public:公开的，共有的

private:私有的，只能在当前类的内部使用

Protected：受保护的，只能在当前类的内部以及该类的子类中使用

Internal:只能在当前程序集中访问

Protected internal:

 

1) 能够修饰类的访问修饰符只有两个：public和internal

2) 可访问性不一致

子类的访问权限不能高于父类，会暴露父类的成员

 

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 
 7 namespace _02访问修饰符
 8 {
 9     class Program
10     {
11         static void Main(string[] args)
12         {
13             Person p = new Person();
14         }
15     }
16 
17     public class Person
18     {
19         //protected string _name;
20         //public int _age;
21         //private char _gender;
22         //internal int _chinese;
23         //protected internal int _math;
24     }
25 
26     public class Student : Person
27     {
28 
29     }
30 
31     //public class Student:Person
32     //{
33 
34     //}
35 }

 

设计模式 设计这个项目的一种方式。

简单工厂设计模式

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 
 7 namespace _03简单工厂设计模式
 8 {
 9     class Program
10     {
11         static void Main(string[] args)
12         {
13             Console.WriteLine("请输入您想要的笔记本品牌");
14             string brand = Console.ReadLine();
15             NoteBook nb = GetNoteBook(brand);
16             nb.SayHello();
17             Console.ReadKey();
18         }
19 
20 
21         /// <summary>
22         /// 简单工厂的核心 根据用户的输入创建对象赋值给父类
23         /// </summary>
24         /// <param name="brand"></param>
25         /// <returns></returns>
26         public static NoteBook GetNoteBook(string brand)
27         {
28             NoteBook nb = null;
29             switch (brand)
30             {
31                 case "Lenovo": nb = new Lenovo();
32                     break;
33                 case "IBM": nb = new IBM();
34                     break;
35                 case "Acer": nb = new Acer();
36                     break;
37                 case "Dell": nb = new Dell();
38                     break;
39             }
40             return nb;
41         }
42     }
43 
44     public abstract class NoteBook
45     {
46         public abstract void SayHello();
47     }
48 
49     public class Lenovo : NoteBook
50     {
51         public override void SayHello()
52         {
53             Console.WriteLine("我是联想笔记本，你联想也别想");
54         }
55     }
56 
57 
58     public class Acer : NoteBook
59     {
60         public override void SayHello()
61         {
62             Console.WriteLine("我是鸿基笔记本");
63         }
64     }
65 
66     public class Dell : NoteBook
67     {
68         public override void SayHello()
69         {
70             Console.WriteLine("我是戴尔笔记本");
71         }
72     }
73 
74     public class IBM : NoteBook
75     {
76         public override void SayHello()
77         {
78             Console.WriteLine("我是IBM笔记本");
79         }
80     }
81 }