本文是依赖HandyJSON转模型来实现归档
不需要依赖第三方可以看Swift-自动归档

测试代码

@IBAction func btnClick(_ sender: Any) {
        let dict = [
            "id" : 2,
            "name" : "隔壁老王",
            "age" : 31,
            "phone" : "110"
            ] as [String : Any]
        guard let json = dict.hw_toJSONString() else {
            print("出错")
            return
        }
        UserTool.saveUser(json) // 存
        guard let user = UserTool.getUser() else { // 取
            print("归档失败")
            return
        }
        print("id:\(user.id)\n名字:\(user.name)\n年龄:\(user.age)\n电话:\(user.phone)")
}

// MARK: - 字典转json
extension Dictionary {
    public func hw_toJSONString() -> String? {
        if (!JSONSerialization.isValidJSONObject(self)) {
            print("dict转json失败")
            return nil
        }
        if let newData : Data = try? JSONSerialization.data(withJSONObject: self, options: []) {
            let JSONString = NSString(data:newData as Data,encoding: String.Encoding.utf8.rawValue)
            return JSONString as String? ?? nil
        }
        print("dict转json失败")
        return nil
    }
}

输出内容

id:2
名字:隔壁老王
年龄:31
电话:110

代码实现(注:需依赖第三方HandyJSON)

import HandyJSON

// 在类名前面是使用objcMembers修饰，系统会在自动给这个类的所有方法添加@objc，暴露给OC。
@objcMembers class UserInfo: NSObject, HandyJSON, NSCoding {
    
    var id: Int = 0 // 用户id
    var name: String = ""
    var phone: String = ""
    var age = 0
    
    override required init() { super.init() }
    
    // MARK: - 归档
    func encode(with aCoder: NSCoder) {
        UserTool.removeUser() // 归档前先删除原来的 避免错误
        for name in getAllPropertys() {
            let value = self.value(forKey: name)
            if (value == nil) { continue }
            aCoder.encode(value, forKey: name)
        }
    }
    
    // MARK: - 解档
    internal required init?(coder aDecoder: NSCoder){
        super.init()
        for name in getAllPropertys() {
            let value = aDecoder.decodeObject(forKey: name)
            if (value == nil) { continue }
            setValue(value, forKeyPath: name)
        }
    }
    
    // MARK: - 获取属性数组
    func getAllPropertys() -> [String] {
        var count: UInt32 = 0 // 这个类型可以使用CUnsignedInt,对应Swift中的UInt32
        let properties = class_copyPropertyList(self.classForCoder, &count)
        var propertyNames: [String] = []
        for i in 0..<Int(count) { // Swift中类型是严格检查的，必须转换成同一类型
            if let property = properties?[i] { // UnsafeMutablePointer<objc_property_t>是可变指针，因此properties就是类似数组一样，可以通过下标获取
                let name = property_getName(property)
                // 这里还得转换成字符串
                let strName = String(cString: name)
                propertyNames.append(strName)
            }
        }
        // 不要忘记释放内存，否则C语言的指针很容易成野指针的
        free(properties)
        return propertyNames
    }
}

class UserTool {
    // MARK: - 归档路径设置
    static private var Path: String {
        let path = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).last!
        return (path as NSString).appendingPathComponent("\(self).plist")
    }

    /// 是否登录
    static func isLogin() -> Bool {
        guard UserTool.getUser() != nil else {return false} // 文件不存在
        return true
    }
    
    /// 存档
    static func saveUser(_ json: String) {
        guard let user = UserInfo.deserialize(from: json) else { return } // HandyJSON转模型
        NSKeyedArchiver.archiveRootObject(user, toFile: Path)
    }
    
    /// 获取用户信息
    static func getUser() -> UserInfo? {
        let user = NSKeyedUnarchiver.unarchiveObject(withFile: Path) as? UserInfo
        return user
    }
    
    /// 删档
    static func removeUser() {
        if FileManager.default.fileExists(atPath: Path) {
            try! FileManager.default.removeItem(atPath: Path) // 删除文件
        }
    }
}