reactjs – React无状态组件中的箭头函数语法

import { Component,PropTypes } from 'react';

export default function ClassroomsOverview(props,context) {
  return (
    <div>
      <p>{context.classrooms.data.length} Classrooms.</p>
      <p>{context.classrooms.members.length} Students</p>
    </div>
  );
}

ClassroomsOverview.contextTypes = {
  classrooms: PropTypes.object
}

如果我可以使用E6 arrow function syntax使相同的组件工作,我会更高兴,就像这样：

import { Component,PropTypes } from 'react';

const ClassroomsOverview = (props,context) => (
    <div>
      <p>{context.classrooms.data.length} Classrooms.</p>
      <p>{context.classrooms.members.length} Students</p>
    </div>
  );

ClassroomsOverview.contextTypes = {
  classrooms: PropTypes.object
}

我已经遵循了this video,但我无法使用箭头语法版本.

任何人都可以指出我做错了吗？