C#入门(06): 访问权限

1.  private / Private – 只有在类内部是可见的

protected / Protected – 只有在类内部或派生类中是可见的

internal / Friend – 只有在同一个工程中/程序集中是可见的

protected internal / Protected Friend – 只有在类内部、相同的工程/程序集当中的类和派生类中是可见的

public / Public – 全局可见的

 

using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;

 namespace QuanXian
{

   public class Class1
    {
        private int i;
        internal int j;
        public int k;
        protected int l;
        protected internal int m;

        public void Test()
        {
            i = 1;
        }
    }

   public class Class2 : Class1
    {
        public Class2()
        {
        }
        public void TestMethod()
        {
            j = 3;
            k = 4;
            l = 5;
            m = 6;
            Class1 cd = new Class1();//jkm 说明对象不能访问私有和保护变量
 
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            Class1 cd = new Class1();//jkm
             cd.j = 1;
            cd.k = 1;
            cd.m = 1;
            //cd.l = 1;
 

            Class2 c2 = new Class2();//jkm
             c2.j = 1;
            c2.k = 1;
            c2.m = 1;
            //cd.l = 1;        
             
        }
    }
}
 

 

Protected 只对派生类可见。

 

另一个project想引用此project（QuanXian）

1：add ref

2：using QuanXian;

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using QuanXian;

namespace Project2
{

    class Class3 : Class1
    {
              
        public Class3()
        {
            //j = 3;
            k = 4;
            l = 5;
            m = 6;


            Class1 cd = new Class1();//jkm
            //cd.j = 1;
            cd.k = 1;
            //cd.m = 1;
            //cd.l = 1;

        }
        public void test2()
        {         

        }
    }


    class Program
    {


        static void Main(string[] args)
        {
        }
    }
}