--- title: 'react报错：Can‘t perform a React state update on an unmounted component' date: 2021-07-24 11:54:00 ---   解决方案： ```javascript //生成cancelToken，用于取消请求 const getCancelSource = () => { return axios.CancelToken.source() } //挂载时异步获取所属分类数据 useEffect(() => { const source = getCancelSource() Api.light.category(source.token).then((res) => { if (res.state === 1) { const category = formatCategory({ categoryOptions: res.data }) setCategoryOptions(category) console.log('category') } }).catch(err => { console.log(err) }) return () => { console.log('卸载') source.cancel() } }, []) ```   参考链接：[http://www.axios-js.com/zh-cn/docs/#%E5%8F%96%E6%B6%88](http://www.axios-js.com/zh-cn/docs/#%E5%8F%96%E6%B6%88) ```javascript const CancelToken = axios.CancelToken; const source = CancelToken.source(); axios.get('/user/12345', { cancelToken: source.token }).catch(function(thrown) { if (axios.isCancel(thrown)) { console.log('Request canceled', thrown.message); } else { // 处理错误 } }); axios.post('/user/12345', { name: 'new name' }, { cancelToken: source.token }) // 取消请求（message 参数是可选的） source.cancel('Operation canceled by the user.'); ``` axios config的一个字段： ```javascript // `cancelToken` 指定用于取消请求的 cancel token // （查看后面的 Cancellation 这节了解更多） cancelToken: new CancelToken(function (cancel) { }) ```