material ui withStyles和WithTheme -如何访问主题

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

const styles = theme => ({
  root: {
    backgroundColor: theme.palette.primary.main,
    color: theme.palette.primary.contrastText,
    padding: theme.spacing(2),
  },
});

const MyComponent = ({ classes }) => (
  <div className={classes.root}>
    This is a styled component using withStyles.
  </div>
);

export default withStyles(styles)(MyComponent);

import React from 'react';
import { withStyles, withTheme } from '@material-ui/core/styles';

const styles = theme => ({
  root: {
    backgroundColor: theme.palette.primary.main,
    color: theme.palette.primary.contrastText,
    padding: theme.spacing(2),
  },
});

const MyComponent = ({ classes, theme }) => (
  <div className={classes.root}>
    This is a styled component using withStyles and withTheme.
    The primary color is {theme.palette.primary.main}.
  </div>
);

export default withStyles(styles)(withTheme(MyComponent));