Dart Mixin

main.dart

// Dart 会先 Extend 继承
// 之后才会以线性 linear 的方式去 Mixin
// linear 意味着最后一个 with 的 mixins 的 functions 会覆盖前面的

class A {
  void a() {
    print(runtimeType.toString() + ": a");
  }
}

class A1 {
  void a() {
    print(runtimeType.toString() + ": a1");
  }
}

class B_With_A_A1 with A, A1 {}

class B1_With_A1_A with A1, A {}

class B2_With_A_A1_Override with A, A1 {
  @override
  void a() {
    print(runtimeType.toString() + ": b2");
  }
}

class C {
  void a() {
    print(runtimeType.toString() + ": c");
  }
}

class C0_Extends_C extends C {}
class C0_Extends_C_Override extends C {
  @override
  void a() {
    print(runtimeType.toString() + ": c0");
  }
}

class C1_Extends_C_With_A_A1 extends C with A, A1 {}

class C2_Extends_C_With_A1_A extends C with A1, A {}

class C3_Extends_C_With_A_A1_Override extends C with A, A1 {
  @override
  void a() {
    print(runtimeType.toString() + ": c3");
  }
}

void main() {
  A a = A();
  A1 a1 = A1();
  
  B_With_A_A1 b = B_With_A_A1();
  B1_With_A1_A b1 = B1_With_A1_A();
  B2_With_A_A1_Override b2 = B2_With_A_A1_Override();
  
  C0_Extends_C c0 = C0_Extends_C();
  C0_Extends_C_Override c0_override = C0_Extends_C_Override();
  C1_Extends_C_With_A_A1 c1 = C1_Extends_C_With_A_A1();
  C2_Extends_C_With_A1_A c2 = C2_Extends_C_With_A1_A();
  C3_Extends_C_With_A_A1_Override c3 = C3_Extends_C_With_A_A1_Override();

  a.a();
  a1.a();
  print('');
  
  b.a();
  b1.a();
  b2.a();
  print('');
  
  c0.a();
  c0_override.a();
  c1.a();
  c2.a();
  c3.a();
}

使用 DartPad 去运行 https://dartpad.cn/?null_safety=true

观察不同情况下的 output