万物weiyi 2019-11-05
Mixins are a way of reusing a class’s code in multiple class hierarchies.
void main() {
Animal animal = Animal();
Bird().fly();
Fish().swim();
Duck().move();
Duck().swim();
Duck().fly();
}
mixin CanSwim {
void swim() {
print(‘change poisiton by swimming‘);
}
}
mixin CanFly {
void fly() {
print(‘change poisiton by flying‘);
}
}
class Animal {
void move () {
print(‘change position‘);
}
}
class Fish extends Animal with CanSwim{
@override
void move () {
super.move();
}
}
class Bird extends Animal with CanFly{
@override
void move () {
super.move();
}
}
class Duck extends Animal with CanFly, CanSwim{
@override
void move () {
super.move();
}
}