static void Main(string[] args)
{
Factory <Dog> dogMaker = MakeDog;
//不能隐式转换 虽然Dog派生自Animal,
//但Factory<Dog>并没有从Factory<Animal>派生,
//这两个委托对象是同级的
// Factory<Animal> animalMaker = dogMaker;//错误
//Factory<Animal> animalMaker = MakeDog;
//协变
NewFactory <Dog> newDogMaker = MakeDog;
NewFactory <Animal> newAnimalMaker = newDogMaker;
//逆变
Action1 <Animal> act1 = ActOnAnimal;
Action1 <Dog> dog1 = act1;
//Action1<Animal> animalAction = ActOnDog;//错误
Action1 <Dog> dogAction = ActOnAnimal;
}
public void TestNewFactory()
{
IFactory <TestObject> factory = new NewFactory <TestObject>();
Assert.IsFalse(ReferenceEquals(factory.Create(), factory.Create()));
}
public void TestNewFactory()
{
IFactory<TestObject> factory = new NewFactory<TestObject>();
Assert.IsFalse(ReferenceEquals(factory.Create(), factory.Create()));
}
