abstract子类中不能添加新字段吗?

Question

 public abstract class Person
    {        protected string name;
        protected int age;        public Person(string name, int age)
        {
            this.name = name;
            this.age = age;        }        public abstract void SayHi();
    }public class Chinese : Person
    {
        private string address;
        public Chinese(string name,int age,string address)
        {
            this.name = name;
            this.age = age;
            this.address = address;
        }        public override void SayHi()
        {
            Console.Write("My name is {0},{1} old,{3}", name, age,address);
        }
    }这样为什么不可以

Answer 1

public Chinese(string name,int age,string address) : base(name, age)
{
      this.address = address;
}

Answer 2

构造函数不能被继承
使用Base调用基类方法或属性时,会沿着继承链逐级往上寻找,以最近为原则,找到就调用,找不到就报错 。

Answer 3

也可以这样
 public abstract class Person
    {        protected string name;
        protected int age;
        public Persion(){
           ....
        }
        public Person(string name, int age)
        {
            this.name = name;
            this.age = age;        }        public abstract void SayHi();
    }public class Chinese : Person
    {
        private string address;
        public Chinese(string name,int age,string address)
        {
            this.name = name;
            this.age = age;
            this.address = address;
        }        public override void SayHi()
        {
            Console.Write("My name is {0},{1} old,{3}", name, age,address);
        }
    }