Swift3 根据秒数获取视频时长（转换成00:00:00时间格式）以及将时长转换成秒

直接代码了：

 /// 秒转换成00:00:00格式
    ///
    /// - Parameter secounds: <#secounds description#>
    /// - Returns: <#return value description#>
    class func getFormatPlayTime(secounds:TimeInterval)->String{
        if secounds.isNaN{
            return "00:00"
        }
        var Min = Int(secounds / 60)
        let Sec = Int(secounds.truncatingRemainder(dividingBy: 60))
        var Hour = 0
        if Min>=60 {
            Hour = Int(Min / 60)
            Min = Min - Hour*60
            return String(format: "%02d:%02d:%02d", Hour, Min, Sec)
        }
        return String(format: "00:%02d:%02d", Min, Sec)
    }
    
    
    /// 根据00:00:00时间格式，转换成秒
    ///
    /// - Parameter str: <#str description#>
    /// - Returns: <#return value description#>
    class func getSecondsFromTimeStr(timeStr:String) -> Int {
        if timeStr.isEmpty {
            return 0
        }
        
        let timeArry = timeStr.replacingOccurrences(of: "：", with: ":").components(separatedBy: ":")
        var seconds:Int = 0
        
        if timeArry.count > 0 && isPurnInt(string: timeArry[0]){
            let hh = Int(timeArry[0])
            if hh! > 0 {
                seconds += hh!*60*60
            }
        }
        if timeArry.count > 1 && isPurnInt(string: timeArry[1]){
            let mm = Int(timeArry[1])
            if mm! > 0 {
                seconds += mm!*60
            }
        }
        
        if timeArry.count > 2 && isPurnInt(string: timeArry[2]){
            let ss = Int(timeArry[2])
            if ss! > 0 {
                seconds += ss!
            }
        }
        
        return seconds
        
    }

比如：

100s   -> 01:40

01:40  -> 100s 

enjoy～