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Join Date: Apr 2004

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johnroach1985 johnroach1985 is offline

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Thread's colliding?

Nov 25th, 2007

Hi. I am trying to figure out this code I found on the net that allows users to chat with each other. It gives a thread error that I just can't fix. Please help me.

This is the Form1.cs file

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 C# Syntax (Toggle Plain Text) 
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Text;
using System.Security.Principal;
using System.Reflection;
 
namespace LanChat
{
	public class LanChat : System.Windows.Forms.Form
	{
		Thread thread;
		bool IsThreadRunning = false;
		ReaderWriterLock rwl = new ReaderWriterLock();
		ArrayList userList = new ArrayList();
 
		public System.Windows.Forms.RichTextBox richTextBoxRecieveMsg;
        public System.Windows.Forms.Label label1;
        public System.Windows.Forms.ComboBox comboBoxUserNames;
        public System.Windows.Forms.RichTextBox richTextBoxSendMsg;
        public System.Windows.Forms.Button buttonStop;
        public System.Windows.Forms.Button buttonAdvertise;
        public System.Windows.Forms.Button buttonSend;
        public System.Windows.Forms.ContextMenu contextMenuNotify;
        public System.Windows.Forms.MenuItem menuItem3;
        public System.Windows.Forms.MenuItem menuItemExit;
        public System.Windows.Forms.MenuItem menuItemOpen;
        public System.Windows.Forms.MenuItem menuItemAbout;
        public System.Windows.Forms.NotifyIcon notifyIcon;
        public PictureBox pictureBox1;
        public System.ComponentModel.IContainer components;
 
