首先withRouter可以用來給組件注入router相關的一些參數，比如：

```

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.

const ShowTheLocationWithRouter = withRouter(ShowTheLocation)

```

其次withRouter是專門用來處理數據更新問題的。在使用一些redux的的`connect()`或者mobx的`inject()`的組件中，如果依賴于路由的更新要重新渲染，會出現路由更新了但是組件沒有重新渲染的情況。這是因為redux和mobx的這些連接方法會修改組件的`shouldComponentUpdate`。

座椅在使用withRouter解決更新問題的時候，一定要保證withRouter在最外層，比如`withRouter(connect(Component))`