C# 抽象类,抽象属性,抽象方法(实例讲解)

public abstract class Fruit
  {
    public string vendor { get; set; } //默认为private
    
    public abstract float Price { get; } //抽象属性必须是公有的
    public abstract void GrowInArea(); //抽象方法必须是公有的
  }

public class Apple : Fruit
  {
    public override float Price
    {
      get
      {
        if (vendor == "红富士")
          return 100;
        else
          return 0;
      }
    }
    public override void GrowInArea()
    {
      Console.WriteLine("我在南方北方都能生长,我的生产商是:" + vendor + ",我现在的价格是：" + Price);
    }
  }

public class Orange : Fruit
  {
    public override float Price
    {
      get
      {
        return 0;
      }
    }
    public override void GrowInArea()
    {
      Console.WriteLine("我只能生长在南方,我的生产商是:" + vendor + ",我的价格是：" + Price);
    }
  }

static void Main(string[] args)
    {
      Fruit f = new Apple();
      f.vendor = "红富士";
      f.GrowInArea();
      f = new Orange();
      f.vendor = "柑橘";
      f.GrowInArea();
      Console.ReadKey();
    }