C# for Java Developers

C# for Java Developers

• 1.
  C#  for  Java  Developers   Jussi  Pohjolainen   Tampere  University  of  Applied  Sciences  
• 2.
  Overview   •  Ecma  and  ISO  Standard   •  Developed  by  MicrosoD,  uses  in  .NET  and   WP7   •  Most  recent  version  is  C#  4.0  
• 3.
  Versions  
• 4.
  Common  Language  Infrastructure  (CLI)  
• 5.
  CLI   •  CLI  is  an  open  specificaRon  that  describes   executable  code  and  runRme  environment   •  CLI  is  core  of   –  MicrosoD  .NET  Framework   –  Mono  (Open  Source)   –  Portable.net  (Open  Source)    
• 6.
  CTS,  CLS,  VES,  CIL   •  Common  Type  System  (CTS)   –  A  set  of  data  types  and  operaRons  that  are  share  by  all   CTS-­‐compliant  programming  languages,  such  as  C#  and  VB   •  Common  Language  SpecificaRon  (CLS)   –  Set  of  base  rules  to  which  any  language  targeRng  the  CLI   should  conform.     •  Virtual  ExecuRon  System  (VES)   –  VES  loads  and  executes  CLI-­‐compaRble  programs   •  Common  Intermediate  Language  (CIL)   –  Intermediate  language  that  is  abstracted  from  the   plaXorm  hardware  (In  Java:  class)  
• 7.
  Mono:OSX  »  C#  File  
• 8.
  Mono:OSX  »  Building  
• 9.
  Mono:OSX  »  Running  
• 10.
  .NET  on  Windows  7   Add  C:WindowsMicrosoft.NETFrameworkv3.5 to  path!  
• 11.
  Common  Language  RunRme:  Mac   Dropbox  –   folder  
• 12.
  Common  Language  RunRme:  Win   And  run   the  .exe  in   Windows!  
• 13.
  Almost  the  Same  but  Not  Quite   C#  
• 14.
  Keywords   •  Single  rooted  class  hierarchy:  all  objects   inheritate  System.Object   •  Almost  every  keyword  in  Java  can  be  found   from  C#   –  super -> base –  instanceof -> is –  import -> using –  extends / implements -> : •  Otherwise,  pre`y  much  the  same  
• 15.
  Memory  Handling  and  RunRme   •  Memory  Handling   –  Most  objects  in  C#  to  heap  using  new   –  CLR  handles  garbage  collecRons   •  RunRme   –  C#  is  compiled  to  intermediate  langage  (IL)   –  IL  runs  on  top  of  CLR   –  IL  code  is  always  naRvely  compiled  before  running  
• 16.
  OO   •  No  global  methods,  just  like  in  Java   •  Interface  is  pure  abstract  class   •  No  mulRple  inheritance    
• 17.
  Main   usingSystem; class A { public static void Main(String[] args){ Console.WriteLine("Hello World"); } }
• 18.
  Compiling  Several  Files  in  C#   C:CodeSample> csc /main:A /out:example.exe A.cs B.cs C:CodeSample> example.exe Hello World from class A C:CodeSample> csc /main:B /out:example.exe A.cs B.cs C:CodeSample> example.exe Hello World from class B
• 19.
  Inheritance:  Base  Class   using System; abstract public class Figure { private int x; private int y; public Figure(int x, int y) { this.x = x; this.y = y; } public void SetX(int x) { this.x = x; } public void SetY(int y) { this.y = y; } public int GetY() { return y; } public int GetX() { return x; } public abstract double CalculateSurfaceArea(); }
• 20.
  Inheritance:  Interface   interfaceIMove { void MoveTo(int x, int y); }
• 21.
  Inheritance   public classRectangle : Figure, IMove { private int width; private int height; public Rectangle(int x, int y, int width, int height) : base(x,y) { this.width = width; this.height = height; } public void MoveTo(int x, int y) { SetX( GetX() + x ); SetY( GetY() + y ); } public override double CalculateSurfaceArea() { return width * height; } public static void Main(String [] args) { Rectangle r = new Rectangle(4, 5, 10, 10); Console.Write( "Rectangle x: " ); Console.Write( r.GetX() ); r.MoveTo(5, 0); Console.Write( "nRectangle y: " ); Console.Write( r.GetX() ); Console.Write( "nRectangle Surface Area: " ); Console.Write( r.CalculateSurfaceArea() ); Console.Write( "n" ); } }
• 23.
  Run  Time  Type  IdenRficaRon   public static void Main(String [] args) { Object rectangleObject = new Rectangle(4, 5, 10, 10); // Type cast from Object to Rectangle Rectangle temp1 = rectangleObject as Rectangle; // Check if cast was successfull if(temp1 != null) { Console.Write("Success: Object was casted to Rectangle!"); temp1.SetX(0); } }
• 24.
  ProperRes   public classRectangle : Figure, IMove { private int height; private int width; public int Width { get { return width; } set { if(value > 0) { width = value; } else { Console.WriteLine("Value was not set."); } } } public Rectangle(int x, int y, int width, int height) : base(x,y) { this.width = width; this.height = height; } … public static void Main(String [] args) { Rectangle r = new Rectangle(5,5,10,10); r.Width = 10; Console.Write(r.Width); // Value was not set r.Width = -5; } }
• 25.
  Alias   using Terminal= System.Console; class Test { public static void Main(string[] args){ Terminal.WriteLine("Please don’t use this"); } }
• 26.
  Namespaces   using System; namespacefi.tamk.tiko.ohjelmistotuotanto { public class Test { public static void method() { Console.Write("ohjelmistotuotanton"); } } } namespace fi.tamk.tiko.pelituotanto { public class Test { public static void method() { Console.Write("pelituotanton"); } } } class App { public static void Main(String [] args) { fi.tamk.tiko.ohjelmistotuotanto.Test.method(); fi.tamk.tiko.pelituotanto.Test.method(); } }
• 27.
  Constant  Variables   • const int VARIABLE = 10;
• 28.
  Variable  Length  Parameters  and  foreach   using System; public class Params { public static void Method(params int[] array) { foreach(int num in array) { Console.Write(num); Console.Write("n"); } } public static void Main(String [] args) { Method(1,2,3,4,5); Method(1,2); int [] myArray = {1,2,3,4}; Method(myArray); } }
• 29.
  OperaRon  Overloading   usingSystem; public class MyNumber { private int value; public MyNumber(int value) { this.value = value; } public static MyNumber operator+(MyNumber number1, MyNumber number2) { int sum = number1.value + number2.value; MyNumber temp = new MyNumber(sum); return temp; } public static void Main(String [] args) { MyNumber number1 = new MyNumber(5); MyNumber number2 = new MyNumber(5); MyNumber sum = number1 + number2; Console.Write(sum.value); } }
• 30.
  ParRal  Types   • The  parRal  types  feature  enables  one  to   define  a  single  class  across  mul/ple  source   files!   •  So  one  class  can  be  declared  in  several  files!