design patern

Question

What is design patern in .net? Why use it??

Muralidharan Deenathayalan · Answer

In software engineering  a design pattern is a general reusable solution to a commonly occurring problem in software design . A design pattern is not a finished design that can be transformed directly into code . It is a description or template for how to solve a problem that can be used in many different situations. Object-oriented design patterns typically show relationships and interactions between classes or objects  without specifying the final application classes or objects that are involved. Design patterns reside in the domain of modules and interconnections. At a higher level there are architectural patterns that are larger in scope usually describing an overall pattern followed by an entire system. http://www.dofactory.com/Patterns/Patterns.aspx 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 Behavioral 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