距离斯威夫特出生的天/小时/月/分钟

Question

我在将一些代码从 Objective-C 转换为 Swift 时遇到了一些问题。我正在尝试制作一个标签来说明我的年龄。我想给出我的生日，它会返回几天、几小时、几分钟、几秒关于我已经活了多久。代码是：

@IBAction func birthday(sender:AnyObject){

    var dateComponents = NSDateComponents()
    dateComponents.day = 19
    dateComponents.month = 12
    dateComponents.year = 1999

    var calender = NSCalendar(identifier: NSGregorianCalendar)
    var birthDate = calender!.dateFromComponents(dateComponents)
    var currentDate = NSDate.date()

    var durationDateComponents = calender.components(NSCalenderUnit.CalenderUnitDay, fromDate: birthDate!,
        toDate: currentDate,
        options: nil)

    var numberOfDaysFromBirth = durationDateComponents.day

    messageLabel.text = "\(numberOfDaysFromBirth)"
}

Answer 1

var dateComponents = NSDateComponents()
dateComponents.day = 19
dateComponents.month = 12
dateComponents.year = 1999

let birthDate = NSCalendar(identifier: NSGregorianCalendar)!.dateFromComponents(dateComponents)!

let durationDateComponents = NSCalendar(identifier: NSGregorianCalendar)!.components( .CalendarUnitYear | .CalendarUnitMonth | .CalendarUnitDay | .CalendarUnitHour |  .CalendarUnitMinute | .CalendarUnitSecond, fromDate: birthDate, toDate: NSDate(), options: nil)

let numberOfyearsFromBirth = durationDateComponents.year      // 15
let numberOfMonthsFromBirth = durationDateComponents.month    // 3
let numberOfDaysFromBirth = durationDateComponents.day        // 17
let numberOfHoursFromBirth = durationDateComponents.hour      // 1
let numberOfminutesFromBirth = durationDateComponents.minute  // 28
let numberOfsecondsFromBirth = durationDateComponents.second  // 34