flutter windows 桌面应用程序: 读取ble蓝牙扫码枪数据

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flutter windows 桌面应用程序: 读取ble蓝牙扫码枪数据

2024-01-12 13:50| 来源: 网络整理| 查看: 265

目标能够监听电脑本身的蓝牙适配器状态能够发现以及停止发现附近的ble蓝牙设备连接指定的ble蓝牙设备订阅指定ble蓝牙设备的特征数据取消订阅指定ble蓝牙设备的特征数据资源释放环境说明

操作系统: Windows 11

flutter版本:

Flutter 3.13.9 • channel stable • https://github.com/flutter/flutter.git Framework • revision d211f42860 (2 weeks ago) • 2023-10-25 13:42:25 -0700 Engine • revision 0545f8705d Tools • Dart 3.1.5 • DevTools 2.25.0 依赖插件

flutter pub add win_ble

定义util类, 封装 win_ble 组件相关方法

win_ble_util.dart

import 'dart:async'; import 'dart:typed_data'; import 'package:win_ble/win_ble.dart'; import 'package:win_ble/win_file.dart'; typedef OnScanedBleDevice = Function(BleDevice); typedef OnBleStateChanged = Function(BleState); typedef OnCharacteristicValueStream = Function(SubscribeToCharacteristicData?); /// ble蓝牙设备连接回调方法 /// [connectResult] 连接结果. true表示连接成功, false表示连接失败 typedef OnConnectedCall = Function(bool connectResult); /// 特征返回的数据 class SubscribeToCharacteristicData { static const _mapKeydeviceAddr = 'address'; static const _mapKeyServiceId = 'serviceId'; static const _mapKeyCharacteristicId = 'characteristicId'; static const _mapKeyValue = 'value'; /// ble设备地址 String deviceAddr; /// ble设备服务id String serviceId; /// ble设备特征id String characteristicId; /// 返回的数据 List? data; SubscribeToCharacteristicData( {required this.deviceAddr, required this.serviceId, required this.characteristicId, this.data}); factory SubscribeToCharacteristicData.fromMap(Map map) { return SubscribeToCharacteristicData( deviceAddr: map[_mapKeydeviceAddr], serviceId: map[_mapKeyServiceId], characteristicId: map[_mapKeyCharacteristicId], data: map[_mapKeyValue]); } /// 将data转换为List数据类型 List? dataToListInt() { return data?.cast(); } /// 将data转换为String数据类型 /// [removeLineBreaks] 是否去除回车/换行符. 默认:false String? dataToString([bool removeLineBreaks = false]) { List? list = dataToListInt(); if (list != null) { String str = String.fromCharCodes(list); if (removeLineBreaks) { str = str.replaceAll("\r\n", ""); str = str.replaceAll("\n", ""); str = str.replaceAll("\r", ""); } return str; } else { return null; } } } /// WinBle组件工具 /// 大概使用流程 /// 1. listenBleState方法，监听蓝牙适配器的状态 /// 2. init方法，对WinBle组件进行初始化 /// 3. scan方法，发现附近的ble设备 /// 4. connect方法，连接指定的ble设备 /// 5. discoverServices方法，获取已连接ble设备提供的所有服务 /// 6. discoverCharacteristics方法，获取已连接ble设备的指定服务下的所有特征 /// 7. readData方法，从已连接ble设备的指定服务的指定特征下，读取一次数据 /// 8. writeDate方法，向已连接ble设备的指定服务的指定特征下，写入一次数据 /// 9. subscribeToCharacteristic方法，订阅已连接ble设备的指定服务的指定特征的数据流，可持续获取到该特征向当前ble适配器发送的数据 /// 10. unSubscribeFromCharacteristic方法，取消对已连接ble设备的指定服务的指定特征的数据流的订阅 /// 11. disconnect方法，断开与已连接ble设备的连接 /// 12. stopListenBleState方法，停止对ble适配器状态的监听 /// 13. stopScan方法，停止发现附近的ble设备 /// 14. dispose方法，释放所有资源 /// /// P.S. openBleAdaptor方法可以打开蓝牙适配器，closeBleAdaptor方法可以关闭蓝牙适配器，getMaxMtuSize方法可以获取已连接ble设备的MaxMtuSize /// /// 以实时获取蓝牙BLE扫描枪扫描的数据为例: (假设蓝牙扫描枪的名称为 Gun_BLE, 假设读取扫描枪数据的服务id和特征id为: xxx, yyy) /// /// 以下是伪代码 /// ```dart /// BleDevice? _connectedBleDevice; /// StreamSubscription? _characteristicStreamSubscription; /// /// // 初始化WinBle组件 /// WinBleUtil.instance.init(); /// // 发现附近的ble设备 /// WinBleUtil.instance.scan((BleDevice bleDevice){ /// if(bleDevice.name=='Gun_BLE'){ /// // 找到了特定设备 /// _connectedBleDevice = bleDevice; /// // 停止ble设备发现 /// WinBleUtil.instance.stopScan(); /// // 建立与ble设备的连接 /// WinBleUtil.instance.connect(_connectedBleDevice,(bool connectResult){ /// if(connectResult){ /// // 与ble设备连接成功，订阅指定特征的数据流，用于实时感知ble扫码枪发过来的数据 /// _characteristicStreamSubscription = WinBleUtil.instance.subscribeToCharacteristic('xxx','yyy',(dynamic data){ /// if(data!=null){ /// // 处理接收到的数据 /// debugPrint(data.runtimeType) /// } /// }); /// } /// }); /// } /// }); /// /// // 最后在合适的时机释放资源 /// if(null!=_characteristicStreamSubscription){ /// _characteristicStreamSubscription.cancel(); /// _characteristicStreamSubscription=null; /// } /// WinBleUtil.instance.dispose(); /// ``` class WinBleUtil { static WinBleUtil? _instance; WinBleUtil._(); static WinBleUtil get instance => _instance ??