.NET基础之自定义泛型分析(3)

//Cow的子类，有一个自己的方法Fly
class SuperCow : Cow
{
        public SuperCow(string name) : base(name)
        {
        }
 
        public void Fly()
        {
            Console.WriteLine("{0} is flying!", name);
        }
 
        public override void MakeANoise()
        {
            Console.WriteLine("{0} says 'I am supercow!'", name);
        }
}

类准备好了之后，我们可以开始定义我们的泛型了：

复制代码 代码如下:

//继承了迭代器接口，这样方便使用Foreach 约束它的类型为Animal及其子类
public class Farm<T>:IEnumerable<T> where T : Animal
{
        private List<T> animals = new List<T>();
 
        public List<T> Animals
        {
            get
            {
                return animals;   
            }
        }
        //迭代器
        public IEnumerator<T> GetEnumerator()
        {
            return animals.GetEnumerator();
        }
 
        IEnumerator IEnumerable.GetEnumerator()
        {
            return animals.GetEnumerator();
        }
 
        //执行所有animal的MakeANoise()
        public void MakeNoises()
        {
            foreach (T animal in animals)
            {
                animal.MakeANoise();
            }
        }
        //执行所有animal的Feed()
        public void FeedTheAnimals()
        {
            foreach (T animal in animals)
            {
                animal.Feed();
            }
        }
        //获得animals中的cow
        public Farm<Cow> GetCows()
        {
            Farm<Cow> cowFarm = new Farm<Cow>();
            foreach (T animal in animals)
            {
                if (animal is Cow)
                {
                    cowFarm.Animals.Add(animal as Cow);
                }
            }
            return cowFarm;
        }
}

泛型定义好了，我们用写代码来调用它：

复制代码 代码如下: