React + Material UI技术问题求助：makeStyles导入冲突与DefaultTheme类型报错

Hey there! Let's break down and fix both of your problems one by one.

1. Fixing: Property 'transitions' does not exist on type 'DefaultTheme' #

This is a TypeScript type mismatch issue. The DefaultTheme interface from Material UI doesn't include all theme properties (like transitions) by default in some setups. Here are two straightforward fixes:

Option 1: Use the Correct Theme Type #

Instead of relying on DefaultTheme, import the full Theme type directly from @material-ui/core/styles—it includes all Material UI theme properties out of the box. Example:

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

const useStyles = makeStyles((theme: Theme) => ({
  fadeIn: {
    transition: theme.transitions.create('opacity', {
      duration: theme.transitions.duration.short,
    }),
  },
}));

Option 2: Augment the DefaultTheme Interface #

If you prefer to keep using DefaultTheme, create a declaration file to extend it. Make a file named src/types/material-ui.d.ts (any path under your src folder works) with this code:

import { DefaultTheme } from '@material-ui/core/styles';
import { Transitions } from '@material-ui/core/styles/createTransitions';

declare module '@material-ui/core/styles' {
  interface DefaultTheme {
    transitions: Transitions;
  }
}

This tells TypeScript that DefaultTheme includes the transitions property.

2. Fixing: makeStyles Import Warning + 'theme is undefined' Error #

The warning to import makeStyles from @material-ui/styles is correct (since @material-ui/core/styles/makeStyles is deprecated in newer versions), but the "theme undefined" error happens because the standalone makeStyles needs proper integration with your app's theme context. Here's how to fix it:

Step 1: Ensure Dependencies Are Installed #

First, confirm you have both required packages:

npm install @material-ui/core @material-ui/styles
# or
yarn add @material-ui/core @material-ui/styles

Step 2: Wrap Your App with StylesProvider and ThemeProvider #

The standalone makeStyles uses its own context, so you need to wrap your root component with StylesProvider from @material-ui/styles to connect it to your theme. Example root component:

import React from 'react';
import { ThemeProvider, createMuiTheme } from '@material-ui/core/styles';
import { StylesProvider } from '@material-ui/styles';
import YourAppContent from './YourAppContent';

// Create your custom theme (or use the default)
const theme = createMuiTheme({
  palette: {
    primary: { main: '#1976d2' },
  },
});

function App() {
  return (
    <StylesProvider>
      <ThemeProvider theme={theme}>
        <YourAppContent />
      </ThemeProvider>
    </StylesProvider>
  );
}

export default App;

Step 3: Use makeStyles from @material-ui/styles Correctly #

Now, in your components, import makeStyles from @material-ui/styles and pair it with the full Theme type for TypeScript safety:

import { makeStyles } from '@material-ui/styles';
import { Theme } from '@material-ui/core/styles';

const useStyles = makeStyles((theme: Theme) => ({
  container: {
    padding: theme.spacing(2),
    backgroundColor: theme.palette.background.paper,
  },
}));

function MyComponent() {
  const classes = useStyles();
  return <div className={classes.container}>Hello World</div>;
}

This setup ensures makeStyles has access to the theme provided by ThemeProvider, eliminating both the warning and the "theme undefined" error.

内容的提问来源于stack exchange，提问作者Praveen Kumar