Neek的答案不正确。

这是正确的版本

func seconds2Timestamp(intSeconds:Int)->String {
   let mins:Int = (intSeconds/60)%60
   let hours:Int = intSeconds/3600
   let secs:Int = intSeconds%60

   let strTimestamp:String = ((hours<10) ? "0" : "") + String(hours) + ":" + ((mins<10) ? "0" : "") + String(mins) + ":" + ((secs<10) ? "0" : "") + String(secs)
   return strTimestamp
}

SWIFT 3.0方案基本基于上述方案，并进行了扩展。

extension CMTime {
  var durationText:String {
    let totalSeconds = CMTimeGetSeconds(self)
    let hours:Int = Int(totalSeconds.truncatingRemainder(dividingBy: 86400) / 3600)
    let minutes:Int = Int(totalSeconds.truncatingRemainder(dividingBy: 3600) / 60)
    let seconds:Int = Int(totalSeconds.truncatingRemainder(dividingBy: 60))

    if hours > 0 {
        return String(format: "%i:%02i:%02i", hours, minutes, seconds)
    } else {
        return String(format: "%02i:%02i", minutes, seconds)
    }

  }
}

用AVPlayer这样调用它?

 let dTotalSeconds = self.player.currentTime()
 playingCurrentTime = dTotalSeconds.durationText

另一种方法是将秒转换为日期，并从日期本身取秒、分和小时。 此解决方案仅限于23:59:59

我已经构建了一个现有答案的mashup，以简化一切并减少Swift 3所需的代码量。

func hmsFrom(seconds: Int, completion: @escaping (_ hours: Int, _ minutes: Int, _ seconds: Int)->()) {

        completion(seconds / 3600, (seconds % 3600) / 60, (seconds % 3600) % 60)

}

func getStringFrom(seconds: Int) -> String {

    return seconds < 10 ? "0\(seconds)" : "\(seconds)"
}

用法:

var seconds: Int = 100

hmsFrom(seconds: seconds) { hours, minutes, seconds in

    let hours = getStringFrom(seconds: hours)
    let minutes = getStringFrom(seconds: minutes)
    let seconds = getStringFrom(seconds: seconds)

    print("\(hours):\(minutes):\(seconds)")                
}

打印:

00:01:40

@r3dm4n的回答很棒。然而，我也需要一个小时。以防别人也需要，这里是:

func formatSecondsToString(_ seconds: TimeInterval) -> String {
    if seconds.isNaN {
        return "00:00:00"
    }
    let sec = Int(seconds.truncatingRemainder(dividingBy: 60))
    let min = Int(seconds.truncatingRemainder(dividingBy: 3600) / 60)
    let hour = Int(seconds / 3600)
    return String(format: "%02d:%02d:%02d", hour, min, sec)
}

NSTimeInterval是Double，使用扩展。例子:

extension Double {

    var formattedTime: String {

        var formattedTime = "0:00"

        if self > 0 {

            let hours = Int(self / 3600)
            let minutes = Int(truncatingRemainder(dividingBy: 3600) / 60)

            formattedTime = String(hours) + ":" + (minutes < 10 ? "0" + String(minutes) : String(minutes))
        }

        return formattedTime
    }
}