我有个奇怪的问题。我将自定义类对象保存在NSUserDefaults中,并且在检索对象的nil变量的数据时得到int。下面是自定义类

class User {
    var name: String?
    var user_id: Int?
    var account_id: Int?
    var location: String?
}

我把它保存为,
let defaults = NSUserDefaults.standardUserDefaults()
var data = NSKeyedArchiver.archivedDataWithRootObject([user]) // I can see the int values for the user objects here
defaults.setObject(data, forKey: "all_users")

检索数据为,
let defaults = NSUserDefaults.standardUserDefaults()

let data = defaults.dataForKey("all_users")
var users = [Users]()
if data != nil {
    let userData = NSKeyedUnarchiver.unarchiveObjectWithData(data!) as! [Users]

    for usr in userData {
        print("\(usr.name!)") // Prints the name
        print("\(usr.user_id!)") // Nil value here
        users.append(usr)
    }
}

我完全不知道这种行为的原因。

最佳答案

没有属性列表项的自定义类需要符合NSCoding才能保存在NSUserDefaults中。
以下是符合NSCoding的指南:http://nshipster.com/nscoding/
您需要这两个功能:

init(coder decoder: NSCoder) {
    self.name = decoder.decodeObjectForKey("name") as String
    self.user_id = decoder.decodeIntegerForKey("user_id")
    self.account_id = decoder.decodeIntegerForKey("account_id")
    self.location = decoder.decodeObjectForKey("self.location") as String

}

func encodeWithCoder(coder: NSCoder) {
    coder.encodeObject(self.name, forKey: "name")
    coder.encodeInt(self.user_id, forKey: "user_id")
    coder.encodeInt(account_id, forKey: "account_id")
    coder.encodeObject(self.location, forKey: "location")

}

关于ios - iOS:自定义对象的int变量在NSUserDefaults中返回nil,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/38513791/

10-12 14:44
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