C# - APP - How To Make Server Detect That Client is Disconnected

[Ontrace]

hello,

I have Problem with Client Server Application

when I unplug the client network cable, the server still read the network stream
what function should I use to make server detect that the client is disconnect

here the code...

serverSide

public static void Main()
    {
        int recv;
        byte[] data = new byte[1024];
        TcpListener newsock = new TcpListener(9050);
        newsock.Start();
        Console.WriteLine("Waiting for a client...");
        TcpClient client = newsock.AcceptTcpClient();
        NetworkStream ns = client.GetStream();
        string welcome = "Welcome to my test server";
        data = Encoding.ASCII.GetBytes(welcome);
        ns.Write(data, 0, data.Length);
        while(true)
        {
            data = new byte[1024];
            recv = ns.Read(data, 0, data.Length);
            if (recv == 0)
                break;
 
            Console.WriteLine(
                Encoding.ASCII.GetString(data, 0, recv));
            ns.Write(data, 0, recv);
        }
        ns.Close();
        client.Close();
        newsock.Stop();
    }

Client Side

public static void Main()
    {
        byte[] data = new byte[1024];
        string input, stringData;
        TcpClient server;
        try
        {
            server = new TcpClient("10.8.101.75", 9050);
        } 
        catch (SocketException)
        {
            Console.WriteLine("Unable to connect to server");
            return;
        }
        NetworkStream ns = server.GetStream();
        int recv = ns.Read(data, 0, data.Length);
        stringData = Encoding.ASCII.GetString(data, 0, recv);
        Console.WriteLine(stringData);
        while(true)
        {
            input = Console.ReadLine();
            if (input == "exit")
                break;
            ns.Write(Encoding.ASCII.GetBytes(input), 0, input.Length);
            ns.Flush();
            data = new byte[1024];
            recv = ns.Read(data, 0, data.Length);
            stringData = Encoding.ASCII.GetString(data, 0, recv);
            Console.WriteLine(stringData);
        }
        Console.WriteLine("Disconnecting from server...");
        ns.Close();
        server.Close();