		public LanChat()
		{
			InitializeComponent();
			thread = new Thread(new ThreadStart(MulticastListener));
			thread.Start();
			String message = "Hello$"  + GetUserName();
			MulticastSend("224.168.100.2", 1000, message);
			notifyIcon.Icon = LoadIcon();
			this.Icon = LoadIcon();
		}
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if (components != null) 
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}
		#region Windows Form Designer generated code
		private void InitializeComponent()
		{
            this.components = new System.ComponentModel.Container();
            this.richTextBoxRecieveMsg = new System.Windows.Forms.RichTextBox();
            this.label1 = new System.Windows.Forms.Label();
            this.comboBoxUserNames = new System.Windows.Forms.ComboBox();
            this.buttonSend = new System.Windows.Forms.Button();
            this.richTextBoxSendMsg = new System.Windows.Forms.RichTextBox();
            this.buttonStop = new System.Windows.Forms.Button();
            this.buttonAdvertise = new System.Windows.Forms.Button();
            this.contextMenuNotify = new System.Windows.Forms.ContextMenu();
            this.menuItemOpen = new System.Windows.Forms.MenuItem();
            this.menuItemAbout = new System.Windows.Forms.MenuItem();
            this.menuItem3 = new System.Windows.Forms.MenuItem();
            this.menuItemExit = new System.Windows.Forms.MenuItem();
            this.notifyIcon = new System.Windows.Forms.NotifyIcon(this.components);
            this.pictureBox1 = new System.Windows.Forms.PictureBox();
            ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).BeginInit();
            this.SuspendLayout();
            // 
            // richTextBoxRecieveMsg
            // 
            this.richTextBoxRecieveMsg.BackColor = System.Drawing.Color.WhiteSmoke;
            this.richTextBoxRecieveMsg.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
            this.richTextBoxRecieveMsg.Font = new System.Drawing.Font("Courier New", 9F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.richTextBoxRecieveMsg.Location = new System.Drawing.Point(7, 176);
            this.richTextBoxRecieveMsg.Name = "richTextBoxRecieveMsg";
            this.richTextBoxRecieveMsg.ReadOnly = true;
            this.richTextBoxRecieveMsg.ShowSelectionMargin = true;
            this.richTextBoxRecieveMsg.Size = new System.Drawing.Size(535, 218);
            this.richTextBoxRecieveMsg.TabIndex = 0;
            this.richTextBoxRecieveMsg.Text = "";
            // 
            // label1
            // 
            this.label1.AutoSize = true;
            this.label1.BackColor = System.Drawing.Color.Black;
            this.label1.Font = new System.Drawing.Font("Courier New", 9.75F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.label1.Location = new System.Drawing.Point(219, 27);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(80, 16);
            this.label1.TabIndex = 1;
            this.label1.Text = "User Name";
            // 
            // comboBoxUserNames
            // 
            this.comboBoxUserNames.BackColor = System.Drawing.Color.WhiteSmoke;
            this.comboBoxUserNames.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
            this.comboBoxUserNames.Location = new System.Drawing.Point(305, 25);
            this.comboBoxUserNames.Name = "comboBoxUserNames";
            this.comboBoxUserNames.Size = new System.Drawing.Size(152, 21);
            this.comboBoxUserNames.TabIndex = 2;
            // 
            // buttonSend
            // 
            this.buttonSend.BackColor = System.Drawing.Color.Black;
            this.buttonSend.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
            this.buttonSend.Font = new System.Drawing.Font("Courier New", 9.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.buttonSend.ForeColor = System.Drawing.Color.White;
            this.buttonSend.Location = new System.Drawing.Point(548, 409);
            this.buttonSend.Name = "buttonSend";
            this.buttonSend.Size = new System.Drawing.Size(72, 48);
            this.buttonSend.TabIndex = 3;
            this.buttonSend.Text = "Send";
            this.buttonSend.UseVisualStyleBackColor = false;
            this.buttonSend.Click += new System.EventHandler(this.buttonSend_Click);
            // 
            // richTextBoxSendMsg
            // 
            this.richTextBoxSendMsg.BackColor = System.Drawing.Color.WhiteSmoke;
            this.richTextBoxSendMsg.BorderStyle = System.Windows.Forms.BorderStyle.None;
            this.richTextBoxSendMsg.Font = new System.Drawing.Font("Microsoft Sans Serif", 9F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.richTextBoxSendMsg.Location = new System.Drawing.Point(7, 409);
            this.richTextBoxSendMsg.MaxLength = 500;
            this.richTextBoxSendMsg.Name = "richTextBoxSendMsg";
