我对颤振完全陌生，我正在使用 web view 小部件，但是每当我按下它时，它就会退出应用程序。按下后退按钮时如何返回上一页？
这是我的代码片段
import 'package:flutter/material.dart';
import 'package:webview_flutter/webview_flutter.dart';
void main() => runApp(MyApp());
WebViewController controllerGlobal;
Future<bool> _exitApp(BuildContext context) async {
if (await controllerGlobal.canGoBack()) {
print("onwill goback");
controllerGlobal.goBack();
return Future.value(true);
} else {
Scaffold.of(context).showSnackBar(
const SnackBar(content: Text("No back history item")),
);
return Future.value(false);
}
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
title: 'TRAVMAKS',
home: WillPopScope(
onWillPop: () => _exitApp(context),
child:Scaffold(
body: Container(
margin: const EdgeInsets.only(top: 52.0),
child: Container(
margin: const EdgeInsets.only(top: 0.0),
child: WebView(
initialUrl: 'https://www.google.com',
javascriptMode: JavascriptMode.unrestricted,
)
)
)
)
)
);
}
}