学习base关键字

base 关键字用于从派生类中访问基类的成员：

• 调用基类上已被其他方法重写的方法。
• 指定创建派生类实例时应调用的基类构造函数。

一、

public class Person
        {
            protected string ssn = "444-555-666";
            protected string name = "chenyu";

            public virtual void ShowInfo()
            {
                Console.WriteLine("ssn:{0}",ssn);
                Console.WriteLine("name:{0}", name);
            }
        }

        public class Emplyee:Person
        {
            public string id = "1234567";
            public override void ShowInfo()
            {
                base.ShowInfo();
                Console.WriteLine("id:{0}",id);
            }
        }

二、

   public class MyBase
        {
            int num;
            public MyBase()
            {
                Console.WriteLine("in MyBase()");
            }

            public MyBase(int i)
            {
                num = i;
                Console.WriteLine("in MyBase(int i)");
            }

            public int GetNum()
            {
                return num;
            }
        }

        public class MyDerive : MyBase
        {
            public MyDerive()
            {
                
            }

            public MyDerive(int i)
            { }
        }
        public class C:MyDerive
        {
            public C()
            { }

            public C(int i)
                : base(i)
            {
 
            }
        }