虽然在组件内部可以使用 this.context.router 来实现导航，但许多应用想要在组件外部使用导航。使用Router组件上被赋予的history可以在组件外部实现导航。
this.context.router
// your main file that renders a Routerimport { Router, browserHistory } from 'react-router'import routes from './app/routes'render(<Router history={browserHistory} routes={routes}/>, el)
// your main file that renders a Router
import { Router, browserHistory } from 'react-router'
import routes from './app/routes'
render(<Router history={browserHistory} routes={routes}/>, el)
// somewhere like a redux/flux action file:import { browserHistory } from 'react-router'browserHistory.push('/some/path')
// somewhere like a redux/flux action file:
import { browserHistory } from 'react-router'
browserHistory.push('/some/path')
