react-router中嵌套的子组件拿location对象的问题
比如说一个页面有个modal组件，modal组件里面的内容写在子组件里面(ModalDetail),在这个组件里面拿不到this.props.location，求解答，除了从父组件传进去和通过window对象拿，还有什么方法
react-router v4之前的版本，有一个叫做`withRouter`的高阶组件。你在定义自己的modal组件时包一层即可。
v4版本暂时没有用过，有没有改动不清楚
```
import React from 'react'
import PropTypes from 'prop-types'
import { withRouter } from 'react-router'

// A simple component that shows the pathname of the current location
class ShowTheLocation extends React.Component {
  static propTypes = {
    match: PropTypes.object.isRequired,
    location: PropTypes.object.isRequired,
    history: PropTypes.object.isRequired
  }

  render() {
    const { match, location, history } = this.props

    return (
      <div>You are now at {location.pathname}</div>
    )
  }
}

// Create a new component that is "connected" (to borrow redux
// terminology) to the router.
export default withRouter(ShowTheLocation)
```
包一层withRouter之后，就可以访问到你想要的属性了，你还可以进一步学习，看看里面都有些什么。