System.IO.IOException: Too many posts were made to a semaphore

Question

I'm developing an App in .net (Xamarin) and I'm trying to establish a connection with a serial port. Whenever I try to open the connection with the port I'm getting this error_message:

System.IO.IOException: 'Too many posts were made to a semaphore'

Can't find anything specific by googling. Any help appreciated!

Example code:

private void Open()   
    {
        IsOpen = true;
        _serialPort.PortName = "COM3";
        _serialPort.BaudRate = 19200;
        _serialPort.Parity = Parity.None;
        _serialPort.DataBits = 8;
        _serialPort.StopBits = StopBits.One;
        _serialPort.Handshake = Handshake.None;
        _serialPort?.Open();
    }

Try changing `_serialPort?.Open();` to `_serialPort.Open();` — Tu deschizi eu inchid, Aug 27 '21 at 15:49

ryan151 · Answer 1 · 2021-09-01T16:57:46.413

2

This is because you need to add

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

to your Package.appxmanifest.

Took me awhile to figure this out myself.

edited Sep 01 '21 at 16:57

answered Sep 01 '21 at 16:14

ryan151

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System.IO.IOException: Too many posts were made to a semaphore

1 Answers1