.NET常用设计模式——工厂模式

工厂模式

存在一个创建对象的工厂
调用者从中取得特别的对象
由工厂决定如何符合调用需求
客户不知道对象如何生成

应用示列(一)



using System;

namespace CSDesingPattern

{

public enum UserType { Employee = 0, Sales = 1, Guest = 2 }

public class User

{

protected string mPermissionLevel = "Z";

public string GetPermissionLevel()

{

return mPermissionLevel;

}

}

public class Employee : User

{

public Employee()

{

mPermissionLevel = "A";

}

}

public class Sales : User

{

public Sales()

{

mPermissionLevel = "B";

}

}

public class Guest : User

{

public Guest()

{

mPermissionLevel = "C";

}

}

//工厂类

public class FactoryCreater

{

public FactoryCreater() { }

public static User CreateUser(UserType userType)

{

User u;

switch (userType)

{

case UserType.Employee:

u = new Employee();

break;

case UserType.Sales:

u = new Sales();

break;

case UserType.Guest:

u = new Guest();

break;

default:

u = new User();

break;

};

return u;

}

static void Main(string[] args)

{

Console.WriteLine("请输入使用者类型{0,1,2}");

UserType t = (UserType)int.Parse(Console.ReadLine());

User newUser = FactoryCreater.CreateUser(t);

Console.WriteLine("建立了{0}对象", newUser.ToString());

Console.WriteLine("权限等级={0}", newUser.GetPermissionLevel());

}

}

}

应用示例(二)



using System;

namespace NameFactory

{

//名字工厂类

public class NameFactory

{

public NameFactory() { }

public Namer getName(string name)

{

int i = name.IndexOf(",");

if (i > 0)

return new LastFirst(name);

else

return new FirstFirst(name);

}

}

public class Namer

{

//parts stored here

protected string frName, lName;

//return first name

public string getFrname()

{

return frName;

}

//return last name

public string getLname()

{

return lName;

}

}

public class FirstFirst : Namer

{

public FirstFirst(string name)

{

int i = name.IndexOf(" ");

if (i > 0)

{

frName = name.Substring(0, i).Trim();

lName = name.Substring(i + 1).Trim();

}

else

{

lName = name;

frName = "";

}

}

}

public class LastFirst : Namer

{

public LastFirst(string name)

{

int i = name.IndexOf(",");

if (i > 0)

{

lName = name.Substring(0, i);

frName = name.Substring(i + 1).Trim();

}

else

{

lName = name;

frName = "";

}

}

}

}