扩：new and override

昨天有个网友问我继承里面的new和override关键词有啥区别，呃，我们来看个例子就知道了

new ==》隐藏父类同名方法  override==》覆盖

定义一个父类：

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public class People {     /// <summary>     ///ushort参考： https://msdn.microsoft.com/zh-CN/library/cbf1574z.aspx     /// </summary>     public string Name { get; set; }     public ushort Age { get; set; }       public People(string name, ushort age)     {         this.Name = name;         this.Age = age;     }     public void Hi()//People     {         Console.WriteLine("Name: " + this.Name + " Age: " + this.Age);     }     public virtual void Show()//People     {         Console.WriteLine("Name: " + this.Name + " Age: " + this.Age);     } }

　　定义一个子类:

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public class Student : People {     #region 属性     /// <summary>     /// 学校     /// </summary>     public string School { get; set; }     /// <summary>     /// 班级     /// </summary>     public string StrClass { get; set; }     /// <summary>     /// 学号     /// </summary>     public string StrNum { get; set; }     #endregion       #region 构造函数     /// <summary>     /// 调用父类构造函数     /// </summary>     /// <param name="name"></param>     /// <param name="age"></param>     public Student(string name, ushort age) : base(name, age)     {       }     public Student(string name, ushort age, string school, string strClass, string strNum) : this(name, age)     {         this.School = school;         this.StrClass = strClass;         this.StrNum = strNum;     }     #endregion       /// <summary>     /// new-隐藏     /// </summary>     public new void Hi()//Student     {         Console.WriteLine("Name: " + this.Name + " Age: " + this.Age + " School: " + this.School + " strClass: " + this.StrClass + " strNum: " + this.StrNum);     }     /// <summary>     /// override-覆盖     /// </summary>     public override void Show()//Student     {         Console.WriteLine("Name: " + this.Name + " Age: " + this.Age + " School: " + this.School + " strClass: " + this.StrClass + " strNum: " + this.StrNum);     } }

　　调用一下

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static void Main(string[] args)         {             People p = new Student("app", 10, "北京大学", "001", "01001");             p.Hi(); p.Show();               System.Console.WriteLine();               Student s = p as Student;             s.Hi(); s.Show();               System.Console.ReadKey();         }

　　输出：

可以发现，用new修饰的方法，其父方法并没有被改变，只是被隐藏了

用override重写的方法却被覆盖，从而改变了（多态）