委托系列二

委托基本步骤

1. 声明委托

2. 实例化委托,传递的参数和返回值与委托一致

3. 调用委托(Invoke)

无返回值无参数的委托

    class Program
    {
        public delegate void DelegateGreeting();
        
        public static void Greeting()
        {
            Console.WriteLine("早上好");
        }
        static void Main(string[] args)
        {
            DelegateGreeting delegateGreeting = new DelegateGreeting(Greeting);
            delegateGreeting.Invoke();
        }
    }

带参数和返回值的委托

    class Program
    {
        public delegate int DelegateAdd(int x,int y);
        
        public static int Add(int x,int y)
        {
            return x + y;
        }
        static void Main(string[] args)
        {
            DelegateAdd delegateAdd = new DelegateAdd(Add);
　　　　　　　// DelegateAdd delegateAdd = Add;
            Console.WriteLine(delegateAdd.Invoke(1, 2)); ;
        }
    }