設計模式－簡單工廠模式（SimpleFactory-C#)

《Java與模式》 

上面那本書上的例子舉的是園丁和果園的例子，學習設計模式最好在生活中自己找個例子 

實踐一下，下面是我自己的一個例子，是講快餐店的例子，快餐店提供很多食物，比如 

面條，米飯，面包。首先定義了一個Food接口，然後這些食物都從它來繼承，定義了一個大廚 

他包辦所有食物的制作工作，這就是我所理解的簡單工廠模式的概念，下面是源代碼： 



using System; 


namespace SimpleFactoryPattern 
{ 
/// <summary> 
/// 簡單工廠模式示例 
/// </summary> 
class SimpleFactoryPattern 
{ 
//定義Food接口 
public interface Food 
{ 
//烹饪 
void Cook(); 
//賣出 
void Sell(); 

} 

//Noodle 

public class Noodle:Food 
{ 
public Noodle() 
{ 
Console.WriteLine("\nThe Noodle is made.."); 
} 
private int price; 

//面條Noodle的Cook方法接口實現 
public void Cook() 
{ 
Console.WriteLine("\nNoodle is cooking..."); 
} 

//面條Noodle的Sell方法接口實現 
public void Sell() 
{ 
Console.WriteLine("\nNoodle has been sold..."); 
} 
public int Price 
{ 
get{return this.price;} 
set{price=value;} 
} 
} 

//Rice 
public class Rice:Food 
{ 
public Rice() 
{ 
Console.WriteLine("\nThe Rice is made .."); 
} 
private int price; 
public void Cook() 
{ 
Console.WriteLine("\nRice is cooking..."); 
} 
public void Sell() 
{ 
Console.WriteLine("\nRice has been sold..."); 
} 
public int Price 
{ 
get{return this.price;} 
set{price=value;} 
} 
} 



//Bread 
public class Bread:Food 
{ 
public Bread() 
{ 
Console.WriteLine("\nThe Bread is made...."); 
}

private int price; 
public void Cook() 
{ 
Console.WriteLine("\nBread is cooking..."); 
} 
public void Sell() 
{ 
Console.WriteLine("\nBread has been sold..."); 
} 
public int Price 
{ 
get{return this.price;} 
set{price=value;} 
} 
} 


//定義大廚，他包辦這個快餐店裡的所有Food,包括面條，面包和米飯 
class Chef 
{ 
public static Food MakeFood(string foodName) 
{ 
try 
{ 
switch(foodName) 
{ 
case "noodle": return new Noodle(); 
case "rice":return new Rice(); 
case "bread":return new Bread(); 
default:throw new BadFoodException("Bad food request!"); 
} 
} 
catch(BadFoodException e) 
{ 
throw e; 
} 
} 

} 

//異常類，該餐館沒有的食品 
class BadFoodException: System.Exception 
{ 
public BadFoodException(string strMsg) 
{ 
Console.WriteLine(strMsg); 
} 
} 


/// <summary> 
/// 應用程序的主入口點。 
/// </summary> 
[STAThread] 
static void Main(string[] args) 
{ 
Food food=Chef.MakeFood("bread"); 
food.Cook(); 
food.Sell(); 
Console.ReadLine(); 
} 
} 
}