problem description
report "propTypes" is not defined no-undef error
the environmental background of the problems and what methods you have tried
installed propTypes, is also introduced, but I don"t know why I reported this error
related codes
 / / Please paste the code text below (do not replace the code with pictures) 
 import React from "react"; 
 import {HashRouter as Router, Route, Switch, Redirect} from" react-router-dom"; 
 import {hashHistory} from "react-router"; 
 import NotFound from". / components/pages/NotFound"; 
 import App from". / App"; 
 import PropTypes from "prop-types"; 
 import {connect} from" react-redux"; 
 import {initMenu} from". / store/index/action" 
class Page extends React.Component {
static propTypes = {
    initMenu: PropTypes.func
}
constructor(props){
    super(props);
    this.state={
        path: "/app/realtime/survey"
    }
}
