使用 NSKeyedArchiver 和 Userdefault 保存结构数组,其中对象符合 NSCoding
Saving Array of Struct with NSKeyedArchiver and Userdefault in which object conform to NSCoding
作为面向协议的编程概念,我使用 Struct 创建了我的模型。
我想将“Struct
”的 数组 保存到 Userdefault 中。但是我在这个模型的数组 encode/decode 中遇到了问题。
这是我的模型结构
struct Room {
let name : String
let id : String
let booked : Bool
}
这里我创建了一个扩展这样
extension Room {
func decode() -> Room? {
let userClassObject = NSKeyedUnarchiver.unarchiveObject(withFile: RoomClass.path()) as? RoomClass
return userClassObject?.room
}
func encode() {
let personClassObject = RoomClass(room: self)
NSKeyedArchiver.archiveRootObject(personClassObject, toFile: RoomClass.path())
}
class RoomClass: NSObject, NSCoding {
var room : Room?
init(room: Room) {
self.room = room
super.init()
}
class func path() -> String {
let documentsPath = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.documentDirectory, FileManager.SearchPathDomainMask.userDomainMask, true).first
let path = documentsPath?.appending(("/Room"))
return path!
}
func encode(with aCoder: NSCoder) {
aCoder.encode(room!.name, forKey: "name")
aCoder.encode(room!.id, forKey: "Id")
aCoder.encode(room!.booked, forKey: "booked")
}
required init?(coder aDecoder: NSCoder) {
let _name = aDecoder.decodeObject(forKey: "name") as? String
let _id = aDecoder.decodeObject(forKey: "Id") as? String
let _booked = aDecoder.decodeBool(forKey: "booked")
room = Room(name: _name!, id: _id!, booked: _booked)
super.init()
}
}
}
当我尝试像这样保存 arrRoomList(房间对象数组)时
self.saveRooms(arrayRooms: arrRoomList)
我遇到了这个错误
[_SwiftValue encodeWithCoder:]: unrecognized selector sent to instance
我也尝试过先对每个对象进行编码,然后尝试将它们默认保存,然后也报错。
任何人都可以指导我如何以正确的方式 encode/decode Userdefaults 中的结构数组而不将其转换为字典吗?
你可以尝试像这样的模型
class CardModel: NSObject
{
let name : String
let id : String
let booked : Bool
override init()
{
self.name = ""
self.id = ""
self.booked = false
}
required init(coder aDecoder: NSCoder)
{
self.name = aDecoder.decodeObject(forKey: "name") as! String
self.id = aDecoder.decodeObject(forKey: "id") as! String
self.booked = aDecoder.decodeObject(forKey: "booked") as! Bool
}
func encodeWithCoder(_ aCoder: NSCoder)
{
aCoder.encode(name, forKey: "name")
aCoder.encode(id, forKey: "id")
aCoder.encode(booked, forKey: "booked")
}
}
通过创建 CardModel 模型对象使用
let objCardModel = CardModel()
objCardModel.name = "Shrikant"
objCardModel.id = "8"
objCardModel.booked = true
按对象访问
let userName = objCardModel.name
您可以像这样设置结构以直接使用 NSKeyedArchiver
:
struct Room {
let name : String
let id : String
let booked : Bool
}
extension Room {
func encode() -> Data {
let data = NSMutableData()
let archiver = NSKeyedArchiver(forWritingWith: data)
archiver.encode(name, forKey: "name")
archiver.encode(id, forKey: "id")
archiver.encode(booked, forKey: "booked")
archiver.finishEncoding()
return data as Data
}
init?(data: Data) {
let unarchiver = NSKeyedUnarchiver(forReadingWith: data)
defer {
unarchiver.finishDecoding()
}
guard let name = unarchiver.decodeObject(forKey: "name") as? String else { return nil }
guard let id = unarchiver.decodeObject(forKey: "id") as? String else { return nil }
booked = unarchiver.decodeBool(forKey: "booked")
self.name = name
self.id = id
}
}
要与 UserDefaults 一起使用,请这样调用:
// to encode to data and save to user defaults
let room = Room(name: "asdf", id: "123", booked: true)
UserDefaults.standard.set(room.encode(), forKey: "room")
// to retrieve from user defaults
if let data = UserDefaults.standard.object(forKey: "room") as? Data {
let room = Room(data: data)
}
可以save/retrieve一组像这样的房间:
func saveRooms(arrayRooms: [Room]) {
let roomsData = arrayRooms.map { [=12=].encode() }
UserDefaults.standard.set(roomsData, forKey: "rooms")
}
func getRooms() -> [Room]? {
guard let roomsData = UserDefaults.standard.object(forKey: "rooms") as? [Data] else { return nil }
return roomsData.flatMap { return Room(data: [=12=]) }
}
// save 2 rooms to user defaults
let roomA = Room(name: "A", id: "123", booked: true)
let roomB = Room(name: "B", id: "asdf", booked: false)
saveRooms(arrayRooms: [roomA, roomB])
// get the rooms
print(getRooms())
作为面向协议的编程概念,我使用 Struct 创建了我的模型。
我想将“Struct
”的 数组 保存到 Userdefault 中。但是我在这个模型的数组 encode/decode 中遇到了问题。
这是我的模型结构
struct Room {
let name : String
let id : String
let booked : Bool
}
这里我创建了一个扩展这样
extension Room {
func decode() -> Room? {
let userClassObject = NSKeyedUnarchiver.unarchiveObject(withFile: RoomClass.path()) as? RoomClass
return userClassObject?.room
}
func encode() {
let personClassObject = RoomClass(room: self)
NSKeyedArchiver.archiveRootObject(personClassObject, toFile: RoomClass.path())
}
class RoomClass: NSObject, NSCoding {
var room : Room?
