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

以下是一个更结构化/灵活的方法:(Swift 3)

struct StopWatch {

    var totalSeconds: Int

    var years: Int {
        return totalSeconds / 31536000
    }

    var days: Int {
        return (totalSeconds % 31536000) / 86400
    }

    var hours: Int {
        return (totalSeconds % 86400) / 3600
    }

    var minutes: Int {
        return (totalSeconds % 3600) / 60
    }

    var seconds: Int {
        return totalSeconds % 60
    }

    //simplified to what OP wanted
    var hoursMinutesAndSeconds: (hours: Int, minutes: Int, seconds: Int) {
        return (hours, minutes, seconds)
    }
}

let watch = StopWatch(totalSeconds: 27005 + 31536000 + 86400)
print(watch.years) // Prints 1
print(watch.days) // Prints 1
print(watch.hours) // Prints 7
print(watch.minutes) // Prints 30
print(watch.seconds) // Prints 5
print(watch.hoursMinutesAndSeconds) // Prints (7, 30, 5)

使用这样的方法可以添加方便的解析，如下所示:

extension StopWatch {

    var simpleTimeString: String {
        let hoursText = timeText(from: hours)
        let minutesText = timeText(from: minutes)
        let secondsText = timeText(from: seconds)
        return "\(hoursText):\(minutesText):\(secondsText)"
    }

    private func timeText(from number: Int) -> String {
        return number < 10 ? "0\(number)" : "\(number)"
    }
}
print(watch.simpleTimeString) // Prints 07:30:05

值得注意的是，纯基于整数的方法不考虑闰日/秒。如果用例处理的是真实的日期/时间，则应该使用Date和Calendar。

我正在使用这个扩展

 extension Double {

    func stringFromInterval() -> String {

        let timeInterval = Int(self)

        let millisecondsInt = Int((self.truncatingRemainder(dividingBy: 1)) * 1000)
        let secondsInt = timeInterval % 60
        let minutesInt = (timeInterval / 60) % 60
        let hoursInt = (timeInterval / 3600) % 24
        let daysInt = timeInterval / 86400

        let milliseconds = "\(millisecondsInt)ms"
        let seconds = "\(secondsInt)s" + " " + milliseconds
        let minutes = "\(minutesInt)m" + " " + seconds
        let hours = "\(hoursInt)h" + " " + minutes
        let days = "\(daysInt)d" + " " + hours

        if daysInt          > 0 { return days }
        if hoursInt         > 0 { return hours }
        if minutesInt       > 0 { return minutes }
        if secondsInt       > 0 { return seconds }
        if millisecondsInt  > 0 { return milliseconds }
        return ""
    }
}

用途不同

// assume myTimeInterval = 96460.397    
myTimeInteval.stringFromInterval() // 1d 2h 47m 40s 397ms

最新代码:XCode 10.4 Swift 5

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

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

在macOS 10.10+ / iOS 8.0+ (NS)中，引入了DateComponentsFormatter来创建可读字符串。

它考虑用户的地区和语言。

let interval = 27005

let formatter = DateComponentsFormatter()
formatter.allowedUnits = [.hour, .minute, .second]
formatter.unitsStyle = .full

let formattedString = formatter.string(from: TimeInterval(interval))!
print(formattedString)

可用的单元样式有位置型、简写型、短型、全型、拼字型和简写型。

欲了解更多信息，请阅读文档。