AppDelegate.applicationDidBecomeActive在重新打开应用程序后会注意到。
let formatter = DateFormatter()
formatter.locale = NSLocale(localeIdentifier: "en_US_POSIX") as Locale!
//Specified date format
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss"
//Style can be medium, full and short as per the need.
formatter.dateStyle = .medium
let parsedDateString = formatter.date(from: stringDate)