Flutter二维码扫描插件flutter_qrcode_scanner的使用

Flutter二维码扫描插件flutter_qrcode_scanner的使用

获取开始

这个项目是一个新的Flutter插件项目。插件包是一种专门包含针对Android和/或iOS平台实现代码的包。

对于如何开始使用Flutter，你可以查看我们的在线文档，该文档提供了教程、示例、移动开发指南以及完整的API引用。

示例代码

example/lib/main.dart

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

void main() => runApp(MaterialApp(home: QRViewExample()));

const flashOn = '闪光灯打开';
const flashOff = '闪光灯关闭';
const frontCamera = '前置摄像头';
const backCamera = '后置摄像头';

class QRViewExample extends StatefulWidget {
  const QRViewExample({
    Key key,
  }) : super(key: key);

  [@override](/user/override)
  State<StatefulWidget> createState() => _QRViewExampleState();
}

class _QRViewExampleState extends State<QRViewExample> {
  var qrText = ''; // 存储扫描结果的变量
  var flashState = flashOn; // 闪光灯状态
  var cameraState = frontCamera; // 摄像头状态
  QRViewController controller; // 控制器
  final GlobalKey qrKey = GlobalKey(debugLabel: 'QR'); // 全局键

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      body: Column(
        children: <Widget>[
          Expanded(
            flex: 4,
            child: QRView(
              key: qrKey,
              onQRViewCreated: _onQRViewCreated, // 创建QR视图时的回调
              overlay: QrScannerOverlayShape(
                borderColor: Colors.red,
                borderRadius: 10,
                borderLength: 30,
                borderWidth: 10,
                cutOutSize: 300,
              ), // 设置扫描框样式
            ),
          ),
          Expanded(
            flex: 1,
            child: FittedBox(
              fit: BoxFit.contain,
              child: Column(
                mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                children: <Widget>[
                  Text('扫描结果: $qrText'), // 显示扫描结果
                  Row(
                    mainAxisAlignment: MainAxisAlignment.center,
                    crossAxisAlignment: CrossAxisAlignment.center,
                    children: <Widget>[
                      Container(
                        margin: EdgeInsets.all(8),
                        child: ElevatedButton(
                          onPressed: () {
                            if (controller != null) {
                              controller.toggleFlash(); // 切换闪光灯
                              if (_isFlashOn(flashState)) {
                                setState(() {
                                  flashState = flashOff;
                                });
                              } else {
                                setState(() {
                                  flashState = flashOn;
                                });
                              }
                            }
                          },
                          child: Text(flashState, style: TextStyle(fontSize: 20)), // 显示闪光灯状态
                        ),
                      ),
                      Container(
                        margin: EdgeInsets.all(8),
                        child: ElevatedButton(
                          onPressed: () {
                            if (controller != null) {
                              controller.flipCamera(); // 切换摄像头
                              if (_isBackCamera(cameraState)) {
                                setState(() {
                                  cameraState = frontCamera;
                                });
                              } else {
                                setState(() {
                                  cameraState = backCamera;
                                });
                              }
                            }
                          },
                          child: Text(cameraState, style: TextStyle(fontSize: 20)), // 显示摄像头状态
                        ),
                      )
                    ],
                  ),
                  Row(
                    mainAxisAlignment: MainAxisAlignment.center,
                    crossAxisAlignment: CrossAxisAlignment.center,
                    children: <Widget>[
                      Container(
                        margin: EdgeInsets.all(8),
                        child: ElevatedButton(
                          onPressed: () {
                            controller?.pauseCamera(); // 暂停相机
                          },
                          child: Text('暂停', style: TextStyle(fontSize: 20)), // 按钮文本
                        ),
                      ),
                      Container(
                        margin: EdgeInsets.all(8),
                        child: ElevatedButton(
                          onPressed: () {
                            controller?.resumeCamera(); // 恢复相机
                          },
                          child: Text('恢复', style: TextStyle(fontSize: 20)), // 按钮文本
                        ),
                      )
                    ],
                  ),
                ],
              ),
            ),
          )
        ],
      ),
    );
  }

  bool _isFlashOn(String current) {
    return flashOn == current; // 判断当前闪光灯是否开启
  }

  bool _isBackCamera(String current) {
    return backCamera == current; // 判断当前是否为后置摄像头
  }

  void _onQRViewCreated(QRViewController controller) {
    this.controller = controller; // 初始化控制器
    controller.scannedDataStream.listen((scanData) {
      setState(() {
        qrText = scanData; // 更新扫描结果
      });
    });
  }

  [@override](/user/override)
  void dispose() {
    controller.dispose(); // 释放资源
    super.dispose();
  }
}