当前主题在本地存储时，如何在浅色和深色主题之间切换？

问题描述

我还很陌生，我正在使用Material-UI实现一些新功能。我正在尝试在当前主题本地存储在浏览器中的同时在浅色和深色主题之间切换。我希望在页面刷新时将当前主题存储在本地。默认情况下，我的应用会加载浅色主题。在切换开关之前，我验证了灯光主题是否在本地存储中。当我切换到深色主题时，我的应用程序将更改为对应的主题，并且本地存储中的值将按预期更改。但是，当我尝试将开关切换回浅色主题时，主题不会改变，只会改变我的本地存储值。我不知道为什么。

如果有人可以通过调整代码来解决此问题或提出新的想法，我将不胜感激。

您将在下面找到code：（请忽略控制台中的StrictMode错误）

CustomThemeContext.js

import React,{ useState,createContext } from 'react';
import { ThemeProvider } from '@material-ui/core/styles';
import getTheme from '../components/MyThemes';
import Paper from '@material-ui/core/Paper';

export const CustomThemeContext = createContext(
  {
    currentTheme: 'normalTheme',setTheme: null,},);

const CustomThemeProvider = (props) => {
  const { children } = props
  const currentTheme = localStorage.getItem('appTheme') || 'normalTheme'
  const [themeName,_setThemeName] = useState(currentTheme)
  const theme = getTheme(themeName)
  const setThemeName = (name) => {
    localStorage.setItem('appTheme',name)
    _setThemeName(name)
  }
  const contextValue = {
    currentTheme: themeName,setTheme: setThemeName,}
  const paperStyle = {
    height: "100vh",}

  return (
    <div>
      <CustomThemeContext.Provider value={contextValue}>
        <ThemeProvider theme={theme}>
          <Paper style={paperStyle}>
            {children}
          </Paper>
        </ThemeProvider>
      </CustomThemeContext.Provider>
    </div>
  )
}

export default CustomThemeProvider;

index.js

import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';
import App from './App';
import * as serviceWorker from './serviceWorker';
import CustomThemeProvider from './contexts/CustomThemeProvider';

ReactDOM.render(
  <React.StrictMode>
    <CustomThemeProvider>
      <App />
    </CustomThemeProvider>
  </React.StrictMode>,document.getElementById('root')
);

serviceWorker.unregister();

App.js

import React,{ useContext } from 'react';
import { makeStyles } from '@material-ui/core/styles';
import { CustomThemeContext } from './contexts/CustomThemeProvider';
import AppBar from '@material-ui/core/AppBar';
import Toolbar from '@material-ui/core/Toolbar';
import Tooltip from '@material-ui/core/Tooltip';
import Typography from '@material-ui/core/Typography';
import BurgerButton from './components/BurgerButton';
import StarButton from './components/StarButton';
import Switch from '@material-ui/core/Switch';
import Button from '@material-ui/core/Button';
import AddCircleIcon from '@material-ui/icons/AddCircle';
import FormControlLabel from '@material-ui/core/FormControlLabel';

const useStyles = makeStyles((theme) => ({
  root: {
    flexGrow: 1,width: 'auto',title: {
    flexGrow: 1,content: {
    flexGrow: 1,padding: theme.spacing(3),}
}));

export default function App() {
  const classes = useStyles();
  const { currentTheme,setTheme } = useContext(CustomThemeContext);
  const isDark = Boolean(currentTheme === 'darkTheme')

  const handleThemeChange = (event) => {
    const { checked } = event.target
    if (checked) {
      setTheme('darkTheme')
    } else {
      setTheme('normalTheme')
    }
  }

  /*
  switch (checked) {
    case 'darkTheme':
      return setTheme('darkTheme');
    case 'normalTheme':
      return setTheme('normalTheme');
    default:
      return null;
  }
  */

  return (
    <div className="App">
      <div className={classes.root}>
        <AppBar position="static" title="Memo App">
          <Toolbar>
            <BurgerButton />
            <Typography variant="h6" className={classes.title}>
              Memo App
            </Typography>
            <Tooltip title="Toggle light theme/dark theme">
              <FormControlLabel
                control={<Switch checked={isDark} onChange={handleThemeChange} />}
                label="Theme"
              />
            </Tooltip>
            <StarButton />
          </Toolbar>
        </AppBar>
        <Button>
          <AddCircleIcon />
        </Button>
      </div>
    </div>
  );
}

MyThemes.js

import normalTheme from './themes/normalTheme';
import darkTheme from './themes/darkTheme';

const themes = {
  normalTheme,darkTheme,}

export default function getTheme(theme) {
  return themes[theme]
}

解决方法

在您的ThemeProvider组件theme道具上，克隆分配给它的主题对象，它应该可以工作

<ThemeProvider theme={{...theme}}>
  <Paper style={paperStyle}>
    {children}
  </Paper>
</ThemeProvider>