【发布时间】：2020-02-16 01:07:28
【问题描述】：
我正在尝试使用材料 ui 中的代码并收到此错误：
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:
1. You might have mismatching versions of React and the renderer (such as React DOM)
2. You might be breaking the Rules of Hooks
3. You might have more than one copy of React in the same app
如果我不使用类，我不确定是什么导致了问题（因为我知道反应钩子不能在类中使用）。我想知道这是否与 ReactDOM 有关？
这是我使用的唯一代码：
=======index.js=======
import React from 'react';
import ReactDOM from 'react-dom';
import App from './Pages/HomePage.jsx';
ReactDOM.render(<App />, document.getElementById('root'));
=======HomePage.js=======
import React, { useState } from 'react';
import AB from '../Components/AppBar';
export default function HP() {
const [buttonClicked, setButtonClicked] = useState(false);
if (buttonClicked === false )
return (
<Button color="info" onClick={() => setButtonClicked(true)}>Get Started</Button>
)
if (buttonClicked) return (<AB/>)
};
=======AppBar.js=======
import React from 'react';
import AppBar from '@material-ui/core/AppBar';
import Toolbar from '@material-ui/core/Toolbar';
import IconButton from '@material-ui/core/IconButton';
import Typography from '@material-ui/core/Typography';
import InputBase from '@material-ui/core/InputBase';
import { fade, makeStyles } from '@material-ui/core/styles';
import MenuIcon from '@material-ui/icons/Menu';
import SearchIcon from '@material-ui/icons/Search';
const useStyles = makeStyles(theme => ({
root: {
flexGrow: 1,
},
menuButton: {
marginRight: theme.spacing(2),
},
title: {
flexGrow: 1,
display: 'none',
[theme.breakpoints.up('sm')]: {
display: 'block',
},
},
search: {
position: 'relative',
borderRadius: theme.shape.borderRadius,
backgroundColor: fade(theme.palette.common.white, 0.15),
'&:hover': {
backgroundColor: fade(theme.palette.common.white, 0.25),
},
marginLeft: 0,
width: '100%',
[theme.breakpoints.up('sm')]: {
marginLeft: theme.spacing(1),
width: 'auto',
},
},
searchIcon: {
width: theme.spacing(7),
height: '100%',
position: 'absolute',
pointerEvents: 'none',
display: 'flex',
alignItems: 'center',
justifyContent: 'center',
},
inputRoot: {
color: 'inherit',
},
inputInput: {
padding: theme.spacing(1, 1, 1, 7),
transition: theme.transitions.create('width'),
width: '100%',
[theme.breakpoints.up('sm')]: {
width: 120,
'&:focus': {
width: 200,
},
},
},
}));
export default function SearchAppBar() {
const classes = useStyles();
return (
<div className={classes.root}>
<AppBar position="static">
<Toolbar>
<IconButton
edge="start"
className={classes.menuButton}
color="inherit"
aria-label="open drawer"
>
<MenuIcon />
</IconButton>
<Typography className={classes.title} variant="h6" noWrap>
Material-UI
</Typography>
<div className={classes.search}>
<div className={classes.searchIcon}>
<SearchIcon />
</div>
<InputBase
placeholder="Search…"
classes={{
root: classes.inputRoot,
input: classes.inputInput,
}}
inputProps={{ 'aria-label': 'search' }}
/>
</div>
</Toolbar>
</AppBar>
</div>
);
}
【问题讨论】：
-
检查项目中的点 1 和 3
-
我都检查过了，看起来还不错。没有重复或版本不匹配。它们都是 16.10.2
-
请粘贴实际的错误日志..来自控制台的完整日志
-
代码明智好。检查第三点或使用新文件夹
标签： javascript reactjs components material-ui react-hooks