= WinBleUtil._(); StreamSubscription? _scanBleDeviceStreamSubscription; StreamSubscription? _bleStateStreamSubscription; StreamSubscription? _connectionStreamSubscription; /// 当前连接上的ble蓝牙设备 BleDevice? _connectedBleDevice; String get connectedBleDeviceName => null != _connectedBleDevice ? _connectedBleDevice!.name : ''; /// 当前是否完成了WinBle组件的初始化 bool _isInited = false; /// 当前是否正在发现附近的ble蓝牙设备 bool _isScaning = false; /// ble蓝牙组件初始化 Future init() async { if (_isInited == false) { _isInited = true; WinBle.initialize(serverPath: await WinServer.path, enableLog: false); } } /// 监听蓝牙适配器状态 void listenBleState(OnBleStateChanged onBleStateChanged) { _bleStateStreamSubscription = WinBle.bleState.listen(onBleStateChanged); } /// 打开蓝牙适配器 void openBleAdaptor(OnScanedBleDevice? onScanedBleDevice) { WinBle.updateBluetoothState(true); scan(onScanedBleDevice); } /// 关闭蓝牙适配器 void closeBleAdaptor() { disconnect(); stopScan(); WinBle.updateBluetoothState(false); } /// 发现附近的ble蓝牙设备 void scan(OnScanedBleDevice? onScanedBleDevice) { if (!_isScaning) { _isScaning = true; if (null != onScanedBleDevice) { _scanBleDeviceStreamSubscription = WinBle.scanStream.listen(onScanedBleDevice); } WinBle.startScanning(); } } bool hasConnectedBleDevice() { return _connectedBleDevice != null; } /// 连接指定的ble蓝牙设备 /// [bleDevice] ble蓝牙设备 /// [onConnectedCall] 连接回调方法, 该方法会返回连接结果 Future connect( BleDevice bleDevice, OnConnectedCall onConnectedCall) async { _connectedBleDevice = bleDevice; _connectionStreamSubscription = WinBle.connectionStreamOf(bleDevice.address).listen((onConnectedCall)); await WinBle.connect(bleDevice.address); } /// 获取已连接ble设备的maxMtuSize, 如果没有已连接设备，则返回 Future Future getMaxMtuSize() { if (_connectedBleDevice != null) { return WinBle.getMaxMtuSize(_connectedBleDevice!.address); } return Future.value(null); } /// 获取已连接ble设备的服务列表, 如果没有已连接设备，则返回 Future Future discoverServices() { if (_connectedBleDevice != null) { return WinBle.discoverServices(_connectedBleDevice!.address); } return Future.value(null); } /// 获取已连接ble设备的指定服务的BleCharacteristic列表, 如果没有已连接设备，则返回 Future /// [serviceId] 已连接ble设备的服务id Future discoverCharacteristics( String serviceId) async { if (_connectedBleDevice != null) { return WinBle.discoverCharacteristics( address: _connectedBleDevice!.address, serviceId: serviceId); } return Future.value(null); } /// 从已连接设备的，指定服务的，指定BleCharacteristic中，读取一次数据，如果没有已连接设备，则返回 Future /// [serviceId] 服务标识 /// [characteristicId] 特征标识 Future readData(String serviceId, String characteristicId) async { if (_connectedBleDevice != null) { List data = await WinBle.read( address: _connectedBleDevice!.address, serviceId: serviceId, characteristicId: characteristicId); return data; } else { return Future.value(null); } } /// 向已连接设备的，指定服务的，指定BleCharacteristic中，写入数据 /// [serviceId] 服务标识 /// [characteristicId] 特征标识 /// [data] 待写入的数据 Future writeData( String serviceId, String characteristicId, Uint8List data) async { if (_connectedBleDevice != null) { await WinBle.write( address: _connectedBleDevice!.address, service: serviceId, characteristic: characteristicId, data: data, writeWithResponse: false); } } /// 订阅已连接设备的，指定服务的，指定BleCharacteristic的connectionStream，当不存在已连接设备时，则返回null /// [serviceId] 服务标识 /// [characteristicId] 特征标识 /// [onCharacteristicValueStream] BleCharacteristic有响应数据时，执行的回调 StreamSubscription? subscribeToCharacteristic( String serviceId, String characteristicId, OnCharacteristicValueStream onCharacteristicValueStream) { if (_connectedBleDevice != null) { WinBle.subscribeToCharacteristic( address: _connectedBleDevice!.address, serviceId: serviceId, characteristicId: characteristicId); return WinBle.characteristicValueStream.listen((data) { SubscribeToCharacteristicData? val = data != null && data.runtimeType.toString() == '_Map' ? SubscribeToCharacteristicData.fromMap(data) : null; onCharacteristicValueStream(val); }); } return null; } /// 取消对已连接蓝牙设备的，指定服务的，指定BleCharacteristic的connectionStream订阅 /// [serviceId] 服务标识 /// [characteristicId] 特征标识 Future unSubscribeFromCharacteristic( String serviceId, String characteristicId) async { if (_connectedBleDevice != null) { await WinBle.unSubscribeFromCharacteristic( address: _connectedBleDevice!.address, serviceId: serviceId, characteristicId: characteristicId); } } /// 断开与已连接的ble设备的连接 void disconnect() { if (null != _connectedBleDevice) { WinBle.disconnect(_connectedBleDevice?.address); _connectionStreamSubscription?.cancel(); _connectedBleDevice = null; } } /// 取消对ble蓝牙适配器的状态改变监听 void stopListenBleState() { _bleStateStreamSubscription?.cancel(); } /// 停止发现附近的ble设备 void stopScan() { _scanBleDeviceStreamSubscription?.cancel(); WinBle.stopScanning(); _isScaning = false; } /// 释放所有资源(断开连接,停止对附近ble设备的发现,停止监听ble蓝牙适配器状态,关闭ble蓝牙适配器,执行WinBle.dispose) dispose() { stopListenBleState(); disconnect(); closeBleAdaptor(); WinBle.dispose(); } }

