oop - 如何在 Dart 中定义接口(interface)？

Question

在 Java 中，我可能有一个接口(interface) IsSilly以及实现它的一种或多种具体类型:

public interface IsSilly {
    public void makePeopleLaugh();
}

public class Clown implements IsSilly {
    @Override
    public void makePeopleLaugh() {
        // Here is where the magic happens
    }
}

public class Comedian implements IsSilly {
    @Override
    public void makePeopleLaugh() {
        // Here is where the magic happens
    }
}

Dart 中的这段代码等价于什么？

看完官方docs在类里面，Dart 似乎没有原生 interface类型。那么，一般的 Dartisan 是如何实现接口(interface)隔离原理的呢？

Answer 1

在 Dart 中有一个概念 implicit interfaces .

Every class implicitly defines an interface containing all the instance members of the class and of any interfaces it implements. If you want to create a class A that supports class B’s API without inheriting B’s implementation, class A should implement the B interface.

A class implements one or more interfaces by declaring them in an implements clause and then providing the APIs required by the interfaces.

所以你的例子可以像这样在 Dart 中翻译:

abstract class IsSilly {
  void makePeopleLaugh();
}

class Clown implements IsSilly {
  void makePeopleLaugh() {
    // Here is where the magic happens
  }
}

class Comedian implements IsSilly {
  void makePeopleLaugh() {
    // Here is where the magic happens
  }
}