javascript - react 警告 : Can't call setState (or forceUpdate) on an unmounted component

Question

我有两个组件:
订单 - 获取一些数据并显示它。
ErrorHandler - 如果服务器发生错误，模式将显示并显示一条消息。
ErrorHandler 组件正在扭曲订单组件

我使用 axios 包加载订单组件中的数据，我使用 axios 拦截器来设置有关错误的状态，并在组件卸载后弹出。

当我来回导航到订单组件时，我有时会在控制台中收到错误消息:

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)

我试图通过我以前的案例解决它React Warning: Can only update a mounted or mounting component但在这里我不能让检查员制作 axios token 。以前有人解决过这个问题吗？

这是我的组件:

订单:

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);

错误处理程序:

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;

Answer 1

我认为这是由于触发 setState 的异步调用所致，即使组件未安装也可能发生。为防止这种情况发生，您可以使用某种标志:

  state = {
    isMounted: false
  }
  componentDidMount() {
      this.setState({isMounted: true})
  }
  componentWillUnmount(){
      this.state.isMounted = false
  }

然后用 if 包装你的 setState 调用:

if (this.state.isMounted) {
   this.setState({ loading: false, orders: fetchedOrders });
}

编辑 - 添加功能组件示例:

function Component() {
  const [isMounted, setIsMounted] = React.useState(false);

  useEffect(() => {
    setIsMounted(true);
    return () => {
      setIsMounted(false);
    }
  }, []);

  return <div></div>;
}

export default Component;