未提供必须形参对应的实参怎样解决

摘自：未提供必须形参对应的实参怎样解决

 abstract public class User
    {
        private IMediator mediator;

        public IMediator GetMediator()
        {
            return mediator;
        }

		//构造函数
        public User(IMediator mediator)
        {
            this.mediator = mediator;
        }

        public abstract void Work();
    }

    public class User1 : User
    {
    	//如果没有:base(mediator) 会报错未提供必须形参对应的实参
    	//加上以后 就把这里的mediator传到父类User的构造函数里了
    	//先调用父类的构造函数 再走子类的构造函数
        public User1(IMediator mediator):base(mediator)
        {
            //this.mediator = mediator;
        }
        public override void Work()
        {
            Console.WriteLine("user1 exe!");
        }
    }