receive.cs

...        
private Thread receive_thread = null;
private void button1_Click(object sender, EventArgs e)
{
    if (null != receive_thread)
    {
        receive_thread.Abort();
    }
    receive_thread = new Thread(receive_data);
    receive_thread.Start();            
}

private UdpClient receiving_UdpClient = new UdpClient(49001);
private void receive_data() 
{
    while (true)
    {
        IPEndPoint RemoteIpEndPoint = new IPEndPoint(IPAddress.Any, 0);

        Byte[] receiveBytes = receiving_UdpClient.Receive(ref RemoteIpEndPoint);

        string[] data = Encoding.ASCII.GetString(receiveBytes).Split(',');

        float aileron = float.Parse(data[0]);
        aileron_recv_textBox.Text = aileron.ToString();
                
        float elevator = float.Parse(data[1]);
        elevator_recv_textBox.Text = elevator.ToString();
                
        float throttle = float.Parse(data[2]);
        throttle_recv_textBox.Text = throttle.ToString();

        float airpeed = float.Parse(data[3]);
        airspeed_recv_textBox.Text = airpeed.ToString();

        Thread.Sleep(80);
    }
}
...