swift时间戳和时间的转换

时间戳转成字符串

    //时间戳转成字符串
    func timeIntervalChangeToTimeStr(timeInterval:Double, _ dateFormat:String? = "yyyy-MM-dd HH:mm:ss") -> String {
        let date:NSDate = NSDate.init(timeIntervalSince1970: timeInterval)
        let formatter = DateFormatter.init()
        if dateFormat == nil {
            formatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
        }else{
            formatter.dateFormat = dateFormat
        }
        return formatter.string(from: date as Date)
    }

字符串转时间戳

 //MARK:- 字符串转时间戳
    func timeStrChangeTotimeInterval(_ dateFormat:String? = "yyyy-MM-dd HH:mm:ss") -> String {
        if self.isEmpty {
            return ""
        }
        let format = DateFormatter.init()
        format.dateStyle = .medium
        format.timeStyle = .short
        if dateFormat == nil {
            format.dateFormat = "yyyy-MM-dd HH:mm:ss"
        }else{
            format.dateFormat = dateFormat
        }
        let date = format.date(from: self)
        return String(date!.timeIntervalSince1970)
    }