Flutter串口通信插件serialport_plus的使用

当然，以下是一个关于如何在Flutter应用中使用serialport_plus插件来实现串口通信的示例代码。这个示例将涵盖基本的串口打开、读取和写入操作。

首先，确保你已经在你的pubspec.yaml文件中添加了serialport_plus依赖：

dependencies:
  flutter:
    sdk: flutter
  serialport_plus: ^x.y.z  # 替换为最新版本号

然后，运行flutter pub get来安装依赖。

接下来，在你的Flutter项目中创建一个服务来管理串口通信。这里是一个简单的示例：

// serial_service.dart
import 'dart:typed_data';
import 'package:flutter/services.dart';
import 'package:serialport_plus/serialport_plus.dart';

class SerialService {
  late SerialPort _serialPort;
  late MethodChannel _channel;

  SerialService() {
    _channel = MethodChannel('com.example.flutter_serial_communication');
  }

  Future<void> openPort(String portName, int baudRate) async {
    try {
      _serialPort = await SerialPort.fromPath(portName, baudRate);
      _serialPort.inputStream.listen((Uint8List data) {
        // 处理接收到的数据
        String receivedData = String.fromCharCodes(data);
        print("Received: $receivedData");
        _channel.invokeMethod('onDataReceived', receivedData);
      });
      print("Port opened successfully.");
    } catch (e) {
      print("Error opening port: $e");
      _channel.invokeMethod('onError', e.toString());
    }
  }

  Future<void> writeData(String data) async {
    try {
      if (_serialPort.isOpen) {
        _serialPort.write(data.codeUnits);
        print("Data written: $data");
      } else {
        print("Port is not open.");
      }
    } catch (e) {
      print("Error writing data: $e");
      _channel.invokeMethod('onError', e.toString());
    }
  }

  Future<void> closePort() async {
    try {
      if (_serialPort.isOpen) {
        await _serialPort.close();
        print("Port closed.");
      }
    } catch (e) {
      print("Error closing port: $e");
      _channel.invokeMethod('onError', e.toString());
    }
  }
}

然后，在你的Flutter应用的Dart文件中（比如main.dart），你可以使用这个服务来与串口进行交互：

// main.dart
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'serial_service.dart';

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

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  late SerialService _serialService;
  final MethodChannel _channel = MethodChannel('com.example.flutter_serial_communication');
  String _portName = "/dev/ttyUSB0";  // 根据你的设备修改
  int _baudRate = 9600;
  String _receivedData = "";
  TextEditingController _controller = TextEditingController();

  @override
  void initState() {
    super.initState();
    _serialService = SerialService();
    _channel.setMethodCallHandler((MethodCall call) async {
      if (call.method == 'onDataReceived') {
        setState(() {
          _receivedData += call.arguments;
        });
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Flutter Serial Communication'),
        ),
        body: Padding(
          padding: const EdgeInsets.all(16.0),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: <Widget>[
              Text('Received Data:', style: TextStyle(fontSize: 18)),
              Text(_receivedData, style: TextStyle(fontSize: 16)),
              SizedBox(height: 20),
              Text('Send Data:', style: TextStyle(fontSize: 18)),
              TextField(
                controller: _controller,
                decoration: InputDecoration(border: OutlineInputBorder()),
              ),
              SizedBox(height: 10),
              Row(
                children: <Widget>[
                  ElevatedButton(
                    onPressed: () async {
                      await _serialService.openPort(_portName, _baudRate);
                    },
                    child: Text('Open Port'),
                  ),
                  SizedBox(width: 10),
                  ElevatedButton(
                    onPressed: () async {
                      await _serialService.writeData(_controller.text);
                      _controller.clear();
                    },
                    child: Text('Send Data'),
                  ),
                  SizedBox(width: 10),
                  ElevatedButton(
                    onPressed: () async {
                      await _serialService.closePort();
                    },
                    child: Text('Close Port'),
                  ),
                ],
              ),
            ],
          ),
        ),
      ),
    );
  }
}

这个示例展示了如何使用serialport_plus插件在Flutter应用中打开串口、读取数据和写入数据。请注意，根据你的设备和平台，串口路径（_portName）可能需要调整。同时，确保你的应用有适当的权限来访问串口设备。在Android上，你可能需要在AndroidManifest.xml中声明权限，而在iOS上，你可能需要配置Info.plist。