Vue 按照创建时间和当前时间显示（刚刚，几小时前，几天前）
在methods中创建方法showtime，传入要跟当前时间要对比的时间

    showtime(time) {
      let date =
        typeof time === "number"
          ? new Date(time)
          : new Date((time || "").replace(/-/g, "/"));
      let diff = (new Date().getTime() - date.getTime()) / 1000;
      let dayDiff = Math.floor(diff / 86400);

      let isValidDate =
        Object.prototype.toString.call(date) === "[object Date]" &&
        !isNaN(date.getTime());

      if (!isValidDate) {
        window.console.error("不是有效日期格式");
      }
      const formatDate = function(date) {
        let today = new Date(date);
        let year = today.getFullYear();
        let month = ("0" + (today.getMonth() + 1)).slice(-2);
        let day = ("0" + today.getDate()).slice(-2);
        let hour = today.getHours();
        let minute = today.getMinutes();
        let second = today.getSeconds();
        return `${year}-${month}-${day} ${hour}:${minute}:${second}`;
      };
         //小于0或者大于等于31显示原时间
      if (isNaN(dayDiff) || dayDiff < 0 || dayDiff >= 31) {
        return formatDate(date);
      }
      return (
        (dayDiff === 0 &&
          ((diff < 60 && "刚刚") ||
            (diff < 120 && "1分钟前") ||
            (diff < 3600 && Math.floor(diff / 60) + "分钟前") ||
            (diff < 7200 && "1小时前") ||
            (diff < 86400 && Math.floor(diff / 3600) + "小时前"))) ||
        (dayDiff === 1 && "昨天") ||
        (dayDiff < 7 && dayDiff + "天前") ||
        (dayDiff < 31 && Math.ceil(dayDiff / 7) + "周前")
      );
    },