/**
       * dateTimeStamp是评论的发送时间   2020-01-12 20:10:15 这样的形式
       * @param dateTimeStamp
       * @returns {string}
       */
      timeAgo(dateTimeStamp) {
        let result = "";
        let minute = 1000 * 60;      //把分，时，天，周，半个月，一个月用毫秒表示
        let hour = minute * 60;
        let day = hour * 24;
        let week = day * 7;
        let halfamonth = day * 15;
        let month = day * 30;
        let now = new Date().getTime();   //获取当前时间毫秒

        dateTimeStamp = dateTimeStamp.substring(0, 18);
        //必须把日期'-'转为'/'
        dateTimeStamp = dateTimeStamp.replace(/-/g, '/');
        let timestamp = new Date(dateTimeStamp).getTime();

        let diffValue = now - timestamp;//时间差

        if (diffValue < 0) {
          return result;
        }
        let minC = diffValue / minute;  //计算时间差的分，时，天，周，月
        let hourC = diffValue / hour;
        let dayC = diffValue / day;
        let weekC = diffValue / week;
        let monthC = diffValue / month;
        if (monthC >= 1 && monthC <= 3) {
          result = " " + parseInt(monthC) + "月前"
        } else if (weekC >= 1 && weekC <= 3) {
          result = " " + parseInt(weekC) + "周前"
        } else if (dayC >= 1 && dayC <= 6) {
          result = " " + parseInt(dayC) + "天前"
        } else if (hourC >= 1 && hourC <= 23) {
          result = " " + parseInt(hourC) + "小时前"
        } else if (minC >= 1 && minC <= 59) {
          result = " " + parseInt(minC) + "分钟前"
        } else if (diffValue >= 0 && diffValue <= minute) {
          result = "刚刚"
        } else {
          let datetime = new Date();
          datetime.setTime(dateTimeStamp);
          let Nyear = datetime.getFullYear();
          let Nmonth = datetime.getMonth() + 1 < 10 ? "0" + (datetime.getMonth() + 1) : datetime.getMonth() + 1;
          let Ndate = datetime.getDate() < 10 ? "0" + datetime.getDate() : datetime.getDate();
          let Nhour = datetime.getHours() < 10 ? "0" + datetime.getHours() : datetime.getHours();
          let Nminute = datetime.getMinutes() < 10 ? "0" + datetime.getMinutes() : datetime.getMinutes();
          let Nsecond = datetime.getSeconds() < 10 ? "0" + datetime.getSeconds() : datetime.getSeconds();
          result = Nyear + "-" + Nmonth + "-" + Ndate
        }
        return result;
      },