import { HashRouter as Router, Route, hashHistory } from 'react-router-dom'

頁面就會報錯Attempted import error: 'hashHistory' is not exported from 'react-router'.

原因react-router4現在不支持hashHistory了，解決辦法如下：

import createHashHistory from 'history/createHashHistory';
const hashHistory = createHashHistory();

但是又提示Warning: Please use require("history").createHashHistory instead of require("history/createHashHistory"). Support for the latter will be removed in the next major release.如下改一下：

import { createHashHistory } from 'history';
const hashHistory = createHashHistory();

此時 Warning: <HashRouter> ignores the history prop. To use a custom history, use import { Router } instead of import { HashRouter as Router }.
OK，暫時解決眼前的問題。