barcode_scanner_ble_util.dart

import 'dart:async'; import 'package:win_ble_demo/src/util/win_ble_util.dart'; class BarcodeScannerBleUtil { static BarcodeScannerBleUtil? _instance; // Avoid self instance BarcodeScannerBleUtil._(); static BarcodeScannerBleUtil get instance => _instance ??= BarcodeScannerBleUtil._(); static String _deviceName = 'BarCode Bluetooth BLE'; static const String _serviceId = '0000feea-0000-1000-8000-00805f9b34fb'; static const String _characteristicsId = '00002aa1-0000-1000-8000-00805f9b34fb'; /// 订阅该特征，就可以收到扫码枪返回的数据 StreamSubscription? subscribeToCharacteristic( OnCharacteristicValueStream onCharacteristicValueStream) { return WinBleUtil.instance.subscribeToCharacteristic( _serviceId, _characteristicsId, onCharacteristicValueStream); } /// 取消特征订阅 Future unSubscribeFromCharacteristic() { return WinBleUtil.instance .unSubscribeFromCharacteristic(_serviceId, _characteristicsId); } }

stateful_builder.dart

import 'package:flutter/material.dart'; class StatefulBuilder extends StatefulWidget { final StatefulWidgetBuilder builder; const StatefulBuilder({Key? key, required this.builder}) : super(key: key); @override _StatefulBuilderState createState() => _StatefulBuilderState(); } class _StatefulBuilderState extends State { @override Widget build(BuildContext context) => widget.builder(context, setState); } 定义ble蓝牙适配器状态组件

实现ble蓝牙适配器状态改变监听，以及连接指定的ble蓝牙设备

ble_status_widget.dart

import 'package:flutter/material.dart'; import 'package:win_ble/win_ble.dart'; import 'package:win_ble_demo/src/util/barcode_scanner_ble_util.dart'; import 'package:win_ble_demo/src/util/win_ble_util.dart'; class BleStatusWidget extends StatefulWidget { const BleStatusWidget({Key? key}) : super(key: key); @override _BleStatusWidgetState createState() => _BleStatusWidgetState(); } typedef stateStateMethod = void Function(void Function()); class _BleStatusWidgetState extends State { String _statusStr = '未知'; final List _bleDeviceList = []; stateStateMethod? _setStateMethod; @override void initState() { super.initState(); WinBleUtil.instance.init(); WinBleUtil.instance.listenBleState((p0) { switch (p0) { case BleState.Disabled: _statusStr = '禁用'; break; case BleState.On: _statusStr = '开启'; break; case BleState.Off: _statusStr = '关闭'; break; case BleState.Unsupported: _statusStr = '不支持'; break; default: _statusStr = '未知'; } debugPrint( '>>>>>>>>>>>>>>>>>>>>>>>>>>>状态变更

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flutter windows 桌面应用程序: 读取ble蓝牙扫码枪数据

flutter windows 桌面应用程序: 读取ble蓝牙扫码枪数据

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