react如何监听路由url变化

"componentWillReceiveProps"
"shouldComponentUpdate"
"componentWillUpdate"
"render"
"componentDidUpdate"

使用这些生命周期钩子可以监听到路由相同，参数不同的变化，但是监听不到完全不相同的url的变化。即使路由不同，componentDidMount组件内容所更新的东西变了，但是代码变了，页面没有变，找到了一种方法。withRouter

参考：https://reacttraining.com/react-router/web/api/withRouter

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>
    )
  }
}

export default withRouter(ShowTheLocation) //组件名称，导出该组件，保证在最外边