Question

如何从任何屏幕导航回主屏幕。我尝试在下面画一些例子。

runApp() ->HomePage()
           ->FirstScreen()
             ->FirstSubScreen() // <- Back to HomePage
           ->SecondScreen()
           ->ThirdScreen()

我要实现的目标是，当我在FirstSubScreen时，我可以导航回HomePage。我尝试使用onPressed: () => Navigator.popUntil(context, ModalRoute.withName('/homepage')，但是什么也没有发生，没有错误或其他任何东西。那么我该如何解决这个问题呢？我将包含一些代码。

main.dart

void main() => runApp(new MyApp());

String username = '';

class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new MaterialApp(
  debugShowCheckedModeBanner: false,
  home: LoginPage(),
  routes: <String, WidgetBuilder>{
    '/landingpage': (BuildContext context) => new MyApp(),
    '/homepage': (BuildContext context) => new HomePage(
          username: username,
        ),
  },
);
}
}

在登录页面中，我成功登录后就是社交登录，它导航到HomePage()

在主页中，我正在使用具有3个标签的标签控制器，分别为FirstScreen，SecondScreen，ThirdScreen。在FirstScreen中，我有一个扫描按钮，成功扫描后，它将导航到FirstSubScreen，下面是代码。

FirstScreen.dart

Future scan() async {
try {
  String barcode = await BarcodeScanner.scan();
  setState(() {
    var parsedJson = jsonDecode(barcode);
    var qrdetails = QRDetails.fromJson(parsedJson);
    final data = QRDetails(
      name: "${qrdetails.name}",
      type: "${qrdetails.type}",
      amount: "${qrdetails.amount}",
    );

    Navigator.push(
        context,
        MaterialPageRoute(
            builder: (context) => ScannedScreen(
                  barcodedata: data,
                )));
  });
} on PlatformException catch (e) {
  if (e.code == BarcodeScanner.CameraAccessDenied) {
    setState(
        () /* {
      this.barcode = 'The user did not grant the camera permission!';
    } */
        {
      Fluttertoast.showToast(
          msg: 'You need to grant the camera permission',
          toastLength: Toast.LENGTH_SHORT);
    });
  } else {
    setState(() => this.barcode = 'Unknown error: $e');
  }
} on FormatException {
  setState(
      () /* => this.barcode =
      'null (User returned using the "back"-button before scanning anything. Result)' */
      {
    Fluttertoast.showToast(
        msg: 'Scan canceled', toastLength: Toast.LENGTH_SHORT);
  });
} catch (e) {
  setState(() => this.barcode = 'Unknown error: $e');
}
}

FirstSubScreen

Widget backtoMainButton() {
return Align(
    alignment: FractionalOffset.bottomCenter,
    child: Container(
        height: 80.0,
        child: SizedBox.expand(
          child: FlatButton(
            onPressed: () {
              Navigator.of(context).popUntil(ModalRoute.withName('/homepage'));
            },
            child: Text('BACK TO HOME',
                style: TextStyle(
                    fontSize: 16.0,
                    fontFamily: "Roboto Regular",
                    color: Colors.black)),
          ),
        )));
}

颤振从任何屏幕导航到某个屏幕

0 个答案: