Inheritance Abstraction Encapsulation Polymorphism Cohesion and Coupling Object-Oriented Modeling Exercises: Object-Oriented Modeling with C# and .NET Framework

3. Fundamental Principles of OOP

5. Inheritance

10. Inheritance – Example Person +Name: String +Address: String Employee +Company: String +Salary: double Student +School: String Base class Derived class Derived class

23. Abstraction

27. Abstraction in .NET – Example System.Object System.MarshalByRefObject System.ComponentModel.Component System.Windows.Forms.Control System.Windows.Forms.ButtonBase System.Windows.Forms.Button

32. UML Class Diagram – Example Shape #Position:Point struct Point +X:int +Y:int +Point interface ISurfaceCalculatable +CalculateSurface:float Rectangle -Width:float -Height:float +Rectangle +CalculateSurface:float Square -Size:float +Square +CalculateSurface:float FilledSquare -Color:Color +FilledSquare struct Color +RedValue:byte +GreenValue:byte +BlueValue:byte +Color FilledRectangle -Color:Color +FilledRectangle

34. Encapsulation

39. Polymorphism

45. Polymorphism – Example override CalcSurface() { return size * size; } override CalcSurface() { return PI * radius * raduis; } Abstract class Abstract action Concrete class Overriden action Overriden action Figure +CalcSurface() : double Square -x : int -y : int -size : int Circle -x : int -y : int -radius: int

46. Polymorphism – Example (2) abstract class Figure { public abstract double CalcSurface(); } abstract class Square { public override double CalcSurface() { return … } } Figure f1 = new Square(...); Figure f2 = new Circle(...); // This will call Square.CalcSurface() int surface = f1.CalcSurface(); // This will call Square.CalcSurface() int surface = f2.CalcSurface();

47. Polymorphism Live Demo

48. Class Hierarchies: Real World Example

53. Calculator Classes TextBox Paint() «interface» IPaintable -location -size -text -bgColor -faceColor -font Control Container Form Calculator AbstractButton Button CheckBox RadioButton MainMenu MenuItem Panel

54. Cohesion and Coupling