23个GOF设计模式中，你了解了多少？实际使用中又有多少？
| 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 |
http://www.dofactory.com/Patterns/Patterns.aspx