double clicking
The forms background color is the default of added controls

38. Simple Program: Displaying Text and an Image
Title bar
grid
Disabled sizing handle
Mouse pointer over a sizing handle
Enabled sizing handle
Form with sizing handles.

39. Simple Program: Displaying Text and an Image
Current color
Custom palette
Down arrow
Changing property BackColor.

40. Simple Program: Displaying Text and an Image
Label control
New background color
Adding a new label to the form.

41. Simple Program: Displaying Text and an Image
Set the label’s text
The Text property is used to set the text of a label
The label can be dragged to a desired location
Or Format > Center In Form > Horizontal can also be used to position the label as in in this example
Set the label’s font size and align text
The Font property changes the label’s text (Fig. 2.23)
The TextAlign property to align the text
Add a picture box to the form
Picture boxes are used to display pictures
Drag the picture box onto the form

42. Simple Program: Displaying Text and an Image
Label centered with updated Text property
Label in position with its Text property set.

43. Simple Program: Displaying Text and an Image
Ellipsis indicate dialog will appear
Properties window displaying the label’s properties.

44. Simple Program: Displaying Text and an Image
Current font
Font size
Font window for selecting fonts, styles and sizes.

45. Simple Program: Displaying Text and an Image
Text alignment option
Top-center alignment option
Centering the text in the label.

46. Simple Program: Displaying Text and an Image
Updated Label
New PictureBox
Inserting and aligning the picture box.

47. Simple Program: Displaying Text and an Image
Insert an image
The Image property sets the image that appears
Pictures should be of type .gif, .jpeg, or .png
The picture box is resizable to fit the entire image
Save the project
In the Solution Explorer select File > Save
Using Save All will save the source code and the project
Run the project
In run mode several IDE features are disabled
Click Build Solution in the Build menu to compile the solution
Click Debug in the Start menu or press the F5 key

48. Simple Program: Displaying Text and an Image
Image property value (no image selected)
Image property of the picture box.

49. Simple Program: Displaying Text and an Image
Selecting an image for the picture box.

50. Simple Program: Displaying Text and an Image
Newly inserted image (after resizing the picture box)
Picture box after the image has been inserted.

51. Simple Program: Displaying Text and an Image
Start button
Run mode
Design form
End button
Design form (grid)
Running application
run mode, with the running application in the foreground.

52. Simple Program: Displaying Text and an Image
Terminating the program
Click the close button (x in the top right corner)
Or click the End button in the toolbar

53. Major Language Differences
Automatic memory management
Garbage Collection
No pointers
Everything inherits from System.Object
Additional language constructs to aid in implementing common patterns:
Iterators – foreach and yield statements
Data encapsulation – Properties
Function pointers or Functors – delegates
Observer Design Pattern – events
Aspect-oriented programming – Attributes (loosely)
Functional programming – LINQ and anonymous methods

54. Other Language Differences
Conditionals must evaluate to a Boolean
No pointers. Use the dot “.” to access both namespaces and fields/methods.
All fields are initialized by the CLR (zero for value types, null for reference types).
The switch statement can take bool’s , enum’s, integral types and strings.
Expressions must be useful (no a==b;).

55. Simple Program // A first program in C#. using System; class Welcome1{
static void Main( string[] args )
Console.WriteLine( "Welcome to C# Programming!" );
} }

56. Constructions of Note using namespace class
like import in Java: bring in namespaces
namespace
disambiguation of names
like Internet hierarchical names and C++ naming
class
like in C++ or Java
single inheritance up to object

57. Constructions of Note static void Main() Console.Write(Line)
Defines the entry point for an assembly.
Four different overloads – taking string arguments and returning int’s.
Console.Write(Line)
Takes a formatted string: “Composite Format”
Indexed elements: e.g., {0}
can be used multiple times
only evaluated once
{index [,alignment][:formatting]}

58. Common Type System (CTS)
From MSDN

59. Atomic Data

60. Built-in Types C# predefined types The “root” object Logical bool
Signed sbyte, short, int, long
Unsigned byte, ushort, uint, ulong
Floating-point float, double, decimal
Textual char, string
Textual types use Unicode (16-bit characters)

61. Type System Value types Reference types Primitives int i;
Enums enum State { Off, On }
Structs struct Point { int x, y; }
Reference types
Classes class Foo: Bar, IFoo {...}
Interfaces interface IFoo: IBar {...}
Arrays string[] a = new string[10];
Delegates delegate void Empty();

62. C# Comments Comments can be created using //…
Multi-lines comments use /* … */
Comments are ignored by the compiler

63. C# Keywords Words that cannot be used as variable or class names
Have a specific unchangeable function within the language
Example: class

64. Classes And Structs class CPoint { int x, y; ... }
struct SPoint { int x, y; ... }
CPoint cp = new CPoint(10, 20);
SPoint sp = new SPoint(10, 20); 10 sp 20 cp
CPoint 10 20

65. C# Classes
Class names can only be one word long (i.e. no white space in class name )
Class names are capitalized, with each additional English word capitalized as well (e.g., MyFirstProgram )
Each class name is an identifier
Can contain letters, digits, and underscores (_)
Cannot start with digits
Can start with the at symbol

66. C# Class Methods Class bodies start with a left brace ({)
Class bodies end with a right brace (})
Methods
Building blocks of programs
The Main method
Each console or windows application must have exactly one
All programs start by executing the Main method
Braces are used to start ({) and end (}) a method

67. C# Statements Anything in quotes (“) is considered a string
Every statement must end in a semicolon (;)

68. C#

69. NameSpaces
You import namespaces when you want to be able to refer to classes by their short name, rather than full name
For example, import System.XML allows XmlDataDocument and XmlNode rather than System.XML.XmlDataDocument and System.XML.XmlNode to be in your code.

70. Events
Events are a way for an object to communicate with those that are interested in what it has to offer, like a button has a click event
Interested parties use Event Handlers, which are a way of subscribing to the event