.NET MAUI跨平臺串口通訊方案

文章目錄

- - MAUI項目架構設計
  - 平臺特定實現
  - - 接口定義
    - Windows平臺實現
    - Android平臺實現
  - MAUI主界面實現
  - 依賴注入配置
  - 相關學習資源
  - - .NET MAUI開發
    - 移動端開發
    - 平臺特定實現
    - 依賴注入與架構
    - 移動應用發布
    - 跨平臺開發最佳實踐
    - 性能優化
    - 測試與調試
    - 開源項目參考

MAUI項目架構設計

平臺特定實現

接口定義

/// <summary>
/// 跨平臺串口服務接口
/// </summary>
public interface ISerialPortService
{/// <summary>/// 獲取可用串口列表/// </summary>Task<string[]> GetAvailablePortsAsync();/// <summary>/// 連接到指定串口/// </summary>Task<bool> ConnectAsync(string portName, int baudRate);/// <summary>/// 斷開串口連接/// </summary>Task DisconnectAsync();/// <summary>/// 發送數據/// </summary>Task SendDataAsync(byte[] data);/// <summary>/// 發送文本數據/// </summary>Task SendTextAsync(string text);/// <summary>/// 數據接收事件/// </summary>event EventHandler<SerialDataEventArgs> DataReceived;/// <summary>/// 連接狀態變化事件/// </summary>event EventHandler<bool> ConnectionChanged;/// <summary>/// 是否已連接/// </summary>bool IsConnected { get; }
}/// <summary>
/// 串口數據事件參數
/// </summary>
public class SerialDataEventArgs : EventArgs
{public byte[] Data { get; set; }public string Text { get; set; }public DateTime Timestamp { get; set; }
}

Windows平臺實現

#if WINDOWS
using System.IO.Ports;/// <summary>
/// Windows平臺串口服務實現
/// </summary>
public class WindowsSerialPortService : ISerialPortService
{private SerialPort _serialPort;private bool _isConnected;public bool IsConnected => _isConnected;public event EventHandler<SerialDataEventArgs> DataReceived;public event EventHandler<bool> ConnectionChanged;public WindowsSerialPortService(){_serialPort = new SerialPort();_serialPort.DataReceived += OnDataReceived;}public async Task<string[]> GetAvailablePortsAsync(){return await Task.FromResult(SerialPort.GetPortNames());}public async Task<bool> ConnectAsync(string portName, int baudRate){try{if (_isConnected)await DisconnectAsync();_serialPort.PortName = portName;_serialPort.BaudRate = baudRate;_serialPort.DataBits = 8;_serialPort.Parity = Parity.None;_serialPort.StopBits = StopBits.One;_serialPort.Open();_isConnected = true;ConnectionChanged?.Invoke(this, true);return true;}catch (Exception ex){_isConnected = false;ConnectionChanged?.Invoke(this, false);return false;}}public async Task DisconnectAsync(){try{if (_serialPort?.IsOpen == true){_serialPort.Close();}_isConnected = false;ConnectionChanged?.Invoke(this, false);}catch (Exception){// 忽略關閉時的異常}}public async Task SendDataAsync(byte[] data){if (!_isConnected || !_serialPort.IsOpen)throw new InvalidOperationException("串口未連接");await Task.Run(() => _serialPort.Write(data, 0, data.Length));}public async Task SendTextAsync(string text){var data = System.Text.Encoding.UTF8.GetBytes(text);await SendDataAsync(data);}private void OnDataReceived(object sender, SerialDataReceivedEventArgs e){try{var buffer = new byte[_serialPort.BytesToRead];var bytesRead = _serialPort.Read(buffer, 0, buffer.Length);var eventArgs = new SerialDataEventArgs{Data = buffer.Take(bytesRead).ToArray(),Text = System.Text.Encoding.UTF8.GetString(buffer, 0, bytesRead),Timestamp = DateTime.Now};DataReceived?.Invoke(this, eventArgs);}catch (Exception){// 處理讀取異常}}
}
#endif

