Question

我在Android上有一个客户端，在c＃上有服务器。客户端向服务器发送消息，没关系。但是我需要服务器在指定目录中发送文件夹和文件的请求列表，并且不知道如何做，因为客户端没有从服务器获取任何消息。客户端的部分代码旨在监听不起作用，应用程序只是停止，直到我关闭服务器应用程序，然后它再次工作，但仍然没有读取任何东西。提前致谢

客户端：

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);
}    
}

}

Answer 1

好的，我找到了解决问题的方法。

在您发送文字的c＃服务器中：

ASCIIEncoding asen = new ASCIIEncoding();
s.Send(asen.GetBytes("The string was recieved by the server."));
s.Close();

确保在发送数据后关闭套接字。这就是你的应用程序挂起的原因。 IT正在等待来自服务器的更多输入

此外，在您收到的Java中更改为

String text = "";
String finalText = "";
while ((text = in.readLine()) != null) {
    finalText += text;
    }
txt.setText(finalText);

注意你在该循环中如何做2个readInputs。 while语句执行一个..并且设置文本执行一个..所以你基本上试图在一个循环中读取2行。改变我上面发布的内容将解决这个问题

Answer 2

要避免NetworkOnMainThreadException，您需要在新线程中执行通信代码。

在Android客户端中：

 @Override
 public void onClick(View v) {

 new Thread(new Runnable() {
        public void run() {
            connectSocket("Hello");
                }
        }).start();

 }

Answer 3

感谢您的代码示例！

仅供参考：

您需要设置以下权限：

    <uses-permission android:name="android.permission.INTERNET" />

如何让Android上的客户端在C＃上监听服务器？

3 个答案: