Design Patterns

Design patterns are solutions to software design problems you find again and again in real-world application development. Patterns are about reusable designs and interactions of objects..

The 23 Gang of Four (GoF) patterns are generally considered the foundation for all other patterns. They are categorized in three groups: Creational, Structural, and Behavioural

To give you a head start, the C# source code for each pattern is provided in 2 forms: structural and real-world. Structural code uses type names as defined in the pattern definition and UML diagrams. Real-world code provides real-world programming situations where you may use these patterns.

A third form, .NET optimized, demonstrates design patterns that exploit built-in .NET 4.5 features, such as, generics, attributes, delegates, reflection, and more.

Creational Patterns:

Abstract Factory :Creates an instance of several families of classes

Builder: Separates object construction from its representation

Factory Method :Creates an instance of several derived classes

Prototype: A fully initialized instance to be copied or cloned

Singleton: A class of which only a single instance can exist

Structural Patterns

Adapter : Match interfaces of different classes

Bridge: Separates an object’s interface from its implementation

Composite: A tree structure of simple and composite objects

Decorator : Add responsibilities to objects dynamically

Facade : A single class that represents an entire subsystem

Flyweight:  A fine-grained instance used for efficient sharing

Proxy: An object representing another object.

Behavioural Patterns

Chain of Resp.: A way of passing a request between a chain of objects

Command :Encapsulate a command request as an object

Interpreter :   A way to include language elements in a program

Iterator: Sequentially access the elements of a collection

Mediator: Defines simplified communication between classes

Memento: Capture and restore an object's internal state

Observer : A way of notifying change to a number of classes

State: Alter an object's behavior when its state changes

Strategy: Encapsulates an algorithm inside a class

Template Method: Defer the exact steps of an algorithm to a subclass

Visitor: Defines a new operation to a class without change