            this.richTextBoxSendMsg.ShowSelectionMargin = true;
            this.richTextBoxSendMsg.Size = new System.Drawing.Size(535, 48);
            this.richTextBoxSendMsg.TabIndex = 4;
            this.richTextBoxSendMsg.Text = "";
            // 
            // buttonStop
            // 
            this.buttonStop.BackColor = System.Drawing.Color.Black;
            this.buttonStop.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
            this.buttonStop.Font = new System.Drawing.Font("Courier New", 9.75F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.buttonStop.Location = new System.Drawing.Point(355, 73);
            this.buttonStop.Name = "buttonStop";
            this.buttonStop.Size = new System.Drawing.Size(100, 24);
            this.buttonStop.TabIndex = 5;
            this.buttonStop.Text = "Stop";
            this.buttonStop.UseVisualStyleBackColor = false;
            this.buttonStop.Click += new System.EventHandler(this.buttonStop_Click);
            // 
            // buttonAdvertise
            // 
            this.buttonAdvertise.BackColor = System.Drawing.Color.Black;
            this.buttonAdvertise.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
            this.buttonAdvertise.Font = new System.Drawing.Font("Courier New", 9.75F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.buttonAdvertise.Location = new System.Drawing.Point(249, 73);
            this.buttonAdvertise.Name = "buttonAdvertise";
            this.buttonAdvertise.Size = new System.Drawing.Size(100, 24);
            this.buttonAdvertise.TabIndex = 6;
            this.buttonAdvertise.Text = "Advertise";
            this.buttonAdvertise.UseVisualStyleBackColor = false;
            this.buttonAdvertise.Click += new System.EventHandler(this.buttonAdvertise_Click);
            // 
            // contextMenuNotify
            // 
            this.contextMenuNotify.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
            this.menuItemOpen,
            this.menuItemAbout,
            this.menuItem3,
            this.menuItemExit});
            // 
            // menuItemOpen
            // 
            this.menuItemOpen.Index = 0;
            this.menuItemOpen.Text = "Open";
            this.menuItemOpen.Click += new System.EventHandler(this.menuItemOpen_Click);
            // 
            // menuItemAbout
            // 
            this.menuItemAbout.Index = 1;
            this.menuItemAbout.Text = "About LanChat";
            this.menuItemAbout.Click += new System.EventHandler(this.menuItemAbout_Click);
            // 
            // menuItem3
            // 
            this.menuItem3.Index = 2;
            this.menuItem3.Text = "-";
            // 
            // menuItemExit
            // 
            this.menuItemExit.Index = 3;
            this.menuItemExit.Text = "Exit";
            this.menuItemExit.Click += new System.EventHandler(this.menuItemExit_Click);
            // 
            // notifyIcon
            // 
            this.notifyIcon.ContextMenu = this.contextMenuNotify;
            this.notifyIcon.Text = "notifyIcon";
            this.notifyIcon.Visible = true;
            this.notifyIcon.DoubleClick += new System.EventHandler(this.notifyIcon_DoubleClick);
            // 
            // pictureBox1
            // 
            this.pictureBox1.Image = global::LanChat.Properties.Resources.forweb;
            this.pictureBox1.Location = new System.Drawing.Point(12, 12);
            this.pictureBox1.Name = "pictureBox1";
            this.pictureBox1.Size = new System.Drawing.Size(201, 151);
            this.pictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.Zoom;
            this.pictureBox1.TabIndex = 7;
            this.pictureBox1.TabStop = false;
            // 
            // LanChat
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.BackColor = System.Drawing.Color.Black;
            this.ClientSize = new System.Drawing.Size(632, 469);
            this.Controls.Add(this.pictureBox1);
            this.Controls.Add(this.buttonAdvertise);
            this.Controls.Add(this.buttonStop);
            this.Controls.Add(this.richTextBoxRecieveMsg);
            this.Controls.Add(this.richTextBoxSendMsg);
            this.Controls.Add(this.buttonSend);
            this.Controls.Add(this.comboBoxUserNames);
            this.Controls.Add(this.label1);
            this.ForeColor = System.Drawing.Color.White;
            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
            this.MaximizeBox = false;
            this.Name = "LanChat";
            this.ShowInTaskbar = false;
            this.Text = "Chat";
            this.Closing += new System.ComponentModel.CancelEventHandler(this.Form1_Closing);
            ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).EndInit();
            this.ResumeLayout(false);
            this.PerformLayout();
 