Android平臺實現

#if ANDROID
using Android.Hardware.Usb;
using AndroidX.Core.Content;/// <summary>
/// Android平臺串口服務實現
/// 基于USB Host模式
/// </summary>
public class AndroidSerialPortService : ISerialPortService
{private UsbManager _usbManager;private UsbDevice _usbDevice;private UsbDeviceConnection _connection;private UsbInterface _interface;private UsbEndpoint _endpointIn;private UsbEndpoint _endpointOut;private bool _isConnected;private CancellationTokenSource _readCancellation;public bool IsConnected => _isConnected;public event EventHandler<SerialDataEventArgs> DataReceived;public event EventHandler<bool> ConnectionChanged;public AndroidSerialPortService(){var context = Platform.CurrentActivity ?? Android.App.Application.Context;_usbManager = (UsbManager)context.GetSystemService(Android.Content.Context.UsbService);}public async Task<string[]> GetAvailablePortsAsync(){var deviceList = _usbManager.DeviceList;var portNames = new List<string>();foreach (var device in deviceList.Values){// 檢查是否為串口設備（根據VID/PID或設備類型判斷）if (IsSerialDevice(device)){portNames.Add($"USB-{device.DeviceName}");}}return portNames.ToArray();}public async Task<bool> ConnectAsync(string portName, int baudRate){try{// Android USB串口連接實現// 這里需要根據具體的USB轉串口芯片實現var deviceList = _usbManager.DeviceList;foreach (var device in deviceList.Values){if ($"USB-{device.DeviceName}" == portName){_usbDevice = device;break;}}if (_usbDevice == null)return false;// 請求USB權限if (!_usbManager.HasPermission(_usbDevice)){// 需要請求權限return false;}_connection = _usbManager.OpenDevice(_usbDevice);if (_connection == null)return false;// 配置USB設備_interface = _usbDevice.GetInterface(0);_connection.ClaimInterface(_interface, true);// 找到輸入輸出端點for (int i = 0; i < _interface.EndpointCount; i++){var endpoint = _interface.GetEndpoint(i);if (endpoint.Direction == UsbAddressing.In)_endpointIn = endpoint;else if (endpoint.Direction == UsbAddressing.Out)_endpointOut = endpoint;}_isConnected = true;ConnectionChanged?.Invoke(this, true);// 啟動數據讀取StartDataReading();return true;}catch (Exception){_isConnected = false;ConnectionChanged?.Invoke(this, false);return false;}}public async Task DisconnectAsync(){_isConnected = false;_readCancellation?.Cancel();_connection?.ReleaseInterface(_interface);_connection?.Close();ConnectionChanged?.Invoke(this, false);}public async Task SendDataAsync(byte[] data){if (!_isConnected || _connection == null || _endpointOut == null)throw new InvalidOperationException("設備未連接");await Task.Run(() =>{_connection.BulkTransfer(_endpointOut, data, data.Length, 1000);});}public async Task SendTextAsync(string text){var data = System.Text.Encoding.UTF8.GetBytes(text);await SendDataAsync(data);}private void StartDataReading(){_readCancellation = new CancellationTokenSource();Task.Run(async () =>{var buffer = new byte[1024];while (!_readCancellation.Token.IsCancellationRequested && _isConnected){try{var bytesRead = _connection.BulkTransfer(_endpointIn, buffer, buffer.Length, 100);if (bytesRead > 0){var eventArgs = new SerialDataEventArgs{Data = buffer.Take(bytesRead).ToArray(),Text = System.Text.Encoding.UTF8.GetString(buffer, 0, bytesRead),Timestamp = DateTime.Now};DataReceived?.Invoke(this, eventArgs);}await Task.Delay(10);}catch (Exception){// 處理讀取異常}}});}private bool IsSerialDevice(UsbDevice device){// 根據VID/PID或設備類型判斷是否為串口設備// 這里可以添加常見USB轉串口芯片的識別邏輯return device.DeviceClass == UsbClass.CdcData || device.DeviceClass == UsbClass.Comm;}
}
#endif