init(room: Room) {
self.room = room
super.init()
}
class func path() -> String {
let documentsPath = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.documentDirectory, FileManager.SearchPathDomainMask.userDomainMask, true).first
let path = documentsPath?.appending(("/Room"))
return path!
}
func encode(with aCoder: NSCoder) {
aCoder.encode(room!.name, forKey: "name")
aCoder.encode(room!.id, forKey: "Id")
aCoder.encode(room!.booked, forKey: "booked")
}
required init?(coder aDecoder: NSCoder) {
let _name = aDecoder.decodeObject(forKey: "name") as? String
let _id = aDecoder.decodeObject(forKey: "Id") as? String
let _booked = aDecoder.decodeBool(forKey: "booked")
room = Room(name: _name!, id: _id!, booked: _booked)
super.init()
}
}
}
当我尝试像这样保存 arrRoomList(房间对象数组)时
self.saveRooms(arrayRooms: arrRoomList)
我遇到了这个错误
[_SwiftValue encodeWithCoder:]: unrecognized selector sent to instance
我也尝试过先对每个对象进行编码,然后尝试将它们默认保存,然后也报错。
任何人都可以指导我如何以正确的方式 encode/decode Userdefaults 中的结构数组而不将其转换为字典吗?
你可以尝试像这样的模型
class CardModel: NSObject
{
let name : String
let id : String
let booked : Bool
override init()
{
self.name = ""
self.id = ""
self.booked = false
}
required init(coder aDecoder: NSCoder)
{
self.name = aDecoder.decodeObject(forKey: "name") as! String
self.id = aDecoder.decodeObject(forKey: "id") as! String
self.booked = aDecoder.decodeObject(forKey: "booked") as! Bool
}
func encodeWithCoder(_ aCoder: NSCoder)
{
aCoder.encode(name, forKey: "name")
aCoder.encode(id, forKey: "id")
aCoder.encode(booked, forKey: "booked")
}
}
通过创建 CardModel 模型对象使用
let objCardModel = CardModel()
objCardModel.name = "Shrikant"
objCardModel.id = "8"
objCardModel.booked = true
按对象访问
let userName = objCardModel.name
您可以像这样设置结构以直接使用 NSKeyedArchiver
:
struct Room {
let name : String
let id : String
let booked : Bool
}
extension Room {
func encode() -> Data {
let data = NSMutableData()
let archiver = NSKeyedArchiver(forWritingWith: data)
archiver.encode(name, forKey: "name")
archiver.encode(id, forKey: "id")
archiver.encode(booked, forKey: "booked")
archiver.finishEncoding()
return data as Data
}
init?(data: Data) {
let unarchiver = NSKeyedUnarchiver(forReadingWith: data)
defer {
unarchiver.finishDecoding()
}
guard let name = unarchiver.decodeObject(forKey: "name") as? String else { return nil }
guard let id = unarchiver.decodeObject(forKey: "id") as? String else { return nil }
booked = unarchiver.decodeBool(forKey: "booked")
self.name = name
self.id = id
}
}
要与 UserDefaults 一起使用,请这样调用:
// to encode to data and save to user defaults
let room = Room(name: "asdf", id: "123", booked: true)
UserDefaults.standard.set(room.encode(), forKey: "room")
// to retrieve from user defaults
if let data = UserDefaults.standard.object(forKey: "room") as? Data {
let room = Room(data: data)
}
可以save/retrieve一组像这样的房间:
func saveRooms(arrayRooms: [Room]) {
let roomsData = arrayRooms.map { [=12=].encode() }
UserDefaults.standard.set(roomsData, forKey: "rooms")
}
func getRooms() -> [Room]? {
guard let roomsData = UserDefaults.standard.object(forKey: "rooms") as? [Data] else { return nil }
return roomsData.flatMap { return Room(data: [=12=]) }
}
// save 2 rooms to user defaults
let roomA = Room(name: "A", id: "123", booked: true)
let roomB = Room(name: "B", id: "asdf", booked: false)
saveRooms(arrayRooms: [roomA, roomB])
// get the rooms
print(getRooms())