Javascript 反应时间间隔内存泄漏

我创建了一个倒计时计时器组件，将数据传递给另一个组件，并使用

setTimeout

。组件按预期工作，但“我的控制台”中出现警告：

警告：无法对已卸载的组件执行React状态更新。这是一个no-op，但它表示应用程序中存在内存泄漏。要修复此问题，请取消useEffect清理函数中的所有订阅和异步任务

当我在

useffect

中使用

setTimeout

时，我试图在返回函数中添加

clearInterval

，但这似乎没有帮助。下面您可以找到我的组件：

export default function createEvent(WrappedComponent) {
  const Event = props => {
    const [{ endDate }] = useState(props);
    const [days, setDays] = useState('');
    const [hours, setHours] = useState('');
    const [minutes, setMinutes] = useState('');
    const [seconds, setSeconds] = useState('');

    const interval = useRef();

    useEffect(() => {
      interval.current = setInterval(() => {
        const date = moment.unix(endDate).format('MM DD YYYY, h:mm a');
        const then = moment(date, 'MM DD YYYY, h:mm a');
        const now = moment();
        const countdown = moment(then - now);
        const daysFormat = countdown.format('D');
        const hoursFormat = countdown.format('HH');
        const minutesFormat = countdown.format('mm');
        const secondsFormat = countdown.format('ss');

        setDays(`${daysFormat} days`);
        setHours(hoursFormat);
        setMinutes(minutesFormat);
        setSeconds(secondsFormat);

        return () => {
          clearInterval(interval.current);
          interval.current = null;
        };
      }, 1000);
    }, []);

    return (
      <WrappedComponent
        days={days}
        hours={hours}
        minutes={minutes}
        seconds={seconds}
        {...props}
      />
    );
  };

  return Event;
}

警告消失，但倒计时将不再工作。那么，我如何才能做到这一点，不影响倒计时并清除警告

useEffect(() => {
      interval.current = setInterval(() => {
        const date = moment.unix(endDate).format('MM DD YYYY, h:mm a');
        const then = moment(date, 'MM DD YYYY, h:mm a');
        const now = moment();
        const countdown = moment(then - now);
        const daysFormat = countdown.format('D');
        const hoursFormat = countdown.format('HH');
        const minutesFormat = countdown.format('mm');
        const secondsFormat = countdown.format('ss');

        setDays(`${daysFormat} days`);
        setHours(hoursFormat);
        setMinutes(minutesFormat);
        setSeconds(secondsFormat);
      }, 1000);

  // Attention : return function cleanup for the function used in useEffect()
  return () => {
      clearInterval(interval.current);
      interval.current = null;
    };
}, []);

---

您可以在此处查看我的完整答案“清除React Hooks中未安装组件上的内存泄漏：

需要从提供给

useffect

的函数返回

useffect

钩子[1]的清除函数。您正在将清除函数返回给

setInterval

的函数中

useEffect(() => {
  interval.current = setInterval(() => {
    const date = moment.unix(endDate).format('MM DD YYYY, h:mm a');
    const then = moment(date, 'MM DD YYYY, h:mm a');
    const now = moment();
    const countdown = moment(then - now);
    const daysFormat = countdown.format('D');
    const hoursFormat = countdown.format('HH');
    const minutesFormat = countdown.format('mm');
    const secondsFormat = countdown.format('ss');

    setDays(`${daysFormat} days`);
    setHours(hoursFormat);
    setMinutes(minutesFormat);
    setSeconds(secondsFormat);
  }, 1000);

  // move clean up function to here:
  return () => {
    clearInterval(interval.current);
    interval.current = null;
  };
}, []);

useEffect(() => {
      const timer = setInterval(() => {
        const date = moment.unix(endDate).format('MM DD YYYY, h:mm a');
        const then = moment(date, 'MM DD YYYY, h:mm a');
        const now = moment();
        const countdown = moment(then - now);
        const daysFormat = countdown.format('D');
        const hoursFormat = countdown.format('HH');
        const minutesFormat = countdown.format('mm');
        const secondsFormat = countdown.format('ss');

        setDays(`${daysFormat} days`);
        setHours(hoursFormat);
        setMinutes(minutesFormat);
        setSeconds(secondsFormat);

      }, 1000);

       return () => {
          clearInterval(timer);
        };
    }, []);

---

[1] 对于

效果

，您不需要

createRef

。并在间隔后返回

useEffect(() => {
  interval.current = setInterval(() => {
    const date = moment.unix(endDate).format('MM DD YYYY, h:mm a');
    const then = moment(date, 'MM DD YYYY, h:mm a');
    const now = moment();
    const countdown = moment(then - now);
    const daysFormat = countdown.format('D');
    const hoursFormat = countdown.format('HH');
    const minutesFormat = countdown.format('mm');
    const secondsFormat = countdown.format('ss');

    setDays(`${daysFormat} days`);
    setHours(hoursFormat);
    setMinutes(minutesFormat);
    setSeconds(secondsFormat);
  }, 1000);

  // move clean up function to here:
  return () => {
    clearInterval(interval.current);
    interval.current = null;
  };
}, []);

useEffect(() => {
      const timer = setInterval(() => {
        const date = moment.unix(endDate).format('MM DD YYYY, h:mm a');
        const then = moment(date, 'MM DD YYYY, h:mm a');
        const now = moment();
        const countdown = moment(then - now);
        const daysFormat = countdown.format('D');
        const hoursFormat = countdown.format('HH');
        const minutesFormat = countdown.format('mm');
        const secondsFormat = countdown.format('ss');

        setDays(`${daysFormat} days`);
        setHours(hoursFormat);
        setMinutes(minutesFormat);
        setSeconds(secondsFormat);

      }, 1000);

       return () => {
          clearInterval(timer);
        };
    }, []);

天哪，我怎么没注意到…）疯狂的我。。。感谢您关注@sdgluck