Very simple UDP chat application not working !!!

[karmafree]

Hi,

I have a very, very simple UDP chat applicaton written in C# .NET that sends and receives messages to myself or to any other computer. However, it doesn't seem to be working properly; - I can send messages (I think) but can't receive them. This may be a long shot, but if you could, do you reckon you can take a quick look at it?! I would be very grateful!

Thank you,
Steve.



using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace Chat
{
/// <summary>
/// Summary description for Form1.
/// </summary>
public class Chat : System.Windows.Forms.Form
{
private System.Windows.Forms.TextBox textBoxMyIPAddress;
private System.Windows.Forms.TextBox textBoxMyPort;
private System.Windows.Forms.TextBox textBoxRemoteIPAddress;
private System.Windows.Forms.TextBox textBoxRemotePort;
private System.Windows.Forms.Label labelMyIPAddress;
private System.Windows.Forms.Label labelMyPort;
private System.Windows.Forms.Label labelRemoteIPAddress;
private System.Windows.Forms.Label labelRemotePort;
private System.Windows.Forms.Label labelUsername;
private System.Windows.Forms.TextBox textBoxUsername;
private System.Windows.Forms.RichTextBox richTextBoxConversation;
private System.Windows.Forms.RichTextBox richTextBoxMessage;
private System.Windows.Forms.Button buttonSend;
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.Container components = null;

private System.Net.Sockets.UdpClient udpClient;

private System.Text.UnicodeEncoding unicodeEncoding;

private System.Threading.ThreadStart threadStart;
private System.Threading.Thread thread;

private bool isChatting;

public Chat()
{
//
// Required for Windows Form Designer support
//
InitializeComponent();

//
// TODO: Add any constructor code after InitializeComponent call
//

this.udpClient = new System.Net.Sockets.UdpClient();

this.unicodeEncoding = new System.Text.UnicodeEncoding();

this.threadStart = new System.Threading.ThreadStart(Listen);
this.thread = new System.Threading.Thread(this.threadStart);
this.thread.Start();

this.isChatting = false;
}

/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}


#region Windows Form Designer generated code


/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new Chat());
}

protected void Listen()
{
try
{
while (this.isChatting)
{
System.Net.IPEndPoint ipEndPoint;

if ((this.textBoxMyIPAddress.Text.Trim().Equals(string.Empty)) || ((this.textBoxMyPort.Text.Trim().Equals(string.Empty))))
{
ipEndPoint = null;
}
else
{
ipEndPoint = new System.Net.IPEndPoint(System.Net.IPAddress.Parse(this.textBoxMyIPAddress.Text.Trim()), System.Convert.ToInt32(this.textBoxMyPort.Text.Trim()));
}

byte[] data = this.udpClient.Receive(ref ipEndPoint);

this.richTextBoxConversation.Text += this.unicodeEncoding.GetString(data) + &quot;\r\n&quot;;
}
}
catch (System.Exception exception)
{
System.Windows.Forms.MessageBox.Show(&quot;Listen()&quot; + &quot;\n&quot; + exception.Message);
}
}

private void buttonSend_Click(object sender, System.EventArgs e)
{
try
{
System.Net.IPEndPoint ipEndPoint = new System.Net.IPEndPoint(System.Net.IPAddress.Parse(this.textBoxRemoteIPAddress.Text.Trim()), System.Convert.ToInt32(this.textBoxRemotePort.Text.Trim()));

byte[] data = this.unicodeEncoding.GetBytes(this.textBoxUsername.Text + &quot;:&quot; + &quot; &quot; + this.richTextBoxMessage.Text);

this.udpClient.Send(data, data.Length, ipEndPoint);

this.isChatting = true;

this.richTextBoxMessage.Clear();
this.richTextBoxMessage.Focus();
}
catch (System.Exception exception)
{
System.Windows.Forms.MessageBox.Show(&quot;Incorrect Remote IP Address or Remote Port Number.&quot; + &quot;\n\n&quot; + &quot;buttonSend_Click()&quot; + &quot;\n&quot; + exception.Message);
}
}

private void Chat_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
if (this.isChatting)
{
this.isChatting = false;

this.udpClient.Close();
}
}
}
}