How do we read the code that we put from arduino

See more:

C#

Arduino

Bluetooth

What we want to do is when the arduino will send a signal to the C# app that we are making and when the arduino sent the A signal, a notification popup should appear, if it did not send, the notification box will not appear.

What I have tried:

{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            serialPort1.Open();
        }

        private void serialPort1_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
        {

            if (serialPort1.Read("A")) ;
            { Notification.Enabled = true; }
            else
            { Notification.Enabled = false; }
        }

        private void Notification_Click(object sender, EventArgs e)
        {
            PopupNotifier popup = new PopupNotifier();
            popup.Image = Properties.Resources.info;
            popup.TitleText = "Alert";
            popup.ContentText = "Hey";
            popup.Popup();
        }
    }
}