Question

当我尝试使用React Router时出现此错误，并且在我的reactjs环境中注意到一切正常，但是当我运行npm run build file时，React Router不起作用，

这是一个完整的错误，我发现控制台需要对其进行修复。

index.js:1 Warning: Can't perform a React state update 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 TextTypeEffect (at carousel.js:8)
    in div (at carousel.js:7)
    in div (at carousel.js:6)
    in Carousel (at App.js:71)
    in Home (at App.js:41)

Answer 1

在组件卸载后组件尝试设置状态时会发生这种情况，因此您需要在componentWillUnmount()中取消订阅状态更新下面是类组件的示例代码

import React, { Component } from 'react';

class MyComponent extends Component {

    _isMounted = false;

    componentDidMount() {
        this._isMounted = true;
    }

    componentWillUnmount = () => this._isMounted = false;

    setState = (state, callback) => this._isMounted && super.setState(state, callback);
}

Answer 2

尝试取消订阅您的状态，该组件内部出现错误：例如

 const [didMount, setDidMount] = useState(false); 

    useEffect(() => {
     setDidMount(true);
     //You need to unsubscribe before un-mounting component
     return () => setDidMount(false);
    }, [])

如何解决ReactJs无法在未安装的组件上执行React状态更新

2 个答案: