SOLID包含哪些设计原则？

1、单一职责原则：A class should have one, and only one, reason to change，一个类只能因为一个理由被修改。 2、开闭原则：Entities should be open for extension, but closed for modification，对扩展开放，对修改关闭。 3、里氏替换原则：Functions that use pointers of references to base classes must be able to use objects of derived classes without knowing it，子类可以替换父类。 4、接口隔离原则：A client should not be forced to implement an interface that it doesn’t use，不能强制客户端实现它不使用的接口，应该把接口拆的尽可能小。 5、依赖倒置原则：Abstractions should not depend on details. Details should depend on abstractions，抽象不依赖于细节，而细节依赖于抽象。