js倒计时

根据实际经过的时间动态调整下一次更新的时间，从而减少延迟问题

  const countdown = (endTime: any, onUpdate: any, onEnd: any) => {
    const updateInterval = 1000; // 更新间隔（毫秒）
    let lastUpdateTime = new Date().getTime();
    const update = () => {
      const currentTime = new Date().getTime();
      const remainingTime = Math.max(endTime - currentTime, 0);
      const seconds = Math.floor((remainingTime % (1000 * 60)) / 1000);
      const minutes = Math.floor(
        (remainingTime % (1000 * 60 * 60)) / (1000 * 60),
      );
      const hours = Math.floor(
        (remainingTime % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60),
      );
      const days = Math.floor(remainingTime / (1000 * 60 * 60 * 24));

      onUpdate({ days, hours, minutes, seconds });

      if (remainingTime <= 0) {
        clearInterval(intervalId);
        onEnd();
      } else {
        const elapsedTime = currentTime - lastUpdateTime;
        const nextUpdateInterval =
          updateInterval - (elapsedTime % updateInterval);
        setTimeout(update, nextUpdateInterval);
        lastUpdateTime = currentTime;
      }
    };
    const intervalId = setTimeout(update, updateInterval);
  };
  const endTime = new Date().getTime() + 1000 * 60 * 60 * 24;
  countdown(
    endTime,
    ({ days, hours, minutes, seconds }:any) => {
      console.log(`倒计时：${days}天 ${hours}小时 ${minutes}分钟 ${seconds}秒`);
    },
    () => {
      console.log('倒计时结束');
    }
  );