//获取当前距1970时间戳
    func getNowTimestamp() -> Int{
        
        let date = NSDate.init()
        return Int(date.timeIntervalSince1970)
        
    }
 
    /*
     *获取指定距1970时间戳
      格式: "yyyy-MM-dd HH:mm:ss"
    */
    func getOtherTimestamp(timesDateString:String) ->Int{
        let df = DateFormatter.init()
        df.dateFormat = "yyyy-MM-dd HH:mm:ss"
        let ds = df.date(from: timesDateString)
        
        return Int((ds?.timeIntervalSince1970)!)
    }
    
    func test(){
        //两个时间对比
        print(getNowTimestamp() - getOtherTimestamp(timesDateString: "2017-07-29 14:20:01"))
    }