class Parent extends React.Component {
  static childContextTypes = {
    data: PropTypes.string
  }

  getChildContext () {
    return {
      data: "data"
    }
  }

  render() {
    return (
      <Child />
    )
  }
}

class Child extends React.Component {
  static contextTypes = {
    data: PropTypes.string
  }

  render() {
    return (
      <div>Child中获取Context：{this.context.data}</div>
    )
  }
}

ReactDOM.render(<Parent />, document.getElementById("root"))