namespace ConsoleApplication1
{
    class Employee
    {
        public Employee()
        {
            Console.WriteLine("父类的构造方法");
        }
        public virtual void EmpInfo()
        {
            Console.WriteLine("父类的虚拟方法");
        }
    }
    class DervEmployee : Employee
    {
        public DervEmployee()
        {
            Console.WriteLine("子类的构造方法");
        }
        public override void EmpInfo()
        {
            base.EmpInfo();//base关键字将在下面拓展中提到
            Console.WriteLine("子类的重写方法");
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            DervEmployee objDervEmployee = new DervEmployee();
               objDervEmployee.EmpInfo();
                //注意：objDervEmployee派生类的实例是赋给Employee类的objEmployee的引用，
                // 所以objEmployee引用调用EmpInfo()方法时 还是调用DervEmployee类的方法
               Employee objEmployee = new Employee();
               objEmployee.EmpInfo();
        }
    }
}