我是Swift和iOS的新手,在制作应用程序时遇到了这个问题。我想基本上使用NSCoding将用户数据存储到本地存储中。但是,我下面的代码没有做到这一点。谁能告诉我这是怎么回事?非常感激!
另外,在appDelegate的applicationDidEnterBackground和applicationWillTerminate下都调用saveChecklist和LoadChecklist。
我感觉我的问题出在encodeWithCoder和init(aDecoder)上,因为我使用GET将我的Checklist项目追加到列表中。
我在DataModel.class中的代码:
import Foundation
class DataModel: NSObject, NSCoding {
var checklist = Checklist()
var lists: [Checklist] {
get {
return [checklist]
}
set {
}
}
override init() {
super.init()
loadChecklist()
}
// MARK: - All the saving stuff
func encodeWithCoder(aCoder: NSCoder) {
aCoder.encodeObject(checklist, forKey: "Checklist")
}
required init?(coder aDecoder: NSCoder) {
checklist = aDecoder.decodeObjectForKey("Checklist") as! Checklist
}
func documentsDirectory() -> String {
let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
return paths[0]
}
func dataFilePath() -> String {
return (documentsDirectory() as NSString).stringByAppendingPathComponent("Checklist.plist") // create file if no checklist.plist is present
}
func saveChecklist() {
let data = NSMutableData()
let archiver = NSKeyedArchiver(forWritingWithMutableData: data)
archiver.encodeObject(lists, forKey: "Checklists")
archiver.finishEncoding()
data.writeToFile(dataFilePath(), atomically: true)
}
func loadChecklist() {
let path = dataFilePath()
if NSFileManager.defaultManager().fileExistsAtPath(path) {
if let data = NSData(contentsOfFile: path) {
let unarchiver = NSKeyedUnarchiver(forReadingWithData: data)
lists = unarchiver.decodeObjectForKey("Checklists") as! [Checklist]
unarchiver.finishDecoding()
}
}
}
我在Checklist.class中的代码:
import Foundation
class Checklist: NSObject, NSCoding {
var item = [items]()
var rituals = [items]()
var doneButtonVisible: Bool
var streak: Int
var itemDoneCount: Int
var startDate: NSDate
var dayHasStarted: Bool
override init() {
doneButtonVisible = false
itemDoneCount = 0
streak = 0
startDate = NSDate()
dayHasStarted = false
super.init()
}
// saves
func encodeWithCoder(aCoder: NSCoder) {
aCoder.encodeObject(item, forKey: "Items")
aCoder.encodeObject(rituals, forKey: "Rituals")
aCoder.encodeObject(itemDoneCount, forKey: "ItemDoneCount")
aCoder.encodeObject(doneButtonVisible, forKey: "DoneButtonVisible")
aCoder.encodeObject(streak, forKey: "Streak")
aCoder.encodeObject(startDate, forKey: "StartDate")
aCoder.encodeObject(dayHasStarted, forKey: "DayHasStarted")
}
// loads
required init?(coder aDecoder: NSCoder) {
item = aDecoder.decodeObjectForKey("Items") as! [items]
rituals = aDecoder.decodeObjectForKey("Rituals") as! [items]
itemDoneCount = aDecoder.decodeObjectForKey("ItemDoneCount") as! Int
doneButtonVisible = aDecoder.decodeObjectForKey("DoneButtonVisible") as! Bool
streak = aDecoder.decodeObjectForKey("Streak") as! Int
startDate = aDecoder.decodeObjectForKey("StartDate") as! NSDate
dayHasStarted = aDecoder.decodeObjectForKey("DayHasStarted") as! Bool
super.init()
}
}
更新
通过修改数据模型解决了保存和加载问题。改用Core Data保存和加载数据。
但是,我仍然不知道为什么上面的代码无法加载。显然,它不会保存清单的内容。
最佳答案
您的Checklist
类也需要继承自NSCoding,并实现encodeWithCoder(coder: NSCoder)
方法。 This是有关NSCoding的很好的教程。
关于ios - Swift,NSCoding保存类的数组不起作用,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/36867779/