Add scroll to top

src/routes.js

-import React from 'react';
+import React, { useEffect } from 'react';
 import MainPage  from './components/MainPage';
 import ReproducePage from './components/ReproducePage';
 import TutorialsPage  from './components/TutorialsPage';
-import { Route, Switch, Redirect } from 'react-router-dom';
+import { 
+    BrowserRouter as Router,
+    Route, 
+    Switch, 
+    Redirect,
+    withRouter,
+    useLocation
+} from 'react-router-dom';
+
+function _ScrollToTop(props) {
+    const { pathname } = useLocation();    useEffect(() => {
+        window.scrollTo(0, 0);
+    }, [pathname]);    return props.children
+}
+
+const ScrollToTop = withRouter(_ScrollToTop)
 
 export const Routes = () => {
 
     return (
         <div>
+            <Router>
+                <ScrollToTop>
+
                     <Switch>
                         <Route exact path="/Main" component={MainPage}/>
                         < Route exact path="/">
@@ -16,7 +34,9 @@ export const Routes = () => {
                         <Route exact path="/Reproduce" component={ReproducePage}/>
                         <Route exact path="/Tutorials" component={TutorialsPage}/>
                     </Switch>
+                </ScrollToTop>
 
+            </Router>
         </div>
     );