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[英]Warning: Can't call setState (or forceUpdate) on an unmounted component in React Native
[英]React Warning: Can't call setState (or forceUpdate) on an unmounted component
我有兩個組件:
訂單 - 獲取一些數據並顯示它。
ErrorHandler - 如果服務器上發生一些錯誤,模態將顯示並顯示一條消息。
ErrorHandler 組件正在扭曲訂單組件
我使用 axios 包在 Orders 組件中加載數據,我使用 axios 攔截器設置有關錯誤的狀態,並在組件卸載后彈出。
當我前后導航到訂單組件時,有時會在控制台中收到錯誤消息:
Warning: Can't call setState (or forceUpdate) on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in the componentWillUnmount method.
in Orders (at ErrorHandler.jsx:40)
in Auxiliary (at ErrorHandler.jsx:34)
in _class2 (created by Route)
我試圖通過我之前的案例來解決它React Warning: Can only update amounted ormounting component但在這里我不能由檢查員制作 axios 令牌。 以前有人解決過這個問題嗎?
這是我的組件:
訂單:
import React, { Component } from 'react';
import api from '../../api/api';
import Order from '../../components/Order/Order/Order';
import ErrorHandler from '../../hoc/ErrorHandler/ErrorHandler';
class Orders extends Component {
state = {
orders: [],
loading: true
}
componentDidMount() {
api.get('/orders.json')
.then(response => {
const fetchedOrders = [];
if (response && response.data) {
for (let key in response.data) {
fetchedOrders.push({
id: key,
...response.data[key]
});
}
}
this.setState({ loading: false, orders: fetchedOrders });
})
.catch(error => {
this.setState({ loading: false });
});
}
render() {
return (
<div>
{this.state.orders.map(order => {
return (<Order
key={order.id}
ingrediencies={order.ingrediencies}
price={order.price} />);
})}
</div>
);
}
}
export default ErrorHandler(Orders, api);
錯誤處理程序:
import React, { Component } from 'react';
import Auxiliary from '../Auxiliary/Auxiliary';
import Modal from '../../components/UI/Modal/Modal';
const ErrorHandler = (WrappedComponent, api) => {
return class extends Component {
requestInterceptors = null;
responseInterceptors = null;
state = {
error: null
};
componentWillMount() {
this.requestInterceptors = api.interceptors.request.use(request => {
this.setState({ error: null });
return request;
});
this.responseInterceptors = api.interceptors.response.use(response => response, error => {
this.setState({ error: error });
});
}
componentWillUnmount() {
api.interceptors.request.eject(this.requestInterceptors);
api.interceptors.response.eject(this.responseInterceptors);
}
errorConfirmedHandler = () => {
this.setState({ error: null });
}
render() {
return (
<Auxiliary>
<Modal
show={this.state.error}
modalClosed={this.errorConfirmedHandler}>
{this.state.error ? this.state.error.message : null}
</Modal>
<WrappedComponent {...this.props} />
</Auxiliary>
);
}
};
};
export default ErrorHandler;
我認為這是由於觸發 setState 的異步調用,即使未安裝組件也可能發生。 為了防止這種情況發生,您可以使用某種標志:
state = {
isMounted: false
}
componentDidMount() {
this.setState({isMounted: true})
}
componentWillUnmount(){
this.state.isMounted = false
}
然后用 if 包裝你的 setState 調用:
if (this.state.isMounted) {
this.setState({ loading: false, orders: fetchedOrders });
}
編輯 - 添加功能組件示例:
function Component() {
const [isMounted, setIsMounted] = React.useState(false);
useEffect(() => {
setIsMounted(true);
return () => {
setIsMounted(false);
}
}, []);
return <div></div>;
}
export default Component;
您不能在 componentWillMount 方法中設置狀態。 嘗試重新考慮您的應用程序邏輯並將其移動到另一種生命周期方法中。
我認為根本原因與我昨天回答的相同,您需要在unmount
上“取消”請求,我不知道您是否正在為Orders
組件中的api.get()
調用執行此操作。
關於錯誤處理的說明,它看起來過於復雜,我絕對鼓勵查看 React 提供的ErrorBoundaries 。 您不需要interceptors
或更高階的組件。
對於 ErrorBoundaries,React 引入了一個名為: componentDidCatch
的生命周期方法。 您可以使用它來簡化您的ErrorHandler
代碼:
class ErrorHandler extends React.Component {
constructor(props) {
super(props);
this.state = { hasError: false };
}
componentDidCatch(error, info) {
this.setState({ hasError: true, errorMessage : error.message });
}
render() {
if (this.state.hasError) {
return <Modal
modalClosed={() => console.log('What do you want user to do? Retry or go back? Use appropriate method logic as per your need.')}>
{this.state.errorMessage ? this.state.errorMessage : null}
</Modal>
}
return this.props.children;
}
}
然后在您的Orders
組件中:
class Orders extends Component {
let cancel;
state = {
orders: [],
loading: true
}
componentDidMount() {
this.asyncRequest = api.get('/orders.json', {
cancelToken: new CancelToken(function executor(c) {
// An executor function receives a cancel function as a parameter
cancel = c;
})
})
.then(response => {
const fetchedOrders = [];
if (response && response.data) {
for (let key in response.data) {
fetchedOrders.push({
id: key,
...response.data[key]
});
}
}
this.setState({ loading: false, orders: fetchedOrders });
})
.catch(error => {
this.setState({ loading: false });
// please check the syntax, I don't remember if it is throw or throw new
throw error;
});
}
componentWillUnmount() {
if (this.asyncRequest) {
cancel();
}
}
render() {
return (
<div>
{this.state.orders.map(order => {
return (<Order
key={order.id}
ingrediencies={order.ingrediencies}
price={order.price} />);
})}
</div>
);
}
}
並在您的代碼中使用它作為:
<ErrorHandler>
<Orders />
</ErrorHandler>
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