时间戳转换为日期格式（YYYY-MM-dd HH:mm:ss）

getFormatTime(datetime) {
      let time = new Date(datetime*1000)//时间戳为10位要*1000，13位不用*1000
      let year = time.getFullYear()
      let month = time.getMonth() + 1
      let date = time.getDate()
      let hours = time.getHours()
      let minute = time.getMinutes()
      let second = time.getSeconds()
      if (month < 10) { month = '0' + month }
      if (date < 10) { date = '0' + date }
      if (hours < 10) { hours = '0' + hours }
      if (minute < 10) { minute = '0' + minute }
      if (second < 10) { second = '0' + second }
      return year + '/' + month + '/' + date + ' ' + hours + ':' + minute
    }