Flutter蓝牙通信插件flutter_ttc_ble的使用

Flutter蓝牙通信插件flutter_ttc_ble的使用

flutter_ttc_ble

flutter_ttc_ble 是一个用于 Android 和 iOS 的 BLE（Bluetooth Low Energy）的 Flutter 插件。 你可以通过以下链接获取示例代码：flutter_ttc_ble_example

Getting Started

准备

• Android：版本高于5.0（包含），需要位置权限并打开位置服务，位置权限可借助其他库，如 permission_handler。
• iOS：版本高于10.0，在Info.plist中增加Privacy - Bluetooth Always Usage Description。

扫描设备

• 初始化插件（使用0.0.5新增的 bleProxy 可以不用显式初始化）

FlutterTtcBle.init();

• 开始扫描

//开启扫描
FlutterTtcBle.startLeScan((device) {
  //处理数据
});

• 停止扫描

//停止扫描
FlutterTtcBle.stopLeScan();

连接设备 / 断开连接

• 连接设备

//连接设备
FlutterTtcBle.connect(deviceId: device.deviceId);

• 断开连接

//断开连接
FlutterTtcBle.disconnect(device.deviceId);

发送数据

与蓝牙设备通信的 UUID

const UUID_SERVICE = '00001000-0000-1000-8000-00805f9b34fb';
const UUID_WRITE = '00001001-0000-1000-8000-00805f9b34fb';
const UUID_NOTIFY = '00001002-0000-1000-8000-00805f9b34fb';

FlutterTtcBle.writeCharacteristic(
    deviceId: deviceId,
    serviceUuid: UUID_SERVICE,
    characteristicUuid: UUID_WRITE,
    value: data,
    writeType: CharacteristicWriteType.writeNoResponse);

接收数据

• 通知事件中获取数据

BleCallback bleCallback = (message) {
  if (message is Map<dynamic, dynamic>) {
    if (message.containsKey('event')) {
      switch (message['event']) {
        case BLEEvent.CONNECTEDed: //与设备建立连接
          //开启数据通知，这样才能实时接收设备端的数据
          FlutterTtcBle.setCharacteristicNotification(
            deviceId: message['deviceId'],
            serviceUuid: UUID_SERVICE,
            characteristicUuid: UUID_NOTIFY,
            enable: true);
          break;

        case BLEEvent.DATA_AVAILABLE: //收到数据
          Uint8List data = (message['value'] as Uint8List);
          break;
      }
    }
  }
};

从0.0.5开始，可以使用 bleProxy 和 BleCallback2，无需再通过判断运行时的动态消息类型来区分蓝牙事件

class _CommPageState extends State<CommPage> with BleCallback2 {

  [@override](/user/override)
  void initState() {
    super.initState();
    print('CommPage initState()');
    _deviceId = widget.device.deviceId;
    //连接设备
    bleProxy.connect(deviceId: _deviceId);

    //监听蓝牙异步事件通知
    bleProxy.addBleCallback(this);
  }

  [@override](/user/override)
  void dispose() {
    print('CommPage -> dispose()');
    //取消监听蓝牙异步事件通知
    bleProxy.removeBleCallback(this);
    bleProxy.disconnect(deviceId: _deviceId); //断开连接
    super.dispose();
  }

  [@override](/user/override)
  void onDataReceived(String deviceId, String serviceUuid, String characteristicUuid, Uint8List data) {
    //收到数据
    String utf8String = "";
    try {
      utf8String = utf8.decode(data);
    } on Exception catch (e) {
      print(e);
    }

    String hexString = data.toHex();

    print('<- utf8String=$utf8String, hexString=$hexString');
  }
  
  //可以按需实现 BleCallback2 的其它方法
  ...
}

0.0.5版本新增一个内置的扫描页面，用于编写测试APP比较方便

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: ScanScreen(
        title: 'TTC Flutter BLE Demo',
        onDeviceClick: (BuildContext context, BLEDevice device) {
          Navigator.push(
              context,
              MaterialPageRoute(
                  builder: (context) => CommPage(device: device)));
        },
      ),
    );
  }
}

示例代码

import 'package:flutter/material.dart';
import 'package:flutter_ttc_ble/flutter_ttc_ble.dart';
import 'package:flutter_ttc_ble/scan_screen.dart';

import 'communication.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: ScanScreen(
        title: 'TTC Flutter BLE Demo',
        onDeviceClick: (BuildContext context, BLEDevice device) {
          Navigator.push(
              context,
              MaterialPageRoute(
                  builder: (context) => CommPage(device: device)));
        },
        onConnectDevicesClick: null/*(context, devices) {

        }*/,
      ),
    );
  }
}