[Design Patterns] 原型模式(Prototype)

型態：生成模式(CreationalPattern)。
定義：用原型實例指定建立物件的種類，並且透過拷貝這些原型建立新的物件。

結構圖：來源

原型模式其實就是從一個物件再建立另外一個可訂製的物件，而且不須知道任何建立的細節。
其中有區分為「淺複製」與「深複製」
淺複製：複製所有欄位，參考型別只複製參考。
深複製：建立新的物件。

先來看一下「淺複製」

Resume 類別 (履歷)

//簡歷類別，實作 ICloneable 介面 class Resume : ICloneable { private string name; private string sex; private string age; private WorkExperience work; public Resume(string name) { this.name = name; work = new WorkExperience(); } //設置個人資訊 public void SetPersonalInfo(string sex, string age) { this.sex = sex; this.age = age; } //設置工作經歷 public void SetWorkExperience(string workDate, string company) { work.WorkDate = workDate; work.Company = company; } //顯示 public void Display() { Console.WriteLine("{0} {1} {2}", name, sex, age); Console.WriteLine("工作經歷：{0} {1}", work.WorkDate, work.Company); } public Object Clone() { return (Object)this.MemberwiseClone(); } }

 

WorkExperience 類別 (工作經歷)

//工作經歷 類別 class WorkExperience { private string workDate; public string WorkDate { get { return workDate; } set { workDate = value; } } private string company; public string Company { get { return company; } set { company = value; } } }

 

前端調用

class Program { static void Main(string[] args) { Resume a = new Resume("大鳥"); a.SetPersonalInfo("男", "29"); a.SetWorkExperience("1998-2000", "XX公司"); Resume b = (Resume)a.Clone(); b.SetWorkExperience("1998-2006", "YY企業"); Resume c = (Resume)a.Clone(); c.SetPersonalInfo("男", "24"); c.SetWorkExperience("1998-2003", "ZZ企業"); a.Display(); b.Display(); c.Display(); Console.Read(); } }

 

輸出

上面例子，
我們希望顯示三個不同的工作經歷，可惜沒有達到。

所以我們這時候來借重「深複製」

WorkExperience 類別 (工作經歷)

//工作經歷 class WorkExperience : ICloneable { private string workDate; public string WorkDate { get { return workDate; } set { workDate = value; } } private string company; public string Company { get { return company; } set { company = value; } } public Object Clone() { return (Object)this.MemberwiseClone(); } }

 

Resume 類別 (履歷)

//簡歷 class Resume : ICloneable { private string name; private string sex; private string age; private WorkExperience work; public Resume(string name) { this.name = name; work = new WorkExperience(); } private Resume(WorkExperience work) { this.work = (WorkExperience)work.Clone(); } //設置個人資訊 public void SetPersonalInfo(string sex, string age) { this.sex = sex; this.age = age; } //設置工作經歷 public void SetWorkExperience(string workDate, string company) { work.WorkDate = workDate; work.Company = company; } //顯示 public void Display() { Console.WriteLine("{0} {1} {2}", name, sex, age); Console.WriteLine("工作經歷：{0} {1}", work.WorkDate, work.Company); } public Object Clone() { Resume obj = new Resume(this.work); obj.name = this.name; obj.sex = this.sex; obj.age = this.age; return obj; } }

前端調用

Program 類別

class Program { static void Main(string[] args) { Resume a = new Resume("大鳥"); a.SetPersonalInfo("男", "29"); a.SetWorkExperience("1998-2000", "XX公司"); Resume b = (Resume)a.Clone(); b.SetWorkExperience("1998-2006", "YY企業"); Resume c = (Resume)a.Clone(); c.SetWorkExperience("1998-2003", "ZZ企業"); a.Display(); b.Display(); c.Display(); Console.Read(); } }

輸出