如何在 React 组件中每分钟调用一个函数? [英] How to call a function every minute in a React component?

问题描述

我制作了一个表格来获取股票报价，效果很好，但是当我尝试在组件中放置一个包含 setState 的函数时，它陷入了无限循环，它会立即触发 setState 并重新渲染并再次触发.

I make a table to get stock price quotes, it works well, but when I try to put a function include setState in the component, it falls into an infinite loop, it triggers setState and re-render immediately and triggers again.

如何在加载此组件时调用此函数而不触发无限循环?我会每 10 秒或每分钟调用一次该函数.

How can I call this function without triggering an infinite loop when I load this component? I would to call the function every 10 seconds or every minute.

import React, { useState } from 'react'
import api from '../../api'

function CreateRow(props){
    
    const [stock, setStock] = useState({symbol:'',last:'',change:''})
    

    async function check() {
        const result = await api.getStock(props.item)
        console.log(props.item)
        const symbol = result.data.symbol
        const lastest = result.data.latestPrice
        const change = result.data.change
        setStock({symbol:symbol, lastest:lastest, change:change})
    }


    // check()   <----------! if I call the function here, it becomes an infinite loop.


    return(
        <tr>
            <th scope="row"></th>
            <td>{stock.symbol}</td>
            <td>{stock.lastest}</td>
            <td>{stock.change}</td>
        </tr>
    )
}

export default CreateRow

推荐答案

您想在生命周期方法中启动超时函数.

You want to initiate a timeout function inside a lifecycle method.

生命周期方法是调用方法，例如挂载和卸载(示例更多，但为了解释起见，我将在这里停止)

Lifecycle methods are methods which call on, for example, mount and unmount (there are more examples but for the sake of explanation I will stop here)

您感兴趣的是挂载生命周期.

what you're interested in is the mount lifecycle.

在功能组件中，可以这样访问:

In functional components, it can be accessed like this:

const { useEffect } from 'react';

useEffect(() => {
  // This will fire only on mount.
}, [])

在那个函数中，你想初始化一个 setTimeout 函数.

In that function, you want to initialize a setTimeout function.

const MINUTE_MS = 60000;

useEffect(() => {
  const interval = setInterval(() => {
    console.log('Logs every minute');
  }, MINUTE_MS);

  return () => clearInterval(interval); // This represents the unmount function, in which you need to clear your interval to prevent memory leaks.
}, [])

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