text: import React from 'react';
  import PropTypes from 'prop-types';
  import classNames from 'classnames';
  
  import { withStyles } from '@material-ui/core/styles';
  
  import IconButton from '@material-ui/core/IconButton';
  
  import MenuIcon from 'mdi-material-ui/Menu';
  
  const styles = theme => ({
    menuButton: {
      margin: theme.spacing(2),
      zIndex: theme.zIndex.drawer - 1,
      position: 'absolute',
      left: 0,
      top: 0
    }
  });
  
  class MainAppbar extends React.Component {
    static propTypes = {
      // Dispatcher
      onToggleDrawer: PropTypes.func
    }
  
    render() {
      const { classes } = this.props;
  
      return (
        <div>
          <IconButton
            color='inherit'
            aria-label='打开侧边栏'
            onClick={this.props.onToggleDrawer}
            className={classes.menuButton}
          >
            <MenuIcon />
          </IconButton>
        </div>
      )
    }
  }
  
  export default withStyles(styles)(MainAppbar);
  