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

在Swift 5中:

    var i = 9897

    func timeString(time: TimeInterval) -> String {
        let hour = Int(time) / 3600
        let minute = Int(time) / 60 % 60
        let second = Int(time) % 60

        // return formated string
        return String(format: "%02i:%02i:%02i", hour, minute, second)
    }

调用函数

    timeString(time: TimeInterval(i))

会在02:44:57返回

根据GoZoner的答案，我写了一个扩展，以获得时间格式化根据小时，分钟和秒:

extension Double {

    func secondsToHoursMinutesSeconds () -> (Int?, Int?, Int?) {
        let hrs = self / 3600
        let mins = (self.truncatingRemainder(dividingBy: 3600)) / 60
        let seconds = (self.truncatingRemainder(dividingBy:3600)).truncatingRemainder(dividingBy:60)
        return (Int(hrs) > 0 ? Int(hrs) : nil , Int(mins) > 0 ? Int(mins) : nil, Int(seconds) > 0 ? Int(seconds) : nil)
    }

    func printSecondsToHoursMinutesSeconds () -> String {

        let time = self.secondsToHoursMinutesSeconds()

        switch time {
        case (nil, let x? , let y?):
            return "\(x) min \(y) sec"
        case (nil, let x?, nil):
            return "\(x) min"
        case (let x?, nil, nil):
            return "\(x) hr"
        case (nil, nil, let x?):
            return "\(x) sec"
        case (let x?, nil, let z?):
            return "\(x) hr \(z) sec"
        case (let x?, let y?, nil):
            return "\(x) hr \(y) min"
        case (let x?, let y?, let z?):
            return "\(x) hr \(y) min \(z) sec"
        default:
            return "n/a"
        }
    }
}

let tmp = 3213123.printSecondsToHoursMinutesSeconds() // "892 hr 32 min 3 sec"

来自@Gamec的答案

typealias CallDuration = Int

extension CallDuration {
    func formatedString() -> String? {
        let hours = self / 3600
        let minutes = (self / 60) % 60
        let seconds = self % 60
        if hours > 0 { return String(format: "%0.2d:%0.2d:%0.2d", hours, minutes, seconds) }
        return String(format: "%0.2d:%0.2d", minutes, seconds)
    }
}

用法:

let duration: CallDuration = 3000
duration.formatedString() // 50 minute

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
    }
}

最新代码:XCode 10.4 Swift 5

extension Int {
    func timeDisplay() -> String {
        return "\(self / 3600):\((self % 3600) / 60):\((self % 3600) % 60)"
    }
}