使用runtime进行解档和归档

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首先我们先看一下不用runtime的写法，大家可能感觉很简单为什么要用runtime来实现，但是试想一下如果一个对象有很多很多的属性，我们还要一行一行写吗，和从json中给模型赋值一个道理

传统写法

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// 归档
func encodeWithCoder(aCoder: NSCoder) {
    aCoder.encodeObject(name, forKey: "name")
    aCoder.encodeObject(age, forKey: "age")
}
// 解档
required init?(coder aDecoder: NSCoder) {
    super.init()
    name = aDecoder.decodeObjectForKey("name") as? String
    age = aDecoder.decodeObjectForKey("age") as? Int
}

通用写法

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class Model: NSObject, NSCoding {
    dynamic var name = ""
    dynamic var age = 0
    override init() {
    }
    // 归档
    func encode(with aCoder: NSCoder) {
        var count: UInt32 = 0
        guard let ivars = class_copyIvarList(self.classForCoder, &count) else {
            return
        }
        for i in 0 ..< count {
            let ivar = ivars[Int(i)]
            let name = ivar_getName(ivar)
            
            let key = NSString.init(utf8String: name!) as! String
            
            if let value = self.value(forKey: key) {
                aCoder.encode(value, forKey: key)
            }
        }
        free(ivars)
    }
    // 解档
    required init?(coder aDecoder: NSCoder) {
        super.init()
        var count: UInt32 = 0
        guard let ivars = class_copyIvarList(self.classForCoder, &count) else {
            return
        }
        for i in 0 ..< count {
            let ivar = ivars[Int(i)]
            let name = ivar_getName(ivar)
            let key = NSString.init(utf8String: name!) as! String
            if let value = aDecoder.decodeObject(forKey: key) {
                self.setValue(value, forKey: key)
            }
        }
        free(ivars)
    }
}

  • 使用runtime解档归档的时候一定要在属性前加上dynamic 关键字,并且不能使用可选属性*

######下面我们准备一下要归档的模型和文件路径

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let model = Model()
model.name = "FlyChang"
model.age = 25
var path = NSSearchPathForDirectoriesInDomains(.cachesDirectory, .userDomainMask, true).last
path = path! + "/Model"

归档

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let data = NSMutableData()
let archiver = NSKeyedArchiver(forWritingWith: data)
archiver.encode(model, forKey: "model")
archiver.finishEncoding()
data.write(toFile: path!, atomically: true)

解档

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let data = NSData(contentsOfFile: path!)
let unarchiver = NSKeyedUnarchiver(forReadingWith: data)
let model = unarchiver.decodeObject(forKey: "model") as! Model
unarchiver.finishDecoding()

总结了一下使用runtime归档解档的方法，希望能给大家带来帮助~