前言:使用自动归档我们需要遵守
NSCoding协议,但是通过一些Json转Model的工具来完成转Model后,比如遵守HandyJSON,再遵守NSCoding协议,会出现冲突Multiple inheritance from classes 'BaseModel' and 'NSCoder',这里暂时只用了HandyJSON来转Model,其他工具未知
import HandyJSON
// -MARK: 继承此model不用重写init()函数
class BaseModel: HandyJSON {
required init() {}
}
工具使用
var dic = [String: Any]()
dic["id"] = Int(tf_1.text!) // 因为模型指定的是Int 类型的 必须转成指定类型不然会失败
dic["name"] = tf_2.text
dic["age"] = Int(tf_3.text!)
dic["phone"] = tf_4.text
guard let json = dic.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)")
-
运行结果
-
存在问题
使用案例:在Model中id是Int类型,这里给的是String类型
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
报错:主要是Codable必须是指定类型的才能转换,不然会出现以下错误
typeMismatch(Swift.Int, Swift.DecodingError.Context(codingPath: [CodingKeys(stringValue: "id", intValue: nil)], debugDescription: "Expected to decode Int but found a string/data instead.", underlyingError: nil))
以下方法主要是利用Codable来完成Json转Model
- 自定义Error
enum HWMapError: Error {
case jsonToModelFail //json转model失败
case jsonToDataFail //json转data失败
}
- 定义
HWMappable协议继承Codable
public protocol HWMappable: Codable {
func hw_modelMapFinished()
mutating func hw_structMapFinished()
}
extension HWMappable {
public func hw_modelMapFinished() {
//外部自己实现
}
public mutating func hw_structMapFinished() {
//外部自己实现
}
///JSON转模型
static func hw_mapFromJson<T : HWMappable>(_ JSONString : String, _ type:T.Type) throws -> T {
guard let jsonData = JSONString.data(using: .utf8) else {
throw HWMapError.jsonToDataFail
}
let decoder = JSONDecoder()
do {
let obj = try decoder.decode(type, from: jsonData)
var vobj = obj
let mirro = Mirror(reflecting: vobj)
if mirro.displayStyle == Mirror.DisplayStyle.struct {
vobj.hw_structMapFinished()
}
if mirro.displayStyle == Mirror.DisplayStyle.class {
vobj.hw_modelMapFinished()
}
return vobj
} catch {
print(error)
}
throw HWMapError.jsonToModelFail
}
}
自动归档
@objcMembers class UserInfo: NSObject, NSCoding, HWMappable {
var id: Int = 0 // 用户id
var name: String = ""
var phone: String = ""
var age = 0
/// json转模型
class func jsonToUser(_ json:String) -> UserInfo? {
let user = try? UserInfo.hw_mapFromJson(json, UserInfo.self)
return user
}
// 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() {
guard let value = self.value(forKey: name) else {
return
}
aCoder.encode(value, forKey: name)
}
}
// MARK: - 解档
internal required init?(coder aDecoder: NSCoder){
super.init()
for name in getAllPropertys() {
guard let value = aDecoder.decodeObject(forKey: name) else {
return
}
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
}
}
使用工具
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("account.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.jsonToUser(json) else {
return
}
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
}else{
}
}
}
// 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
}
}
// MARK: - json转字典
extension String {
func hw_toDictionary() -> NSDictionary? {
guard let jsonData:Data = self.data(using: .utf8) else {
return nil
}
let dict = try? JSONSerialization.jsonObject(with: jsonData, options: .mutableContainers)
if dict != nil {
return dict as? NSDictionary
}
return nil
}
}
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