c#编程--100例

//多态性的示例 using System; class Vehicle//定义汽车类 { public int wheels; //公有成员轮子个数 protected float weight; //保护成员重量 public Vehicle(int w,float g){ wheels = w; weight = g; } public virtual void Speak(){ Console.WriteLine("w正在鸣叫!"); } } class Car:Vehicle //定义轿车类 { int passengers; //私有成员乘客数 public Car(int w,float g,int p) : base(w,g) { wheels = w; weight = g; passengers = p; } public override void Speak(){ Console.WriteLine("汽车正在鸣叫:嘀嘀!"); } } class Truck:Vehicle //定义卡车类 { int passengers; //私有成员乘客数 float load; //私有成员载重量 public Truck (int w,float g,int p,float l) : base(w,g) { wheels = w; weight = g; passengers = p; load = l; } public override void Speak(){ Console.WriteLine("卡车正在鸣叫:叭叭!"); } } class Test { public static void Main(){ Vehicle v1 = new Vehicle(3,2); Car c1 = new Car(4,2,5); Truck t1 = new Truck(6,5,3,10); v1.Speak(); v1 = c1; v1.Speak(); c1.Speak(); v1 = t1; v1.Speak(); t1.Speak(); } }