如何在flutter中用main.dart实现多个包？

Question

我正在用flutter-android开发一个应用程序，为此，我正在使用screenUtil包，同时我也在检查设备连接状态(互联网)。现在，我的main.dart代码如下我初始化screenUtil的位置

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ScreenUtilInit(
      designSize: Size(360, 690),
      allowFontScaling: false,
      builder: () => MaterialApp(
        debugShowCheckedModeBanner: false,
        home: HomeScreen(),
      ),
    );
  }
}

下面是我需要在main.dart中使用的代码，用于获取小部件之间的连接状态：

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

class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
  return StreamProvider<ConnectivityStatus>(
    builder: (context) => ConnectivityService().connectionStatusController,
    child: MaterialApp(
      debugShowCheckedModeBanner: false,
      home: HomeScreen(),
    ),
  );
}

如何在main.dart文件中同时使用这两个代码？

Answer 1

示例:在flutter中以编程方式进行互联网连接检查。

你可以和我的代码同步。

下面详细介绍了我的源代码。只需复制并传递，然后用您的代码修改它就是main.dart文件：

import 'package:connectivity/connectivity.dart';
import 'package:flutter/material.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ScreenUtilInit(
      designSize: Size(360, 690),
      builder: () => MaterialApp(
        debugShowCheckedModeBanner: false,
        home: HomeScreen(),
      ),
    );
  }
}
class HomeScreen extends StatefulWidget {
  @override
  _HomeScreenState createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  var connectionStatus="";
  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    checkConnection();

  }
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Text(connectionStatus),
      ),
    );
  }
  void checkConnection() async{
    var connectivityResult = await (Connectivity().checkConnectivity());
    if (connectivityResult == ConnectivityResult.mobile) {
      // I am connected to a mobile network.
      // write your code here;
      connectionStatus="mobile data";
    } else if (connectivityResult == ConnectivityResult.wifi) {
      // I am connected to a wifi network.
      // write your code here
      connectionStatus="wifi data";
    } else {
// where your code here
      connectionStatus="no internet connection";
    }
  }
}

和我的pubspec.yaml文件

name: flutter_app
description: A new Flutter application.
version: 1.0.0+1
environment:
  sdk: ">=2.7.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter
  cupertino_icons: ^1.0.2
  flutter_screenutil: ^5.0.0
  data_connection_checker: ^0.3.4
  connectivity: ^3.0.2
  connectivity_platform_interface: ^2.0.1

dev_dependencies:
  flutter_test:
    sdk: flutter
flutter:
  uses-material-design: true

祝你好运！