		}
		#endregion
		[STAThread]
		static void Main() 
		{
			LanChat f = new LanChat();
			Application.Run(f);
		}
        public void buttonSend_Click(object sender, EventArgs e)
		{
			if(richTextBoxSendMsg.Text == "")
				return;
			String message = "MSG:$" + GetUserName() +" : " + richTextBoxSendMsg.Text;
			string []host = comboBoxUserNames.Text.Split('\\');
			if(host.Length >1)
			{
				string hostName = Dns.GetHostByName(host[0]).AddressList[0].ToString();
				MulticastSend(hostName, 1000, message);
				richTextBoxSendMsg.Text = "";
			}
		}
        public void buttonAdvertise_Click(object sender, System.EventArgs e)
		{
			String message = "Hello$"  + GetUserName();
			MulticastSend("224.168.100.2", 1000, message);
		}
        public void buttonStop_Click(object sender, System.EventArgs e)
		{
			String message = "Stop$"  + GetUserName();
			MulticastSend("224.168.100.2", 1000, message);
		}
        public void Form1_Closing(object sender, System.ComponentModel.CancelEventArgs e)
		{
			rwl.AcquireWriterLock(10);
			IsThreadRunning = false;
			rwl.ReleaseWriterLock();
			thread.Abort();
		}
        public void MulticastListener()
		{
			recv("224.168.100.2", "1000");
            this.Controls.Add(this.comboBoxUserNames);
 
