Question

I’m implementing really simple UDP server in C# language.

When I implemented the server on Console based application, it worked well.

But when I implemented it by using the same code on Windows based application,

it doesn’t works as before.

I guessed that it is the problem of thread thing.

So I putted thread on the code, but still doesn’t works.

The function of “ReceiveFrom()” doesn’t works as before.

  numReceived = udpSocket.ReceiveFrom(buffer, ref remoteEP);

what is a problem that I’m missing?

Thank you in advance.

  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.Runtime.InteropServices;
  using System.Net;
  using System.Net.Sockets;
  using System.Threading;

  namespace UDP_Server
  {
      public partial class Form1 : Form
      {

          private const int portNum = 5432;

          Socket udpSocket;

          byte[] buffer = new Byte[100];

          public Form1()
          {
              InitializeComponent();
          }

          private void button1_Click(object sender, EventArgs e)
          {
              ThreadStart threadStart = new ThreadStart(onServer);
              Thread thread = new Thread(threadStart);
              thread.Start();
          }

          private void onServer()
          {
              EndPoint localEP = new IPEndPoint(IPAddress.Parse("xxx.xxx.xxx.xxx"), portNum);
              //EndPoint remoteEP = new IPEndPoint(IPAddress.Any, 0);

              udpSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

              udpSocket.Bind(localEP);

              ThreadStart threadStart1 = new ThreadStart(OnReceive);
              Thread thread1 = new Thread(threadStart1);
              thread1.Start();
              //udpSocket.BeginReceiveFrom(buffer, 0, buffer.Length,
              //SocketFlags.None, ref remoteEP, new AsyncCallback(OnReceive), (object)this);
          }

          private void OnReceive()//IAsyncResult ar)
          {

              int numReceived = 0;
              EndPoint remoteEP = new IPEndPoint(IPAddress.Any, 0);

              Console.WriteLine("UDP Starting Server");
              Console.WriteLine("-----------------------------");

              while (true)
              {
                  numReceived = udpSocket.ReceiveFrom(buffer, ref remoteEP);

                  string s = Encoding.UTF8.GetString(buffer, 0, numReceived);

                  Console.WriteLine("Echo : {0}", s);
              }
          }
      }
  }

Answer 1

Looks as if your expecting it to print some output (which it is via the console window).You need to add all of the output you want to display in a windows forms control such as a rich text box and do:

RichTextbox1.Text += yourInput;