Problems with closing TcpClient and NetworkStream

currently I am working on a simple client server chat program (wanted to get into client server communication things in C#). It works so far except for disconnecting properly from the server.

On the client I use this code here to close the connection:

client.Client.Disconnect(false); // client is the TcpClient
client.Close();

On the server there is a threaded loop waiting for messages from the client:

private void StartChat()
{
    int requestCount = 0;
    byte[] bytesFrom = new byte[10025];
    string dataFromClient = null;
    string rCount = null;

    while (true)
    {
        try
        {
            requestCount++;

            NetworkStream stream = tcpClient.GetStream();

            int bufferSize = (int)tcpClient.ReceiveBufferSize;
            if (bufferSize > bytesFrom.Length)
            {
                bufferSize = bytesFrom.Length;
            }

            stream.Read(bytesFrom, 0, bufferSize);
            dataFromClient = System.Text.Encoding.UTF8.GetString(bytesFrom);
            dataFromClient = dataFromClient.Substring(0, dataFromClient.IndexOf("$"));
            rCount = Convert.ToString(requestCount);

            string message = client.Name + " says: " + dataFromClient;
            program.Broadcast(message);

        }
        catch(Exception ex) when (ex is ObjectDisposedException || ex is InvalidOperationException || ex is System.IO.IOException)
        { 
            program.UserDisconnected(client);
            break;
        }
        catch(ArgumentOutOfRangeException ex)
        {
            Debug.WriteLine(ex.ToString());
            break;
        }
        catch(Exception ex)
        {
            Debug.WriteLine(ex.ToString());
            break;
        }
    }

If the client disconnects with the code shown above the function is fetching the stream all the time and producing such an output:

\0\0\0\0\0\0\0 [and so on]

In this case the ArgumentOutOfRangeException will be thrown because there is no index of $. I added a break to avoid and endless execution of the loop.

Surprisingly the ObjectDisposedException will not be thrown. Also the System.IO.IOException will not be thrown however it should because the stream was closed so the connection has been refused.

If I just close the client application which is connected to the server the server doesn't stops the loop, it just waits for a stream which will never come because the client disconnected.

So how could I detect if the client is disconnected or not reachable any more? And is the way I am closing the client connection a proper way to close a connection?

Thanks for your help!

Update:

private void StartChat()
{
    int requestCount = 0;
    byte[] bytesFrom = new byte[10025];
    string dataFromClient = null;
    string rCount = null;

    while (true)
    {
        try
        {
            requestCount++;

            NetworkStream stream = tcpClient.GetStream();
            stream.ReadTimeout = 4000;

            int bufferSize = (int)tcpClient.ReceiveBufferSize;
            if (bufferSize > bytesFrom.Length)
            {
                bufferSize = bytesFrom.Length;
            }


            // Wait for a client message. If no message is recieved within the ReadTimeout a IOException will be thrown
            try
            {
                int bytesRead = stream.Read(bytesFrom, 0, bufferSize);
                stream.Flush();

                if (bytesRead == 0)
                {
                    throw new System.IO.IOException("Connection seems to be refused or closed.");
                }
            }
            catch (System.IO.IOException)
            {
                byte[] ping = System.Text.Encoding.UTF8.GetBytes("%");
                stream.WriteTimeout = 1;

                stream.Write(ping, 0, ping.Length);
                continue;
            }


            dataFromClient = System.Text.Encoding.ASCII.GetString(bytesFrom);
            dataFromClient = dataFromClient.Substring(0, dataFromClient.IndexOf("$"));
            rCount = Convert.ToString(requestCount);

            string message = client.Name + " says: " + dataFromClient;
            program.Broadcast(message);

        }
        catch(Exception ex) when (ex is ObjectDisposedException || ex is InvalidOperationException || ex is System.IO.IOException)
        {
            Debug.WriteLine(ex.ToString());
            program.UserDisconnected(client);
            break;
        }
        catch(ArgumentOutOfRangeException ex)
        {
            Debug.WriteLine(ex.ToString());
        }
        catch(Exception ex)
        {
            Debug.WriteLine(ex.ToString());
            break;
        }
    }
}