advanced programming c# introduction 1. c# genealogy fortranalgol 68cc++c# cobol eiffel javaada...

Advanced Programming

C#

Introduction

1

C# Genealogy

Fortran Algol 68 C C++ C#

Cobol

Eiffel

JavaAda 95PL/I Pascal

ElementaryProcedural

AdvancedProcedural

SpecialProcedural

ObjectOriented

AdvancedObject

Oriented

Ada 83

3

•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

Program

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)

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Example Machine Code Fragment

177312 137272 001400 026400 017400 000012 000007 004420010400 011000 000010 005023 012000 012400 000010 003426013400 000007 000430 003000 064474 064556 037164 000001024003 053051 000001 041404 062157 000545 007400 064514062556 072516 061155 071145 060524 066142 000545 002000060555 067151 000001 024026 046133 060552 060566 066057067141 027547 072123 064562 063556 024473 000526 005000067523 071165 062543 064506 062554 000001 046014 067151067543 067154 065056 073141 006141 004000 004400 000007006031 015000 015400 000001 040433 070440 067565 062564060552 060566 064457 027557 071120 067151 051564 071164060545 000555 003400 071160 067151 066164 000556 012400046050 060552 060566 066057 067141 027547 072123 064562063556 024473 000126 000041 000006 000007 000000 000000000002 000001 000010 000011 000001 000012 000000 000035000001 000001 000000 025005 000267 130401 000000 000400005400 000000 003000 000400 000000 003400 004400 006000006400 000400 005000 000000 030400 001000 000400 000000010400 000262 011002 133003 002000 000262 011002 133005002000 000261 000000 000001 000013 000000 000016 000003000000 000016 000010 000020 000020 000021 000001 000016000000 000002 000017

A number specifies what action the computer should take.

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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 leal 0(,%eax,4), %edx movl $nodes, %eax movl (%edx,%eax), %ecx movl 12(%ebp), %eax leal 0(,%eax,4), %edx movl $nodes, %eax

Symbols to help programmers to remember the words.

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•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

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•C

Bell labs Dennis Ritchie, 1973

•C++

Bjarne Stroustrup, 1980

Hybrid OOP

•Java

Sun Microsystems (formally announced in May 1995)

Pure OOP

Web programming

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

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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

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

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

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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!

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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

Microsoft’s .NET Technologies

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

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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.

Visual StudioHTML 5 / CSS 3 / Javascript HTML 5 / CSS

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

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.

http://msdn2.microsoft.com/en-us/library/z1zx9t92(VS.80).aspx

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:

http://longhorn.msdn.microsoft.com/lhsdk/ndp/tskhowtobuildmultfileassembly.aspx

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C# Compilation and Execution

C# sourcecode

MSIL

C#compiler

Machinecode

Just in timecompiler

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C# and Language Comparison60% 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

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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

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Introduction to C#

Console 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)

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New Project dialog.

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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

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Simple Program

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"); } }

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Simple Program

Execution of the Welcome1 program.

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Windows Application

tabs

menu title bat

menu bar

active tab Solution Explorer

Properties window

Form (windows application)

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Windows Application

IDE after a new project The form

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

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Simple Program: Displaying Text and an Image

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Creating a new Windows application.

Project name

Project location Click to change project location

Project type

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Setting the form’s Text property.

Name and type of object

Property value

Selected property

Property description

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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

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Form with sizing handles.

grid

Mouse pointer over a sizing handle

Enabled sizing handle

Disabled sizing handle

Title bar

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Changing property BackColor.

Down arrow

Current color

Custom palette

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Adding a new label to the form.

Label control

New background color

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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

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Label in position with its Text property set.

Label centered with updated Text property

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Properties window displaying the label’s properties.

Ellipsis indicate dialog will appear

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Font window for selecting fonts, styles and sizes.

Font size

Current font

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Centering the text in the label.

Text alignment option

Top-center alignment option

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Inserting and aligning the picture box.

Updated Label

New PictureBox

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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

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Image property of the picture box.

Image property value (no image selected)

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Selecting an image for the picture box.

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Picture box after the image has been inserted.

Newly inserted image (after resizing the picture box)

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run mode, with the running application in the foreground.

Start button

End button

Run mode Design form

Design form (grid)

Running application

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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

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

Other Language Differences

Conditionals must evaluate to a BooleanNo 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;).

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Simple Program// A first program in C#.

using System;

class Welcome1

{

static void Main( string[] args )

{

Console.WriteLine( "Welcome to C# Programming!" );

} }

Constructions of Note

using 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

Constructions of Note

static void Main() 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]}

Common Type System (CTS)

From MSDN

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Atomic Data

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)

Type System Value 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();

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C#

Comments

Comments can be created using //…

Multi-lines comments use /* … */

Comments are ignored by the compiler

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C#

Keywords

Words that cannot be used as variable or

class names

Have a specific unchangeable function

within the language

Example: class

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);

1010

2020spsp

cpcp

1010

2020

CPointCPoint

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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 (@)

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C# Class

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

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C# Statements

Anything in quotes (“) is considered a string

Every statement must end in a semicolon (;)

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C#

Escape sequence Description \n Newline. Position the screen cursor to the beginning of the

next line. \t Horizontal tab. Move the screen cursor to the next tab stop. \r Carriage return. Position the screen cursor to the beginning

of the current line; do not advance to the next line. Any characters output after the carriage return overwrite the previous characters output on that line.

\\ Backslash. Used to print a backslash character. \" Double quote. Used to print a double quote (") character. Some common escape sequences.

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.

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

advanced programming c# introduction 1. c# genealogy fortranalgol 68cc++c# cobol eiffel javaada...

Documents

x movl

x leal

x fsubl

x fldl

x symbols

compilation slide

machine programs

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