react如何在切换路由的时候，页面在最顶部

vue有相关配置，但是因为用户需要，reactRouter在之前的版本中舍弃了其配置，需要用户自定义设置

方法：

创建一个组件，判断切换后的页面是否是最顶端

···

import React from 'react';
import {
    Route,
    withRouter,
} from "react-router-dom";
class ScrollToTop extends React.Component {
    componentDidUpdate(prevProps, prevState, snapshot) {
        if (this.props.location.pathname !== prevProps.location.pathname) {
            window.scrollTo(0, 0)
        }
    }
    render() {
        return this.props.children
    }
}
export default ScrollToTop;

```
然后在app中引入该组件

```

return (
    <Router>
        <Switch>
            <ScrollToTop>
                <Route path='/' exact
                       render={token ? () => LayEditRouter : () => <Redirect to='/login' push/>}
                />
                <Route path='/login' component={Login}/>
                <Route path='/' render={props => LayEditRouter}/>
            </ScrollToTop>
        </Switch>
    </Router>
);