Synchronous read write socket programming in C# while waiting for user input

Question

I have two C# programs interacting via TCP/IP synchronous communication. One of the essential libraries I'm using is System.Net.Sockets. The server is written in C# Windows form while the client is in console only. The latter is such because it will be interfaced with a microcontroller, so having it in Windows form is most likely not possible and unnecessary.

I have successfully sent data from the server to the client. Now, I'm working on sending data from the client to the server once you've pressed certain keys. I am using keys for simulation purposes since the device that will give the data are fingerprint scanner, barcode reader, and magnetic lock. Once you've pressed number 1, for example, the program will send a data. I've successfully sent data from the client to the server using hardcoding. My problem is on synchronous reading and writing at the client socket.

In both C# programs, read() is threaded. For the server, write() is activated once you've pressed a button; for the client, once you've pressed a key on the keyboard.

I've read different forums and applied methods such as using Console.KeyAvailable, delegate, threading, but I can't execute them properly. I have little successes with the latter two but for the Console.KeyAvailable, I can write and read to and from the socket but there are errors on synchronization.

Here's my send() and receive() codes for client.

//********************SEND DATA TO CLIENT********************
static void sendToClient()
{
    if (client.Connected)
    {
        sendBuffer = new Byte[1024];
        try
        {
            device = Console.Read();
            #region Data to send per device
            switch (device)
            {
                case 1: // barcode
                    {
                        dataToSend = "bar1234";
                    }
                    break;
                case 2: // fingerprint
                    {
                        dataToSend = "fingerprint5678";
                    }
                    break;
                case 3: // lock
                    {
                        dataToSend = "lock8910";
                    }
                    break;
                default:
                    break;
            }
            #endregion

            sendStream = client.GetStream();
            sendBuffer = Encoding.ASCII.GetBytes(dataToSend);
            sendStream.Write(sendBuffer, 0, sendBuffer.Length);
            Console.WriteLine("Data sent!");

            Console.Clear();
            sendStream.Flush();
        }
        // insert catch statements
    }
}

//********************RECEIVE DATA FROM CLIENT********************
static void receiveFromClient()
        {
            receiveStream = client.GetStream();
            try
            {
                sendToClient();
                strReceivedData = new StringBuilder();
                receiveBuffer = new Byte[1024];
                while(client.Connected)
                {
                    while (!(Console.KeyAvailable))
                    {
                        try
                        {
                            byteRead = receiveStream.Read(receiveBuffer, 0, receiveBuffer.Length);
                        }
                        // insert catch statements
                        strReceivedData.AppendFormat("{0}", Encoding.ASCII.GetString(receiveBuffer, 0, byteRead));
                        Console.WriteLine(strReceivedData.ToString());

                        strReceivedData.Clear();
                        receiveStream.Flush();
                    }
                    if (Console.KeyAvailable)
                        sendToClient();
                }
            }
             // insert catch statements
        }
    }
}

Question is, how do you synchronize these two things?

• Waiting for a user input then writing to a socket
• Listening/reading from a socket

Any help is appreciated. Thanks!