如何防止我的功能组件使用 React 备忘录或 React 钩子重新渲染? [英] How can I prevent my functional component from re-rendering with React memo or React hooks?

问题描述

当 hiddenLogo 改变值时，组件被重新渲染.我希望这个组件永远重新渲染，即使它的道具改变了.使用类组件，我可以通过像这样实现 sCU 来做到这一点:

When hiddenLogo changes value, the component is re-rendered. I want this component to never re-render, even if its props change. With a class component I could do this by implementing sCU like so:

shouldComponentUpdate() {
  return false;
}

但是有没有办法处理 React hooks/React memo?

But is there a way to do with with React hooks/React memo?

这是我的组件的样子:

import React, { useEffect } from 'react';
import PropTypes from 'prop-types';

import ConnectedSpringLogo from '../../containers/ConnectedSpringLogo';

import { Wrapper, InnerWrapper } from './styles';
import TitleBar from '../../components/TitleBar';

const propTypes = {
  showLogo: PropTypes.func.isRequired,
  hideLogo: PropTypes.func.isRequired,
  hiddenLogo: PropTypes.bool.isRequired
};

const Splash = ({ showLogo, hideLogo, hiddenLogo }) => {
  useEffect(() => {
    if (hiddenLogo) {
      console.log('Logo has been hidden');
    }
    else {
      showLogo();

      setTimeout(() => {
        hideLogo();
      }, 5000);
    }
  }, [hiddenLogo]);

  return (
    <Wrapper>
      <TitleBar />
      <InnerWrapper>
        <ConnectedSpringLogo size="100" />
      </InnerWrapper>
    </Wrapper>
  );
};

Splash.propTypes = propTypes;

export default Splash;

推荐答案

正如 G.aziz 所说，React.memo 的功能类似于纯组件.但是，您也可以通过向它传递一个定义相等的函数来调整其行为.基本上，这个函数是shouldComponentUpdate，除非你希望它不呈现，你会返回true.

As G.aziz said, React.memo functions similarly to pure component. However, you can also adjust its behavior by passing it a function which defines what counts as equal. Basically, this function is shouldComponentUpdate, except you return true if you want it to not render.

const areEqual = (prevProps, nextProps) => true;

const MyComponent = React.memo(props => {
  return /*whatever jsx you like */
}, areEqual);

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