内部类继承例子1 
 namespace GameStatistical.Test.InnerClass 
 { 
     public class Person 
     { 
         public class Student 
         { 
             public static int age; 
             internal static int height; 
             private static string sex; 

             public virtual void Show() 
             { 
                 Console.WriteLine("年龄:"+age); 
                 Console.WriteLine("身高:"+height); 
             } 

             internal void Display() 
             { 
                 Console.WriteLine("internal"); 
                 Console.WriteLine("年龄:" + age); 
                 Console.WriteLine("身高:" + height); 
             } 
         } 

         public void Show() 
         { 
             Student.age = 21; 
             Student.height = 75; 
             Student student = new Student(); 
             student.Show(); 
             student.Display(); 
         } 
     } 
 }