个回答

• Sneakerhead

  2017-12-30 16:21:16

  已采纳

  using System;
  using System.Collections.Generic;
  using System.Linq;
  using System.Text;
  using System.Threading.Tasks;
  
  namespace ConsoleApplication1
  {
      //public class Pet {
      //    public Pet(string name) {
      //        _name = name;
          
      //    }
      //    protected string _name;
      //    public void PrintName() {
  
      //        Console.WriteLine("Pet`s name is"+_name);  
      //    }
      //   //虚方法
      //    virtual public void speak() {
  
      //        Console.WriteLine(_name+"is speaking");
      //    }
      //}
      //结构
      struct fish {
          int weight;
          int price;
      
      }
      //接口
      interface ICatchMice {
  
          void catchMice();
      }
      interface IClimbTree {
  
          void climbTree();
      }
     abstract public class Pet
      {
          public Pet(string name)
          {
              _name = name;
  
          }
          protected string _name;
          public void PrintName()
          {
  
              Console.WriteLine("Pet`s name is" + _name);
          }
          //抽象类，没有函数体，无法实例化
          abstract public void speak();
          //{
  
              //Console.WriteLine(_name + "is speaking");
          //}
      }
      //狗类
      public class Dog : Pet {
          //静态
          static int num;
          static Dog() {
              num = 0;
          
          }
          //构造函数
          public Dog(string name):base(name) {
              //_name = name;
              ++num;
          
          }
          new public void PrintName() {
              Console.WriteLine("我的宠物是"+_name);
          }
          public override void speak()//重写
          {
              Console.WriteLine(_name + " is speaking"+" wow");
          }
          static public void ShowNum() {
  
              Console.WriteLine("有"+num+"条狗");
          }
      }
      //猫类
      public class Cat : Pet,ICatchMice,IClimbTree {
          //构造函数
          public Cat(string name):base(name) {
              //_name = name;
          
          }
          new public void PrintName() {
              Console.WriteLine("我的宠物是"+_name);
          }
          public override void speak()
          {
              Console.WriteLine(_name + "is speaking"+" meow");
          }
          public void catchMice() {
  
              Console.WriteLine("catchmice");
          }
          public void climbTree() {
              Console.WriteLine("climbtree");
          }
      
      }
      //静态类，方法扩展
      static class PetGuide{
  
          static public void HowToFeed(this Dog dog) {
              Console.WriteLine("Play a vedio how to feed dog");
          }
      
      }
      class Program
      {
          static void Main(string[] args)
          {
  
              //Dog Dog = new Dog();
              //Dog.Name = "Jack";
              //Dog.PrintName();
              //Dog.speak();
              //Pet Cat = new Cat();
              //Cat.Name = "Tom";
              //Cat.PrintName();
              //Cat.speak();
              Pet[] pets = new Pet[]{new Dog("Jack"),new Cat("Tom")};
              for (int i = 0; i < pets.Length;i++ ) {
                  pets[i].speak();
               
              }
              Cat c = new Cat("Tom2");
              IClimbTree climb = (IClimbTree)c;
              c.catchMice();
              climb.climbTree();
              Dog a = new Dog("Jack1");
              Dog.ShowNum();
  
              Dog dog = new Dog("Tommy");
              dog.HowToFeed();
  
  
  
          }
      }
  }
  
  

  3