UWP -无法读取串行端口COM

Question

我需要读取电子天平的重量，我可以发送命令返回我的重量，但天平没有反应。我认为这是一种老式的HB交易。

这是为Windows10开发的，以前有一个用Visual Fox Pro编写的代码，但非常旧，客户想要升级。

显然，我可以连接到天平并发送命令来返回我的体重，但天平永远不会响应。

private async void Button_Click(object sender, RoutedEventArgs e)
    {
        try
        {
            var deviceSelector = SerialDevice.GetDeviceSelector("COM5");
            var devices = await DeviceInformation.FindAllAsync(deviceSelector);
            if (devices.Any())
            {
                var deviceId = devices.First().Id;
                serialPort = await SerialDevice.FromIdAsync(deviceId);

                if (serialPort != null)
                {
                    serialPort.BaudRate = 9600;
                    serialPort.StopBits = SerialStopBitCount.One;
                    serialPort.DataBits = 8;
                    serialPort.Parity = SerialParity.None;
                    serialPort.Handshake = SerialHandshake.None;

                    dataWriteObject = new DataWriter(serialPort.OutputStream);
                    await WriteAsync(WriteCancellationTokenSource.Token);

                    dataReaderObject = new DataReader(serialPort.InputStream);
                    await ReadAsync(ReadCancellationTokenSource.Token);

                }
            }


        }
        catch (Exception ex)
        {
            TxtRespuesta.Text = ex.Message;
        }
        finally
        {
            serialPort.Dispose();
            serialPort = null;
        }
    }

    private async Task ReadAsync(CancellationToken cancellationToken)
    {

        Task<UInt32> loadAsyncTask;

        uint ReadBufferLength = 1024;

        // Don't start any IO if we canceled the task
        lock (ReadCancelLock)
        {
            cancellationToken.ThrowIfCancellationRequested();

            // Cancellation Token will be used so we can stop the task operation explicitly
            // The completion function should still be called so that we can properly handle a canceled task
            dataReaderObject.InputStreamOptions = InputStreamOptions.Partial;
            loadAsyncTask = dataReaderObject.LoadAsync(ReadBufferLength).AsTask(cancellationToken);
        }

        UInt32 bytesRead = await loadAsyncTask;
        if (bytesRead > 0)
        {
            TxtRespuesta.Text += dataReaderObject.ReadString(bytesRead);
        }
        //rootPage.NotifyUser("Read completed - " + bytesRead.ToString() + " bytes were read", NotifyType.StatusMessage);
    }

    private async Task WriteAsync(CancellationToken cancellationToken)
    {

        Task<UInt32> storeAsyncTask;
        String cadena = "@GI;23;";
        char[] buffer = cadena.ToArray();
        cadena.CopyTo(0, buffer, 0, cadena.Length);
        String InputString = new string(buffer);
        dataWriteObject.WriteString(InputString);

        // Don't start any IO if we canceled the task
        lock (WriteCancelLock)
        {
            cancellationToken.ThrowIfCancellationRequested();
            storeAsyncTask = dataWriteObject.StoreAsync().AsTask(cancellationToken);
        }

        UInt32 bytesWritten = await storeAsyncTask;
        if (bytesWritten > 0)
        {

        }
        //rootPage.NotifyUser("Write completed - " + bytesWritten.ToString() + " bytes written", NotifyType.StatusMessage);
    }

Answer 1

当然，首先，您的应用程序必须在应用程序清单中声明它正在进行串行通信：

<DeviceCapability Name="serialcommunication">
    <Device Id="vidpid:xxxx xxxx">
      <Function Type="name:serialPort"/>
    </Device>
</DeviceCapability>

这会是缺失的部分吗？