用于字符写入和读取的UWP串行端口通信（UWP和Arduino）

Question

我正在使用此代码但没有工作并抛出此异常：对​​象引用未设置为对象的实例 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();
    }

请帮我删除此错误，我将非常感谢你。 请帮忙:(

Answer 1

您需要在Package.appxmanifest中添加串行设备功能，如下所示：

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

有关详细信息，请参阅Serial device capability usage。