How to style components using makeStyles and still have lifecycle methods in Material UI?

问题

I get the below error whenever I try to use makeStyles() with a component with lifecycle methods:

Invalid hook call. Hooks can only be called inside of the body of a function component. This could happen for one of the following reasons:

You might have mismatching versions of React and the renderer (such as React DOM)

You might be breaking the Rules of Hooks

You might have more than one copy of React in the same app

Below is a small example of code that produces this error. Other examples assign classes to child items as well. I can't find anything in MUI's documentation that shows other ways to use makeStyles and have the ability to use lifecycle methods.

    import React, { Component } from 'react';
    import { Redirect } from 'react-router-dom';

    import { Container, makeStyles } from '@material-ui/core';

    import LogoButtonCard from '../molecules/Cards/LogoButtonCard';

    const useStyles = makeStyles(theme => ({
      root: {
        display: 'flex',
        alignItems: 'center',
        justifyContent: 'center',
      },
    }));

    const classes = useStyles();

    class Welcome extends Component {
      render() {
        if (this.props.auth.isAuthenticated()) {
          return <Redirect to="/" />;
        }
        return (
          <Container maxWidth={false} className={classes.root}>
            <LogoButtonCard
              buttonText="Enter"
              headerText="Welcome to PlatformX"
              buttonAction={this.props.auth.login}
            />
          </Container>
        );
      }
    }

    export default Welcome;

回答1:

Hi instead of using hook API, you should use Higher-order component API as mentioned here

I'll modify the example in the documentation to suit your need for class component

import React from 'react';
import PropTypes from 'prop-types';
import { withStyles } from '@material-ui/styles';
import Button from '@material-ui/core/Button';

const styles = theme => ({
  root: {
    background: 'linear-gradient(45deg, #FE6B8B 30%, #FF8E53 90%)',
    border: 0,
    borderRadius: 3,
    boxShadow: '0 3px 5px 2px rgba(255, 105, 135, .3)',
    color: 'white',
    height: 48,
    padding: '0 30px',
  },
});

class HigherOrderComponent extends React.Component {

  render(){
    const { classes } = this.props;
    return (
      <Button className={classes.root}>Higher-order component</Button>
      );
  }
}

HigherOrderComponent.propTypes = {
  classes: PropTypes.object.isRequired,
};

export default withStyles(styles)(HigherOrderComponent);

回答2:

What we ended up doing is stopped using the class components and created Functional Components, using useEffect() from the Hooks API for lifecycle methods. This allows you to still use makeStyles() with Lifecycle Methods without adding the complication of making Higher-Order Components. Which is much simpler.

Example:

import React, { useEffect, useState } from 'react';
import axios from 'axios';
import { Redirect } from 'react-router-dom';

import { Container, makeStyles } from '@material-ui/core';

import LogoButtonCard from '../molecules/Cards/LogoButtonCard';

const useStyles = makeStyles(theme => ({
  root: {
    display: 'flex',
    alignItems: 'center',
    justifyContent: 'center',
    margin: theme.spacing(1)
  },
  highlight: {
    backgroundColor: 'red',
  }
}));

// Highlight is a bool
const Welcome = ({highlight}) => { 
  const [userName, setUserName] = useState('');
  const [isAuthenticated, setIsAuthenticated] = useState(true);
  const classes = useStyles();

  useEffect(() => {
    axios.get('example.com/api/username/12')
         .then(res => setUserName(res.userName));
  }, []);

  if (!isAuthenticated()) {
    return <Redirect to="/" />;
  }
  return (
    <Container maxWidth={false} className={highlight ? classes.highlight : classes.root}>
      <LogoButtonCard
        buttonText="Enter"
        headerText={isAuthenticated && `Welcome, ${userName}`}
        buttonAction={login}
      />
   </Container>
   );
  }
}

export default Welcome;

回答3:

useStyles is a React hook which are meant to be used in functional components and can not be used in class components.

From React:

Hooks let you use state and other React features without writing a class.

Also you should call useStyles hook inside your function like;

function Welcome() {
  const classes = useStyles();
...

If you want to use hooks, here is your brief class component changed into functional component;

import React from "react";
import { Container, makeStyles } from "@material-ui/core";

const useStyles = makeStyles({
  root: {
    background: "linear-gradient(45deg, #FE6B8B 30%, #FF8E53 90%)",
    border: 0,
    borderRadius: 3,
    boxShadow: "0 3px 5px 2px rgba(255, 105, 135, .3)",
    color: "white",
    height: 48,
    padding: "0 30px"
  }
});

function Welcome() {
  const classes = useStyles();
  return (
    <Container className={classes.root}>
      <h1>Welcome</h1>
    </Container>
  );
}

export default Welcome;

🏓 on ↓ CodeSandBox ↓

回答4:

Instead of converting the class to a function, an easy step would be to create a function to include the jsx for the component which uses the 'classes', in your case the <container></container> and then call this function inside the return of the class render() as a tag. This way you are moving out the hook to a function from the class. It worked perfectly for me. In my case it was a <table> which i moved to a function- TableStmt outside and called this function inside the render as <TableStmt/>

来源：https://stackoverflow.com/questions/56432167/how-to-style-components-using-makestyles-and-still-have-lifecycle-methods-in-mat

标签

reactjs

material-ui