【设计模式】原型模式

学习文章

• iOS设计模式 - 原型
• 获取对象类型

原理图

原型模式原理图.png

说明

• 原型模式指的是从一个已有的对象复制并创建出新的对象
• 当一个类的实例之间存在差异,而这些差异仅是状态的若干组合,复制原型要比手工实例化更加方便
• 当一个类并不容易创建(比如有着复杂的组合对象),且复制已有的组合对象要比对副本修改更加容易,此时,可以考虑使用原型模式

源码

实现复制的过程中,要考虑到变量是值类型,还是关系类型,才能准确复制.

对象要实现NSCopying协议,或者自己实现类似的复制协议(为了实现纯净的swift代码,而不是继承NSObject,就需要自己实现类似NSCopying的结构)

BaseCopyObject.swift

import UIKit

class BaseCopyObject: NSObject, NSCopying {
    
    required override init() {
        
    }
    
    /**
     实现NSCopying协议
     
     - parameter zone: zone description
     
     - returns: 新复制的对象
     */
    final func copyWithZone(zone : NSZone) -> AnyObject {
        
        // dynamicType用以获取动态类型
        let copy  = self.dynamicType.init()
        
        self.parametersCopyOperationWithBaseCopyObject(copy)
        
        return copy
    }
    
    /**
     参数复制操作,由子类重写
     
     - parameter object: 克隆体
     */
    func parametersCopyOperationWithBaseCopyObject(object : BaseCopyObject) {
    
    
    }
}  

Person.swift

import UIKit

class Person: BaseCopyObject {

    var personname : String?
    var age        : String?
    var dataArray  : [AnyObject]?
    var infoDic    : [String : AnyObject]?
    
    override func parametersCopyOperationWithBaseCopyObject(object: BaseCopyObject) {
        
        let personObject = object as! Person
        personObject.personname = self.personname
        personObject.age        = self.age
        personObject.dataArray  = self.dataArray
        personObject.infoDic    = self.infoDic
    }
}  

ViewController.swift

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        let personOne = Person()
        personOne.personname = "FrankLiu"
        personOne.age        = "26"
        personOne.dataArray  = ["1","2"]
        personOne.infoDic    = ["key1" : "value1","key2" : "value2"]
        
        print("person = \(personOne), name = \(personOne.personname),age = \(personOne.age),dataArray = \(personOne.dataArray),infoDic = \(personOne.infoDic)")
        
        let personTwo = personOne.copy()
        
        personOne.personname = "HaHa"
        personOne.age        = "28"
        personOne.dataArray  = ["3","4"]
        personOne.infoDic    = ["key3" : "value3","key4" : "value4"]
        
        print(personTwo,personTwo.personname,personTwo.age,personTwo.dataArray,personTwo.infoDic)
        print("person = \(personOne), name = \(personOne.personname),age = \(personOne.age),dataArray = \(personOne.dataArray),infoDic = \(personOne.infoDic)")
    }
}  

输出

person = <PrototypePattern.Person: 0x7ffb31736a10>, name = Optional("FrankLiu"),age = Optional("26"),dataArray = Optional([1, 2]),infoDic = Optional(["key1": value1, "key2": value2])
<PrototypePattern.Person: 0x7ffb31738ae0> Optional("FrankLiu") Optional("26") Optional([1, 2]) Optional(["key1": value1, "key2": value2])
person = <PrototypePattern.Person: 0x7ffb31736a10>, name = Optional("HaHa"),age = Optional("28"),dataArray = Optional([3, 4]),infoDic = Optional(["key4": value4, "key3": value3]  

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