Flutter条码扫描插件famoco_scanner的使用

需求

• 最低版本为Android 10 (API 28)。

兼容设备

兼容以下设备：

• FX 325 (FX325,1)
• FX 335 (FX335,1)

测试设备：

• FX 335 (FX335,1)

使用方法

步骤1

在你的 MainActivity 中继承 FamocoScanPhysicalButtonHandlerActivity。如果你有更优的方法来处理物理按钮，可以忽略此步骤。

忽略此步骤也意味着 FamocoScanner.instance.scanPhysicalButton 将不会被调用。

步骤2

只需使用 FamocoScanner.instance。例如：

FamocoScanner.instance.startScan();

要拦截条形码，你只需要在 StatefulWidget 中使用 decodedComplete：

[@override](/user/override)
void initState() {
    super.initState();
    _onDecodedSubscription = FamocoScanner.instance.decodedComplete.listen(
        (data) {
            setState(() {
                _lastBarcodeScanned = data.barcode;
            });
        });
}

[@override](/user/override)
void dispose() {
    super.dispose();
    _onDecodedSubscription.cancel();
}

当订阅到 decodedComplete 时，会自动调用 FamocoScanner.instance.enableScanner()。同样地，当取消订阅时，会自动调用 disableScanner。

ℹ️ 实现实例会根据设备的品牌自动选择。

示例

你可以查看示例应用。

这是一个与SDK文档中的应用相同的示例：[Demo app (v1.3, source code)]。

完整示例代码

以下是完整的示例代码：

import 'dart:async';

import 'package:famoco_scanner/famoco_decoded_result.dart';
import 'package:famoco_scanner/famoco_physical_button_result.dart';
import 'package:famoco_scanner/famoco_scanner.dart';
import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatefulWidget {
  const MyApp({super.key});

  [@override](/user/override)
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  late final StreamSubscription<FamocoDecodedResult> _onDecodedSubscription;
  late final StreamSubscription<FamocoPhysicalButtonResult>
      _onPhysicalButtonSubscription;

  final _textEditingController = TextEditingController();

  String? _lastBarcodeScanned;
  ValueNotifier<bool> _fillEditTextOnFocus = ValueNotifier(false);
  bool _continousScanPhysicalButton = false;
  bool _nonStopScan = false;
  bool _scanning = false;

  [@override](/user/override)
  void dispose() {
    super.dispose();

    // 不要忘记这一步。
    _onDecodedSubscription.cancel();
    _onPhysicalButtonSubscription.cancel();

    _textEditingController.dispose();
    _fillEditTextOnFocus.removeListener(_fillEditTextOnFocusChanged);
  }

  void _fillEditTextOnFocusChanged() {
    FamocoScanner.instance.setOptions(
      onDecodedUseKeyboardEvents: _fillEditTextOnFocus.value,
    );
  }

  void _scanButtonPressed() {
    if (_scanning) {
      _startScan();
    } else {
      _stopScan();
    }
  }

  void _clearButtonPressed() {
    _lastBarcodeScanned = null;
    _fillEditTextOnFocus.value = false;
    _nonStopScan = false;
    _continousScanPhysicalButton = false;
    _scanning = false;
    _textEditingController.clear();

    setState(() {});
  }

  Widget _buildCheckbox(
    String text,
    bool value,
    ValueChanged<bool?>? onChanged,
  ) {
    return Row(
      children: [
        Checkbox(value: value, onChanged: onChanged),
        Expanded(
          child: Text(text),
        ),
      ],
    );
  }

  void _startScan() {
    setState(() {
      _scanning = true;
    });

    FamocoScanner.instance.startScan(isHandsFree: _nonStopScan);
  }

  void _stopScan() {
    setState(() {
      _scanning = false;
    });

    FamocoScanner.instance.stopScan();
  }

  [@override](/user/override)
  void initState() {
    super.initState();
    _onDecodedSubscription = FamocoScanner.instance.decodedComplete.listen(
      (data) {
        if (!_nonStopScan) {
          _stopScan();
        }

        _lastBarcodeScanned = data.barcode;

        setState(() {});
      },
    );

    _onPhysicalButtonSubscription =
        FamocoScanner.instance.scanPhysicalButton.listen((event) {
      if (event.isKeyDown) {
        if (!_continousScanPhysicalButton) {
          _startScan();
        }
      } else {
        if (_continousScanPhysicalButton && _scanning) {
          _startScan();
        } else {
          _stopScan();
        }
      }
    });

    _fillEditTextOnFocus.addListener(_fillEditTextOnFocusChanged);
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: SafeArea(
          child: Column(
            children: [
              Expanded(
                child: SingleChildScrollView(
                  child: Column(
                    children: [
                      Text(
                        '请扫描条形码',
                        style: Theme.of(context).textTheme.titleLarge,
                      ),
                      Container(
                        margin: const EdgeInsets.all(16),
                        child: Text(
                          _lastBarcodeScanned ?? '未扫描条形码',
                          style: Theme.of(context).textTheme.bodyMedium,
                        ),
                      ),
                      TextField(
                        controller: _textEditingController,
                      ),
                      _buildCheckbox(
                        '启用焦点填充编辑文本',
                        _fillEditTextOnFocus.value,
                        (value) {
                          setState(() {
                            _fillEditTextOnFocus.value = value ?? false;
                          });
                        },
                      ),
                      _buildCheckbox(
                        '连续扫描物理按钮',
                        _continousScanPhysicalButton,
                        (value) {
                          setState(() {
                            _continousScanPhysicalButton = value ?? false;
                          });
                        },
                      ),
                      _buildCheckbox(
                        '非停止扫描',
                        _nonStopScan,
                        (value) {
                          setState(() {
                            _nonStopScan = value ?? false;
                          });
                        },
                      ),
                    ],
                  ),
                ),
              ),
              Row(
                children: [
                  Expanded(
                    child: TextButton(
                      onPressed: _scanButtonPressed,
                      style: ButtonStyle(
                        backgroundColor: MaterialStateProperty.all(
                          _scanning ? Colors.red : Colors.green,
                        ),
                        foregroundColor:
                            MaterialStateProperty.all(Colors.white),
                      ),
                      child: Text(_scanning ? '停止' : '扫描'),
                    ),
                  ),
                  Expanded(
                    child: TextButton(
                      onPressed: _clearButtonPressed,
                      style: ButtonStyle(
                        backgroundColor: MaterialStateProperty.all(Colors.blue),
                        foregroundColor:
                            MaterialStateProperty.all(Colors.white),
                      ),
                      child: const Text('清除'),
                    ),
                  ),
                ],
              ),
            ],
          ),
        ),
      ),
    );
  }
}