Classes, Interfaces, Structs, and Enumerations

You design a C# class using a class in PowerDesigner. Structures are classes with the <<structure>> stereotype, and enumerations are classes with the <<enumeration>> stereotype.

• C# classes can contain events, variables, constants, methods, constructors, properties, and indexers. The following specific classes are also supported in PowerDesigner:

  • New class is used to declare a member with the same name or signature as an inherited member. To design a new class, you have to set the class new extended attribute to True. In the following example, class DialogBox inherits from class Window. Class Window contains an inner classifier Control, and so does class DialogBox. You do not want class DialogBox to inherit from the control defined in Window, to do so, you have to set the new extended attribute to True, in the Control class inner to DialogBox:

    { public class DialogBox : Window { public new class Control { } } }

  • Abstract class is equivalent to an abstract class. To design this type of class you need to create a class and select the Abstract check box in the General tab of the class property sheet.

    { public abstract class Client { private int Name; private int ID; } }

  • Sealed class is equivalent to a final class. To design this type of class, you need to create a class and select the Final check box in the General tab of the class property sheet.

    { public sealed class SealedClass { private int A1; private int A2; } }

  Note: You design a C# nested type using an inner class or interface.

• C# interfaces are modeled as standard interfaces. They can contain events, properties, indexers and methods; they do not support variables, constants, and constructors.

• Structures can implement interfaces but do not support inheritance; they can contain events, variables, constants, methods, constructors, and properties. The following struct contains two attributes:

  { public struct Point { public int New() { return 0; } private int x; private int y; } }

• Enumeration class attributes are used as enumeration values. The following items must be set:

  • Data Type - using the EnumDataType extended attribute of the enumeration (for example Byte, Short, or Long)

  • Initial Expression - using the Initial Value field of an enum attribute

  For example:

  { public enum Color : colors { Red, Blue, Green, Max = Blue } }