react-router v4之前的版本，有一個叫做withRouter的高階元件。你在定義自己的modal組件時包一層即可。

v4版本暫時沒有用過，有沒有改動不清楚

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

// Create a new component that is "connected" (to borrow redux
// terminology) to the router.
export default withRouter(ShowTheLocation)

包一層withRouter之後，就可以存取到你想要的屬性了，你還可以進一步學習，看看裡面都有些什麼。

也可以使用withRouter，透過this.props.location取得

import React, { Component } from 'react';
import { withRouter } from 'react-router'


class  MyComponent extends Component {

   .....
}

export default withRouter(MyComponent)