Навигатор страниц приложения с одной на страницу веб-просмотра

Question

Навигатор моего приложения от одной страницы до веб-просмотра, там есть черный флажок sh, затем веб-просмотр загружается с заданного URL-адреса веб-сайта. Как избежать этой ошибки? У всех ли виджетов, использующих androidView данных из натива, одинаковые проблемы?

flutter doctor -v [√] Flutter (Channel master, v1.13.4-pre.9, в Microsoft Windows [ Версия 10.0.17763.615], язык zh-CN) • Flutter версия 1.13.4-pre.9 в C: \ flutter-git \ flutter • Редакция фреймворка e3c8eca (4 месяца a go), 2019-12-19 14:27:35 -0800 • Версия двигателя 0f90e65 • Версия Dart 2.8.0 (сборка 2.8.0-dev.0.0 aa6709974d)

[√] Android toolchain - разработка для Android устройств (Android SDK версии 28.0.3) • Android SDK в C: \ Users \ Administrator \ AppData \ Local \ Android \ Sdk • Android Расположение NDK не настроено (необязательно; полезно для поддержки собственного профилирования) • Платформа android -29, build-tools 28.0.3 • ANDROID_HOME = C: \ Users \ Администратор \ AppData \ Local \ Android \ Sdk • Java двоичный в: C: \ Program Files \ Android \ Android Studio \ jre \ bin \ java • Java версия среды выполнения OpenJDK (сборка 1.8.0_212-выпуск-1586-b04) • все Android l icenses приняты.

[√] Chrome - разработка для Интернета • Chrome в C: \ Program Files (x86) \ Google \ Chrome \ Application \ chrome .exe

[√] Visual Studio - разработка для Windows (Visual Studio Community 2017 15.9.15) • Visual Studio по адресу C: \ Program Files (x86) \ Microsoft Visual Studio \ 2017 \ Community • Сообщество Visual Studio 2017 версия 15.9.28307.812

[√] Android Studio (версия 3.6) • Android Studio at C: \ Program Files \ Android \ Android Studio • Плагин Flutter версии 45.1.1 • Dart версия плагина 192.7761 • Java версия среды выполнения OpenJDK (сборка 1.8.0_212-release-1586-b04)

[√] VS-код (версия 1.44.2) • VS-код в C: \ Users \ Администратор \ AppData \ Local \ Программы \ Microsoft VS Code • Расширение Flutter версии 3.7.1

[√] Подключенное устройство (доступно 4) • PCAM00 • 74f892cf • android -arm64 • Android 9 ( API 28) • Windows • Windows • windows -x64 • Microsoft Windows [Версия 10.0.17763.615] Chrome • chrome • web- javascript • Google Chrome 81.0.4044.122 • Веб-сервер • web-сервер • web- javascript • Инструменты флаттера

• Не найдено проблем!

Мой код:

import 'package:flutter/material.dart';
import 'package:webview_flutter/webview_flutter.dart';

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

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class WebViewPage extends StatefulWidget {
  @override
  _WebViewPageState createState() => _WebViewPageState();
}

class _WebViewPageState extends State<WebViewPage> {
  String _title = "webview";

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text("$_title"),
        ),
        body: SafeArea(
          child: WebView(
            initialUrl: "https://www.baidu.com/",
            javascriptMode: JavascriptMode.unrestricted,
          ),
        ),
    );
  }
}
class Detail extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      //浮动按钮
      floatingActionButton: FloatingActionButton(
        child: Text('返回'),
        onPressed: (){
          Navigator.of(context).pop();
        },
      ),
      appBar: AppBar(title: Text("详情页面"),),
      body: SafeArea(
        child: WebView(
          initialUrl: "https://www.baidu.com/",
          javascriptMode: JavascriptMode.unrestricted,
        ),
      ),
    );
  }
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
      Navigator.push(context, MaterialPageRoute(
        //没有传值
          builder: (context)=>WebViewPage()
      ));
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Invoke "debug painting" (press "p" in the console, choose the
          // "Toggle Debug Paint" action from the Flutter Inspector in Android
          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
          // to see the wireframe for each widget.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. Here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.display1,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}