c# - 用于字符写入和读取的 UWP 串口通信(UWP 和 Arduino)

Question

我正在使用此代码但无法正常工作并抛出此异常:未将对象引用设置为对象的实例devices[0] 给我空值。

   private async void ConnectToSerialPort()
    {
        string selector = SerialDevice.GetDeviceSelector("COM7");
        DeviceInformationCollection devices = await DeviceInformation.FindAllAsync(selector);
        if (devices.Count > 0)
        {
            DeviceInformation deviceInfo = devices[0];
            SerialDevice serialDevice = await SerialDevice.FromIdAsync(deviceInfo.Id);
            Debug.WriteLine(serialDevice);
            serialDevice.BaudRate = 9600;
            serialDevice.DataBits = 8;
            serialDevice.StopBits = SerialStopBitCount.Two;
            serialDevice.Parity = SerialParity.None;

            DataWriter dataWriter = new DataWriter(serialDevice.OutputStream);
            dataWriter.WriteString("your message here");
            await dataWriter.StoreAsync();
            dataWriter.DetachStream();
            dataWriter = null;
        }
        else
        {
            MessageDialog popup = new MessageDialog("Sorry, no device found.");
            await popup.ShowAsync();
        }
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        ConnectToSerialPort();
    }

请帮我排除这个错误，我会非常感谢你。请帮助:(

Answer 1

您需要像这样在 Package.appxmanifest 中添加串行设备功能:

<Capabilities>
    <DeviceCapability Name="serialcommunication">
      <Device Id="any">
        <Function Type="name:serialPort" />
      </Device>
    </DeviceCapability>
  </Capabilities>

更多信息您可以引用Serial device capability usage .