C# 文法練習(10): 類[二] – 繼承、覆蓋、多態、隱藏

繼承:

using System;class Parent{    public void Msg() { Console.WriteLine("Parent"); }}class Child : Parent { }class Program{    static void Main()    {        Parent ObjParent = new Parent();        Child ObjChild = new Child();        ObjParent.Msg(); //Parent        ObjChild.Msg();  //Parent        Console.ReadKey();    }}

覆蓋:

using System;class Parent{    public virtual void Msg() { Console.WriteLine("Parent"); }}class Child : Parent {    public override void Msg() { Console.WriteLine("Child"); }}class Program{    static void Main()    {        Parent ObjParent = new Parent();        Child ObjChild = new Child();        ObjParent.Msg(); //Parent        ObjChild.Msg();  //Child        Console.ReadKey();    }}

多態:

using System;class Parent{    public virtual void Msg() { Console.WriteLine("Parent"); }}class Child1 : Parent {    public override void Msg() { Console.WriteLine("Child_1"); }}class Child2 : Parent{    public override void Msg() { Console.WriteLine("Child_2"); }}class Program{    static void Main()    {        Parent Obj1 = new Child1();        Parent Obj2 = new Child2();        Obj1.Msg(); //Child_1        Obj2.Msg(); //Child_2        Console.ReadKey();    }}

隱藏:

using System;class Parent{    public void Msg() { Console.WriteLine("Parent"); }}/* 有意隱藏應使用 new 關鍵字 */class Child1 : Parent {    new public void Msg() { Console.WriteLine("Child_1"); }}/* 無意隱藏會有提示, 但可用 */class Child2 : Parent{    public void Msg() { Console.WriteLine("Child_2"); }}class Program{    static void Main()    {        Parent Obj1 = new Child1();        Parent Obj2 = new Child2();        Child1 Obj3 = new Child1();        Child2 Obj4 = new Child2();        Obj1.Msg(); //Parent        Obj2.Msg(); //Parent        Obj3.Msg(); //Child_1        Obj4.Msg(); //Child_2        Console.ReadKey();    }}