正确使用 async 函数和 useEffect 是一个常见的问题,因为在 useEffect 中直接使用 async 函数会导致一些问题。这是因为 useEffect 函数本身不能直接返回 Promise。下面是一种正确使用 async 函数和 useEffect 的方法: 代码语言:txt 复制 import React, { useEffect } from 'react'; function MyComponent() { useEffe...
We make fetchTopPlayers() an async function so that we can use await within it. I gotta admit, having to define the inner function is a bit clunky. But, in my opinion, it's a small price to pay to drastically improve the developer experience of async useEffect calls. You know, what...
@kentcdodds Let me add this for additional consideration: the testing library does NOT cause my clean-up function to be called. I am following best practices in my useEffects to not do async updates when my component is torn down. Now my tests need to concern themselves with things that ...
卸载的时候会通过函数组件对应的 fiber 获取 effect 链表,然后遍历链表,获取环链上的每一个节点,如果 destroy 不是 undefined 就执行,所以如果 useEffect 第一个参数传入 async, 那么这里的 destroy 就是一个 promise 对象,对象是不能执行的,所以报错。 functioncommitHookEffectListUnmount(tag, finishedWork) {varu...
useEffect(() => { (async function fn() { const response = await selectReceiveMaterialRecord({ billDetailId: billDetailId, }); form.setFieldsValue({ materielId: response.data?.materialName }); setMaterielId(response.data?.materialId); ...
chaining, which will not be a best pracitce in the future versions of React. This would be still useful for learning and might work for small projects. React community should move to new data fetching approach, or at least approach to fire a single async function in useEffect. See also:#...
When you use useEffect, if you use async...await... in the callback function, the following error will be reported. Looking at the error report, we know that theeffect function should return a destroy function (effect: refers to the cleanup function returned by return). If the first para...
The API is the same as React'suseEffect(), except for some notable differences: The destroy function is passed as an optional second argument: useAsyncEffect(callback,dependencies?);useAsyncEffect(callback,onDestroy,dependencies?); The async callback will receive a single function to check wheth...
但在React应用程序中,它迫使我执行useEffect,然后更新状态。如果我返回一个格式化的对象,比如:{loading, error, data},是否可以通过这种方式直接访问它: const {loading, error, data} = fetchData() 如何允许从这样的函数直接访问对象: async function foo(){const res = ...
function Dashboard() { const [token, setToken] = useState(''); useEffect(() => { // React advises to declare the async function directly inside useEffect async function getToken() { const headers = { Authorization: authProps.idToken // using Cognito authorizer }; const response = await...