userInfo对象UILocalNotification的符合性要求

Question

使用Swift-2.2，

我想将'struct‘或'class对象’传递给userInfo of UILocalNotification。(见代码-下图)。

您能告诉我如何修改这个结构才能符合UserInfo的要求吗？

我读到了一些关于

UserInfo不能是一个结构(但我也尝试过一个类--它也不起作用)

( b) "plist类型“符合->但我如何做到？

( c) "NSCoder“和"NSObject”的一致性--> --但我怎么做呢？

运行以下代码时收到的错误消息是：

“无法序列化userInfo”

谢谢你在这方面的帮助。

struct MeetingData {
    let title: String
    let uuid: String
    let startDate: NSDate
    let endDate: NSDate
}

let notification = UILocalNotification()
notification.category = "some_category"
notification.alertLaunchImage = "Logo"
notification.fireDate = NSDate(timeIntervalSinceNow: 10)
notification.alertBody = "Data-Collection Request!"
//        notification.alertAction = "I want to participate"
notification.soundName = UILocalNotificationDefaultSoundName

let myData = MeetingData(title: "myTitle",
                          uuid: "myUUID",
                     startDate: NSDate(),
                       endDate: NSDate(timeIntervalSinceNow: 10))

// that's where everything crashes !!!!!!!!!!!!!!
notification.userInfo = ["myKey": myData] as [String: AnyObject]

Answer 1

正如UILocalNotification.userInfo的文档所述：

您可以将任意的键值对添加到此字典中。但是，键和值必须是有效的属性-列表类型；如果没有，则引发异常。

您需要自己将数据转换为此类型。你可能想做这样的事情：

enum Keys {
    static let title = "title"
    static let uuid = "uuid"
    static let startDate = "startDate"
    static let endDate = "endDate"
}
extension MeetingData {
    func dictionaryRepresentation() -> NSDictionary {
        return [Keys.title: title,
                Keys.uuid: uuid,
                Keys.startDate: startDate,
                Keys.endDate: endDate]
    }
    init?(dictionaryRepresentation dict: NSDictionary) {
        if let title = dict[Keys.title] as? String,
            let uuid = dict[Keys.uuid] as? String,
            let startDate = dict[Keys.startDate] as? NSDate,
            let endDate = dict[Keys.endDate] as? NSDate
        {
            self.init(title: title, uuid: uuid, startDate: startDate, endDate: endDate)
        } else {
            return nil
        }
    }
}

然后可以使用myData.dictionaryRepresentation()转换为字典，使用MeetingData(dictionaryRepresentation: ...)从字典进行转换。