Flutter 中的蓝牙连接：实现设备通信

Flutter 中的蓝牙连接：实现设备通信

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使用Flutter的flutter_blue插件进行蓝牙连接和通信。

更多关于Flutter 中的蓝牙连接：实现设备通信的实战系列教程也可以访问 https://www.itying.com/category-92-b0.html


在 Flutter 中，使用 flutter_blue 或 flutter_blue_plus 库实现蓝牙连接和设备通信。首先扫描设备，然后连接并发现服务，最后通过特征值读写数据。

在Flutter中实现蓝牙设备通信，可以使用flutter_blue库。首先，在pubspec.yaml中添加依赖。然后，初始化FlutterBlue实例，扫描附近的蓝牙设备，连接目标设备，并发现其服务和特征值。通过读写特征值实现与设备的通信。示例代码如下：

import 'package:flutter_blue/flutter_blue.dart';

FlutterBlue flutterBlue = FlutterBlue.instance;

void scanAndConnect() async {
  flutterBlue.startScan(timeout: Duration(seconds: 4));
  flutterBlue.scanResults.listen((results) {
    for (ScanResult result in results) {
      if (result.device.name == 'YourDeviceName') {
        result.device.connect();
        result.device.discoverServices().then((services) {
          for (BluetoothService service in services) {
            for (BluetoothCharacteristic characteristic in service.characteristics) {
              // 读写特征值
              characteristic.read();
              characteristic.write([0x12, 0x34]);
            }
          }
        });
      }
    }
  });
}

确保处理连接状态和错误，以增强应用的健壮性。

使用Flutter的flutter_bluetooth_serial等插件实现蓝牙连接和数据通信。

在Flutter中实现蓝牙连接和设备通信，可以使用flutter_blue插件。以下是一个简单的示例，展示如何扫描、连接蓝牙设备并进行通信。

1. 添加依赖

首先，在pubspec.yaml文件中添加flutter_blue依赖：

dependencies:
  flutter:
    sdk: flutter
  flutter_blue: ^0.8.0

然后运行flutter pub get安装依赖。

2. 扫描并连接蓝牙设备

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

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: BluetoothApp(),
    );
  }
}

class BluetoothApp extends StatefulWidget {
  @override
  _BluetoothAppState createState() => _BluetoothAppState();
}

class _BluetoothAppState extends State<BluetoothApp> {
  FlutterBlue flutterBlue = FlutterBlue.instance;
  List<ScanResult> scanResults = [];
  BluetoothDevice? connectedDevice;

  void startScan() {
    flutterBlue.startScan(timeout: Duration(seconds: 4));
    flutterBlue.scanResults.listen((results) {
      setState(() {
        scanResults = results;
      });
    });
  }

  void connectToDevice(BluetoothDevice device) async {
    await device.connect();
    setState(() {
      connectedDevice = device;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Flutter Bluetooth'),
      ),
      body: Column(
        children: <Widget>[
          ElevatedButton(
            onPressed: startScan,
            child: Text('Scan'),
          ),
          Expanded(
            child: ListView.builder(
              itemCount: scanResults.length,
              itemBuilder: (context, index) {
                return ListTile(
                  title: Text(scanResults[index].device.name),
                  subtitle: Text(scanResults[index].device.id.toString()),
                  onTap: () => connectToDevice(scanResults[index].device),
                );
              },
            ),
          ),
          if (connectedDevice != null)
            Text('Connected to: ${connectedDevice!.name}'),
        ],
      ),
    );
  }
}

3. 通信

连接设备后，你可以使用BluetoothDevice的discoverServices方法来发现服务，并通过BluetoothCharacteristic进行读写操作。

void discoverServices(BluetoothDevice device) async {
  List<BluetoothService> services = await device.discoverServices();
  for (BluetoothService service in services) {
    for (BluetoothCharacteristic characteristic in service.characteristics) {
      if (characteristic.properties.read) {
        List<int> value = await characteristic.read();
        print('Read value: $value');
      }
      if (characteristic.properties.write) {
        await characteristic.write([0x12, 0x34]);
      }
    }
  }
}

注意事项

  • 需要在AndroidManifest.xml和Info.plist中添加相应的权限和配置。
  • 实际应用中可能需要处理更多的错误和异常情况。

通过以上步骤，你可以在Flutter中实现蓝牙设备的扫描、连接和通信。

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