		}
        public void MulticastSend(string mAddress, int port, string message)
		{
			try 
			{
				IPAddress GroupAddress = IPAddress.Parse(mAddress);
				int GroupPort = port;
				UdpClient sender = new UdpClient();
				IPEndPoint groupEP = new IPEndPoint(GroupAddress,GroupPort);
				byte[] bytes = Encoding.ASCII.GetBytes(message);
				sender.Send(bytes, bytes.Length, groupEP);
				sender.Close();
    		} 
			catch (Exception e) 
			{
				MessageBox.Show(e.ToString());
			}
		}
		void recv(string mcastGroup, string port) 
		{
			Socket s=new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
			IPEndPoint ipep=new IPEndPoint(IPAddress.Any,int.Parse(port));
			s.Bind(ipep);
			IPAddress ip=IPAddress.Parse(mcastGroup);
			s.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.AddMembership, new MulticastOption(ip,IPAddress.Any));
			IsThreadRunning = true;
			while(IsThreadRunning) 
			{
				byte[] b=new byte[500];
				s.Receive(b);
				string str = System.Text.Encoding.ASCII.GetString(b,0,b.Length);
				str = str.Replace("\0","");
				if(str.StartsWith("Hello"))
				{
					string []array = str.Split('$');
					if(array.Length > 1)
					{
						if(!userList.Contains(array[1].ToString()))
						{
							userList.Add(array[1]);
							UpdateComboBox();
 
						}
					}
				}
				else if(str.StartsWith("Stop"))
				{
					string []array = str.Split('$');
					if(array.Length > 1)
					{
						if(userList.Contains(array[1].ToString()))
						{
							userList.Remove(array[1]);
 
							UpdateComboBox();
						}
					}
				}
				else if(str.StartsWith("MSG:"))
				{
					str = str.Replace("MSG:$", "");
					int start = this.richTextBoxRecieveMsg.TextLength;
					int length = str.IndexOf(':');
					richTextBoxRecieveMsg.AppendText(str + "\n");
					if(start >= 0 && start < richTextBoxRecieveMsg.TextLength && length > 0 && length + start < richTextBoxRecieveMsg.TextLength)
					{
						this.richTextBoxRecieveMsg.Select(start, length);
						this.richTextBoxRecieveMsg.SelectionColor = Color.Blue;
						this.richTextBoxRecieveMsg.SelectionLength = 0;
					}
				}
			}
		}
		public void UpdateComboBox()
		{
			comboBoxUserNames.Items.Clear();
			comboBoxUserNames.Items.AddRange(userList.ToArray());
		}
		string GetUserName()
		{
			string str;
			str = System.Security.Principal.WindowsIdentity.GetCurrent().Name.ToString();
			return str;
		}
		Icon LoadIcon()
		{
			Assembly assembly = typeof(LanChat).Assembly;
			string Name = "LanChat.LanChat.ico";
			return new Icon(assembly.GetManifestResourceStream(Name));
		}
        public void notifyIcon_DoubleClick(object sender, System.EventArgs e)
		{
			if (this.WindowState == FormWindowState.Minimized)
				this.WindowState = FormWindowState.Normal;
			this.Activate();
		}
        public void menuItemOpen_Click(object sender, System.EventArgs e)
		{
			this.Activate();
		}
        public void menuItemAbout_Click(object sender, System.EventArgs e)
		{
			About about = new About();
			about.Location =  Control.MousePosition;
			about.Show();
		}
        public void menuItemExit_Click(object sender, System.EventArgs e)
		{
			this.Close();
		}
	}
}
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Text;
using System.Security.Principal;
using System.Reflection;

namespace LanChat
{
	public class LanChat : System.Windows.Forms.Form
	{
		Thread thread;
		bool IsThreadRunning = false;
		ReaderWriterLock rwl = new ReaderWriterLock();
		ArrayList userList = new ArrayList();
		
		public System.Windows.Forms.RichTextBox richTextBoxRecieveMsg;
        public System.Windows.Forms.Label label1;
        public System.Windows.Forms.ComboBox comboBoxUserNames;
        public System.Windows.Forms.RichTextBox richTextBoxSendMsg;
        public System.Windows.Forms.Button buttonStop;
        public System.Windows.Forms.Button buttonAdvertise;
        public System.Windows.Forms.Button buttonSend;
        public System.Windows.Forms.ContextMenu contextMenuNotify;
        public System.Windows.Forms.MenuItem menuItem3;
        public System.Windows.Forms.MenuItem menuItemExit;
        public System.Windows.Forms.MenuItem menuItemOpen;
        public System.Windows.Forms.MenuItem menuItemAbout;
        public System.Windows.Forms.NotifyIcon notifyIcon;
        public PictureBox pictureBox1;
        public System.ComponentModel.IContainer components;
	
