如何让Android上的客户端在C#上监听服务器

我在Android上有一个客户端，在c#上有一台服务器。客户端向服务器发送消息，一切正常。但我需要服务器按请求发送指定目录中的文件夹和文件列表，但我不知道如何做到这一点，因为客户端不会从服务器收到任何消息。客户端用于侦听的代码部分不起作用，应用程序只是卡住，直到我关闭服务器应用程序，然后它又起作用，但仍然没有读取任何内容。提前感谢

客户：

package com.app.client.app;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import java.io.BufferedReader;
import java.io.BufferedWriter; 
import java.io.IOException; 
import java.io.InputStream;
import java.io.OutputStreamWriter; 
import java.io.InputStreamReader;
import java.io.PrintWriter; 
import java.net.InetAddress; 
import java.net.Socket; 
import java.net.UnknownHostException; 
import android.util.Log; 
public class my_activity extends Activity { 
private TextView txt;
@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 
    Button b = (Button)findViewById(R.id.button1);
    txt = (TextView)findViewById(R.id.textView1);

    b.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
        connectSocket("Hello");
        }
    });
} 
private void connectSocket(String a){ 
    try { 
        InetAddress serverAddr = InetAddress.getByName("192.168.1.2"); 
        Log.d("TCP", "C: Connecting..."); 
        Socket socket = new Socket(serverAddr, 4444); 
        message = "1";
        PrintWriter out = null;
        BufferedReader in = null;
        try { 
            Log.d("TCP", "C: Sending: '" + message + "'"); 
            out = new PrintWriter( new BufferedWriter( new OutputStreamWriter(socket.getOutputStream())),true); 
            in = new BufferedReader(new InputStreamReader(socket.getInputStream()));                
            out.println(message);
            while ((in.readLine()) != null) {
                txt.append(in.readLine());
            }
            Log.d("TCP", "C: Sent."); 
            Log.d("TCP", "C: Done.");               
        } catch(Exception e) { 
            Log.e("TCP", "S: Error", e); 
        } finally { 
            socket.close(); 
        } 
    } catch (UnknownHostException e) { 
        // TODO Auto-generated catch block 
        Log.e("TCP", "C: UnknownHostException", e); 
        e.printStackTrace(); 
    } catch (IOException e) { 
        // TODO Auto-generated catch block 
        Log.e("TCP", "C: IOException", e); 
        e.printStackTrace(); 
    }       
} 
} 

服务器：

using System;
using System.Text;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Windows.Forms;
public class serv {
    public static void Main() {
    try {
    IPAddress ipAd = IPAddress.Parse("192.168.1.2");
     // use local m/c IP address, and 
     // use the same in the client

/* Initializes the Listener */
    TcpListener myList=new TcpListener(ipAd,4444);
/* Start Listeneting at the specified port */        
    myList.Start();
    Console.WriteLine("The server is running at port 4444...");    
    Console.WriteLine("The local End point is  :" + 
                      myList.LocalEndpoint );
    Console.WriteLine("Waiting for a connection.....");
    m:
    Socket s=myList.AcceptSocket();
    Console.WriteLine("Connection accepted from " + s.RemoteEndPoint);
    byte[] b=new byte[100];
    int k=s.Receive(b);
    char cc = ' ';
    string test = null;
    Console.WriteLine("Recieved...");
    for (int i = 0; i < k-1; i++)
    {
        Console.Write(Convert.ToChar(b[i]));
        cc = Convert.ToChar(b[i]);
        test += cc.ToString();
    }
    switch (test)
    {
        case "1":                 
            break;

    }
    ASCIIEncoding asen=new ASCIIEncoding();
    s.Send(asen.GetBytes("The string was recieved by the server."));
    Console.WriteLine("'nSent Acknowledgement");

/* clean up */
    goto m;    
    s.Close();
    myList.Stop();
    Console.ReadLine();
}
catch (Exception e) {
    Console.WriteLine("Error..... " + e.StackTrace);
}    
}
}