C#基础学习之练手

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

namespace  DerivedClass
{
     class  DataBase
    {
         public   int  common;

         public  DataBase()
        {
            common  =   100 ;
        }

         public   void  commonMethod()
        {
            Console.WriteLine( " 调用DataBase方法 " );
        }
    }

     class  SQLServer : DataBase
    {
         public   void  SpecificSQLServer()
        {
            Console.WriteLine( " 调用SQL Server方法 " );
        }
    }

     class  Oracle : DataBase
    {
         public   void  SpecificOracle()
        {
            Console.WriteLine( " 调用Oracle方法 " );
        }
    }

     class  Program
    {
         static   void  Main( string [] args)
        {
            Console.WriteLine( " 初始化SQL Server对象 " );
            SQLServer sqlserver  =   new  SQLServer();
            Console.WriteLine( " 调用SQL Server的方法SpecificSQLServer " );
            sqlserver.SpecificSQLServer();
            Console.WriteLine( " 调用SQL Server的方法commonMethod " );
            sqlserver.commonMethod();
            Console.WriteLine( " sqlserver.common.value = {0} " ,sqlserver.common);
        }
    }
}