在TCPClient（ReadLine（）中使用StreamReader.ReadLine（）从TCPServer Buffer读取消息（数据）直到断开连接才返回

Question

I have problem with StreamReader.ReadLine() method.I wrote a C# program, but only TCPclient side. I'm using Hercules program to create a TCPServer. I entered the port number and made a connection. Then I ran my program and clicked to Connect button. then, I had connection with TCPServer.

I have no problem with sending data from TCPClient to Hercules(TCPServer). As you see in the picture, I'm entering the string into "Entered to Send" EditText, then I clicked to Send button and I sent the String.(we can observe the sending data from the Received data part.)

Until here, I have no problem. After sending part, I cannot send data from hercules(TCPServer) to TCPClient. In order to send data, I wrote data into the Send part and clicked the Send button. after that, to see the coming data you should click the Show button .....the problem is right here. I can not read the data from the ReadStream Buffer . I debugged my program and I found the problematic part which is:

private void btnShow_Click(object sender, EventArgs e)
    {
        try
        {
            string gelen;
            gelen = read_stream.ReadLine();
            txtReceive.Text = gelen;
            MessageBox.Show(gelen, "you have message from server");
        }
        catch
        {
            MessageBox.Show("message could not taken !!!");
        }
    }

inside the try part the line;

gelen = read_stream.ReadLine();

has problem .ReadLine() is not reading the data from buffer. here is the interesting part, when you send data and click the Show button the program freezes, but if you close the connection from hercules.png by clicking Close button, read_stream.ReadLine(); is taking the data and putting into the Received: EditText.

• why it takes the data, after disconnection from TCPServer?
• May be the \\r\\n characters are the problem?
• I thought that it is waiting for next character. So, when I disconnected it works because it realizes three is no more character. My question is that:

How can I use read_stream.ReadLine(); to take sending data without disconnection?

    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Drawing;
    using System.Linq;
    using System.Text;
    using System.Windows.Forms;

    using System.Net;
    using System.Net.Sockets;

    using System.Threading;
    using System.Net.Sockets;
    using System.IO;
    using System.Drawing;
    using System.Collections;
    using System.ComponentModel;
    using System.Windows.Forms;
    using System.Data;

    namespace CSharpVeriDenemesi
    {
    public partial class Form1 : Form
    {
        //Burda server da tanımladıklarımızdan farklı olarak TcpClient sınıfı ile serverdan gelen bilgileri alıyoruz
    public TcpClient Client;
    private NetworkStream network_stream;
    private StreamReader read_stream;
    private StreamWriter write_stream;

    private string local_host = "localhost";
    private int port_number = 8001;
    public TcpListener listener;
    // IPAddress localAddress = IPAddress.Parse("127.0.0.1");

    public Form1()//form oluşunca otomatik oluşturulan fonksiyon
    {
        InitializeComponent();
    }

    private void btnConnect_Click(object sender, EventArgs e)//CONNECT
    {
        try
        {
            Client = new TcpClient(local_host, port_number);//İlk parametre bilgisayar adı ikincisi ise port numarasıdır.
            MessageBox.Show("Baglandi");
        }
        catch
        {
            MessageBox.Show("Baglanamadi");
            return;
        }
        network_stream = Client.GetStream();
        read_stream = new StreamReader(network_stream);
        write_stream = new StreamWriter(network_stream);

    }

    private void btnDisconnect_Click(object sender, EventArgs e)//DISCONNECT
    {
        txtSend.Text = "Disconnect clicked";
        try
        {
            write_stream.Close();
            read_stream.Close();
            network_stream.Close();
        }
        catch
        {
            MessageBox.Show("Düzgün kapatilamiyor !!!" );
        }
    }

    private void btnReset_Click(object sender, EventArgs e)//send ve receive text.box'larını resetliyor.
    {
        txtSend.Text = "";
        txtReceive.Text = "";     
        MessageBox.Show("Reset'e basıldı");          
    }

    private void Form1_Load(object sender, EventArgs e)//sayfa ilk açıldığında olcaklar için açılan dosya
    {

    }

    private void btnSend_Click(object sender, EventArgs e)//veriyi server'a gönderiyor
    {

        try
        {
            write_stream.WriteLine(txtSend.Text);
            write_stream.Flush();  //veriyi gönderiyor
            MessageBox.Show("Veri gönderildi");
        }
        catch {
            MessageBox.Show("Veri gönderilmedi !!!");          
        }            
    }

    private void btnShow_Click(object sender, EventArgs e)
    {
        try
        {
            string gelen;
            gelen = read_stream.ReadLine();
            txtReceive.Text = gelen;
            MessageBox.Show(gelen, "you have message from server");
        }
        catch
         {
            MessageBox.Show("message could not taken !!!");
        }
    }
    }
    }

here is my main.cs I forgot to add it. you can write it and try my project... note: here is the link for hercules it is portable, you can run it easily [ http://www.hw-group.com/products/hercules/index_en.html] 3

Answer 1

If your server side doesn't use Stream.WriteLine("something.."); then you will always have to wait for End of line char (\\r or \\n or \\r\\n) at client side when using ReadLine() function.

So the ReadLine() will complete only when connection is closed => your problem.

Your code:

        write_stream.WriteLine(txtSend.Text);
        write_stream.Flush();  //veriyi gönderiyor

is used at client side, to feedback server, it has no meaning with server sending data.

Try your client side by Reading char by char, or use Read() with BUFFER in specific length.