https://pub.dev/packages/qrscan#-example-tab-

    前言
    前几天突发奇想就想做一个扫描二维码和条形码的demo，查阅了一些资料，发现有qrscan这个插件可以实现，就自己写了一个例子，供大家学习.

    准备工具
    这套课程是采用Android Studio进行开发的。当前在此之前请准备好Flutter开发环境，我这里就不进行讲解了。

    引入插件
    到pubspce.yaml中导包

    1. dependencies:
    2.  flutter:
    3.    sdk: flutter
    4.  # The following adds the Cupertino Icons font to your application.
    5.  # Use with the CupertinoIcons class for iOS style icons.
    6.  cupertino_icons: ^0.1.2
    7.  qrscan: ^0.1.3

    具体实现

    1. import 'package:flutter/material.dart';
    2. import 'package:qrscan/qrscan.dart' as scanner;
    3. void main() => runApp(MyApp());
    4. class MyApp extends StatefulWidget {
    5.  MyApp({Key key}) : super(key: key);
    6.  _MyAppState createState() => _MyAppState();
    7. }
    8. class _MyAppState extends State<MyApp> {
    9.  String barcode = "";
    10.  @override
    11.  initState() {
    12.    super.initState();
    13.  }
    14.  @override
    15.  Widget build(BuildContext context) {
    16.    return MaterialApp(
    17.      home: Scaffold(
    18.        appBar: AppBar(
    19.          title: Text('Scan barcodes and qr codes'),
    20.        ),
    21.        body: Center(
    22.          child: Column(
    23.            mainAxisAlignment: MainAxisAlignment.end,
    24.            children: <Widget>[
    25.              Text(barcode),
    26.              MaterialButton(
    27.                onPressed: scan,
    28.                child: Text("Scan"),
    29.                color: Colors.blue,
    30.                textColor: Colors.white,
    31.              ),
    32.            ],
    33.          ),
    34.        ),
    35.      ),
    36.    );
    37.  }
    38.  Future scan() async {
    39.    try {
    40.      String barcode = await scanner.scan();
    41.      setState(() => this.barcode = barcode);
    42.    } on Exception catch (e) {
    43.      if (e == scanner.CameraAccessDenied) {
    44.        setState(() {
    45.          this.barcode = 'The user did not grant the camera permission!';
    46.        });
    47.      } else {
    48.        setState(() => this.barcode = 'Unknown error: $e');
    49.      }
    50.    } on FormatException {
    51.      setState(() => this.barcode = 'null (User returned using the "back"-button before scanning anything. Result)');
    52.    } catch (e) {
    53.      setState(() => this.barcode = 'Unknown error: $e');
    54.    }
    55.  }
    56. }

    ————————————————
    版权声明：本文为CSDN博主「追逐蓦然」的原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接及本声明。
    原文链接：https://blog.csdn.net/qq_35905501/article/details/89467886