MAUI主界面實現

/// <summary>
/// MAUI主頁面
/// </summary>
public partial class MainPage : ContentPage
{private readonly ISerialPortService _serialService;private readonly ObservableCollection<string> _receivedMessages;public MainPage(ISerialPortService serialService){InitializeComponent();_serialService = serialService;_receivedMessages = new ObservableCollection<string>();MessagesCollectionView.ItemsSource = _receivedMessages;// 綁定事件_serialService.DataReceived += OnDataReceived;_serialService.ConnectionChanged += OnConnectionChanged;// 加載可用串口LoadAvailablePorts();}private async void LoadAvailablePorts(){try{var ports = await _serialService.GetAvailablePortsAsync();PortPicker.ItemsSource = ports;if (ports.Length > 0)PortPicker.SelectedIndex = 0;}catch (Exception ex){await DisplayAlert("錯誤", $"加載串口列表失敗: {ex.Message}", "確定");}}private async void OnConnectClicked(object sender, EventArgs e){try{if (_serialService.IsConnected){await _serialService.DisconnectAsync();}else{if (PortPicker.SelectedItem == null){await DisplayAlert("提示", "請選擇串口", "確定");return;}var portName = PortPicker.SelectedItem.ToString();var baudRate = int.Parse(BaudRatePicker.SelectedItem?.ToString() ?? "9600");var success = await _serialService.ConnectAsync(portName, baudRate);if (!success){await DisplayAlert("錯誤", "連接失敗", "確定");}}}catch (Exception ex){await DisplayAlert("錯誤", $"連接操作失敗: {ex.Message}", "確定");}}private async void OnSendClicked(object sender, EventArgs e){try{if (!_serialService.IsConnected){await DisplayAlert("提示", "請先連接串口", "確定");return;}var text = SendEntry.Text;if (string.IsNullOrWhiteSpace(text)){await DisplayAlert("提示", "請輸入要發送的內容", "確定");return;}await _serialService.SendTextAsync(text + "\r\n");SendEntry.Text = string.Empty;// 在消息列表中顯示發送的內容_receivedMessages.Add($"[發送] {DateTime.Now:HH:mm:ss} - {text}");}catch (Exception ex){await DisplayAlert("錯誤", $"發送失敗: {ex.Message}", "確定");}}private void OnDataReceived(object sender, SerialDataEventArgs e){// 在UI線程中更新界面MainThread.BeginInvokeOnMainThread(() =>{_receivedMessages.Add($"[接收] {e.Timestamp:HH:mm:ss} - {e.Text.Trim()}");// 自動滾動到最新消息if (_receivedMessages.Count > 0){MessagesCollectionView.ScrollTo(_receivedMessages.Last());}});}private void OnConnectionChanged(object sender, bool isConnected){MainThread.BeginInvokeOnMainThread(() =>{ConnectButton.Text = isConnected ? "斷開" : "連接";StatusLabel.Text = isConnected ? "已連接" : "未連接";StatusLabel.TextColor = isConnected ? Colors.Green : Colors.Red;// 控制界面元素的啟用狀態PortPicker.IsEnabled = !isConnected;BaudRatePicker.IsEnabled = !isConnected;SendButton.IsEnabled = isConnected;SendEntry.IsEnabled = isConnected;});}private async void OnRefreshPortsClicked(object sender, EventArgs e){await LoadAvailablePorts();}
}

依賴注入配置

/// <summary>
/// MAUI應用程序配置
/// </summary>
public static class MauiProgram
{public static MauiApp CreateMauiApp(){var builder = MauiApp.CreateBuilder();builder.UseMauiApp<App>().ConfigureFonts(fonts =>{fonts.AddFont("OpenSans-Regular.ttf", "OpenSansRegular");});// 注冊平臺特定的串口服務
#if WINDOWSbuilder.Services.AddSingleton<ISerialPortService, WindowsSerialPortService>();
#elif ANDROIDbuilder.Services.AddSingleton<ISerialPortService, AndroidSerialPortService>();
#elif IOSbuilder.Services.AddSingleton<ISerialPortService, iOSSerialPortService>();
#elif MACCATALYSTbuilder.Services.AddSingleton<ISerialPortService, MacCatalystSerialPortService>();
#endif// 注冊頁面builder.Services.AddTransient<MainPage>();return builder.Build();}
}