		public LanChat()
		{
			InitializeComponent();
			thread = new Thread(new ThreadStart(MulticastListener));
			thread.Start();
			String message = "Hello$"  + GetUserName();
			MulticastSend("224.168.100.2", 1000, message);
			notifyIcon.Icon = LoadIcon();
			this.Icon = LoadIcon();
		}
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if (components != null) 
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}
		#region Windows Form Designer generated code
		private void InitializeComponent()
		{
            this.components = new System.ComponentModel.Container();
            this.richTextBoxRecieveMsg = new System.Windows.Forms.RichTextBox();
            this.label1 = new System.Windows.Forms.Label();
            this.comboBoxUserNames = new System.Windows.Forms.ComboBox();
            this.buttonSend = new System.Windows.Forms.Button();
            this.richTextBoxSendMsg = new System.Windows.Forms.RichTextBox();
            this.buttonStop = new System.Windows.Forms.Button();
            this.buttonAdvertise = new System.Windows.Forms.Button();
            this.contextMenuNotify = new System.Windows.Forms.ContextMenu();
            this.menuItemOpen = new System.Windows.Forms.MenuItem();
            this.menuItemAbout = new System.Windows.Forms.MenuItem();
            this.menuItem3 = new System.Windows.Forms.MenuItem();
            this.menuItemExit = new System.Windows.Forms.MenuItem();
            this.notifyIcon = new System.Windows.Forms.NotifyIcon(this.components);
            this.pictureBox1 = new System.Windows.Forms.PictureBox();
            ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).BeginInit();
            this.SuspendLayout();
            // 
            // richTextBoxRecieveMsg
            // 
            this.richTextBoxRecieveMsg.BackColor = System.Drawing.Color.WhiteSmoke;
            this.richTextBoxRecieveMsg.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
            this.richTextBoxRecieveMsg.Font = new System.Drawing.Font("Courier New", 9F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.richTextBoxRecieveMsg.Location = new System.Drawing.Point(7, 176);
            this.richTextBoxRecieveMsg.Name = "richTextBoxRecieveMsg";
            this.richTextBoxRecieveMsg.ReadOnly = true;
            this.richTextBoxRecieveMsg.ShowSelectionMargin = true;
            this.richTextBoxRecieveMsg.Size = new System.Drawing.Size(535, 218);
            this.richTextBoxRecieveMsg.TabIndex = 0;
            this.richTextBoxRecieveMsg.Text = "";
            // 
            // label1
            // 
            this.label1.AutoSize = true;
            this.label1.BackColor = System.Drawing.Color.Black;
            this.label1.Font = new System.Drawing.Font("Courier New", 9.75F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.label1.Location = new System.Drawing.Point(219, 27);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(80, 16);
            this.label1.TabIndex = 1;
            this.label1.Text = "User Name";
            // 
            // comboBoxUserNames
            // 
            this.comboBoxUserNames.BackColor = System.Drawing.Color.WhiteSmoke;
            this.comboBoxUserNames.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
            this.comboBoxUserNames.Location = new System.Drawing.Point(305, 25);
            this.comboBoxUserNames.Name = "comboBoxUserNames";
            this.comboBoxUserNames.Size = new System.Drawing.Size(152, 21);
            this.comboBoxUserNames.TabIndex = 2;
            // 
            // buttonSend
            // 
            this.buttonSend.BackColor = System.Drawing.Color.Black;
            this.buttonSend.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
            this.buttonSend.Font = new System.Drawing.Font("Courier New", 9.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.buttonSend.ForeColor = System.Drawing.Color.White;
            this.buttonSend.Location = new System.Drawing.Point(548, 409);
            this.buttonSend.Name = "buttonSend";
            this.buttonSend.Size = new System.Drawing.Size(72, 48);
            this.buttonSend.TabIndex = 3;
            this.buttonSend.Text = "Send";
            this.buttonSend.UseVisualStyleBackColor = false;
            this.buttonSend.Click += new System.EventHandler(this.buttonSend_Click);
            // 
            // richTextBoxSendMsg
            // 
            this.richTextBoxSendMsg.BackColor = System.Drawing.Color.WhiteSmoke;
            this.richTextBoxSendMsg.BorderStyle = System.Windows.Forms.BorderStyle.None;
            this.richTextBoxSendMsg.Font = new System.Drawing.Font("Microsoft Sans Serif", 9F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.richTextBoxSendMsg.Location = new System.Drawing.Point(7, 409);
            this.richTextBoxSendMsg.MaxLength = 500;
            this.richTextBoxSendMsg.Name = "richTextBoxSendMsg";
            this.richTextBoxSendMsg.ShowSelectionMargin = true;
            this.richTextBoxSendMsg.Size = new System.Drawing.Size(535, 48);
            this.richTextBoxSendMsg.TabIndex = 4;
            this.richTextBoxSendMsg.Text = "";
            // 
            // buttonStop
            // 
            this.buttonStop.BackColor = System.Drawing.Color.Black;
            this.buttonStop.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
            this.buttonStop.Font = new System.Drawing.Font("Courier New", 9.75F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.buttonStop.Location = new System.Drawing.Point(355, 73);
            this.buttonStop.Name = "buttonStop";
            this.buttonStop.Size = new System.Drawing.Size(100, 24);
            this.buttonStop.TabIndex = 5;
            this.buttonStop.Text = "Stop";
            this.buttonStop.UseVisualStyleBackColor = false;
            this.buttonStop.Click += new System.EventHandler(this.buttonStop_Click);
            // 
            // buttonAdvertise
            // 
            this.buttonAdvertise.BackColor = System.Drawing.Color.Black;
            this.buttonAdvertise.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
            this.buttonAdvertise.Font = new System.Drawing.Font("Courier New", 9.75F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.buttonAdvertise.Location = new System.Drawing.Point(249, 73);
            this.buttonAdvertise.Name = "buttonAdvertise";
            this.buttonAdvertise.Size = new System.Drawing.Size(100, 24);
            this.buttonAdvertise.TabIndex = 6;
            this.buttonAdvertise.Text = "Advertise";
            this.buttonAdvertise.UseVisualStyleBackColor = false;
            this.buttonAdvertise.Click += new System.EventHandler(this.buttonAdvertise_Click);
            // 
            // contextMenuNotify
            // 
            this.contextMenuNotify.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
            this.menuItemOpen,
            this.menuItemAbout,
            this.menuItem3,
            this.menuItemExit});
            // 
            // menuItemOpen
            // 
            this.menuItemOpen.Index = 0;
            this.menuItemOpen.Text = "Open";
            this.menuItemOpen.Click += new System.EventHandler(this.menuItemOpen_Click);
            // 
            // menuItemAbout
            // 
            this.menuItemAbout.Index = 1;
            this.menuItemAbout.Text = "About LanChat";
            this.menuItemAbout.Click += new System.EventHandler(this.menuItemAbout_Click);
            // 
            // menuItem3
            // 
            this.menuItem3.Index = 2;
            this.menuItem3.Text = "-";
            // 
            // menuItemExit
            // 
            this.menuItemExit.Index = 3;
            this.menuItemExit.Text = "Exit";
            this.menuItemExit.Click += new System.EventHandler(this.menuItemExit_Click);
            // 
            // notifyIcon
            // 
            this.notifyIcon.ContextMenu = this.contextMenuNotify;
            this.notifyIcon.Text = "notifyIcon";
            this.notifyIcon.Visible = true;
            this.notifyIcon.DoubleClick += new System.EventHandler(this.notifyIcon_DoubleClick);
            // 
            // pictureBox1
            // 
            this.pictureBox1.Image = global::LanChat.Properties.Resources.forweb;
            this.pictureBox1.Location = new System.Drawing.Point(12, 12);
            this.pictureBox1.Name = "pictureBox1";
            this.pictureBox1.Size = new System.Drawing.Size(201, 151);
            this.pictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.Zoom;
            this.pictureBox1.TabIndex = 7;
            this.pictureBox1.TabStop = false;
            // 
            // LanChat
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.BackColor = System.Drawing.Color.Black;
            this.ClientSize = new System.Drawing.Size(632, 469);
            this.Controls.Add(this.pictureBox1);
            this.Controls.Add(this.buttonAdvertise);
            this.Controls.Add(this.buttonStop);
            this.Controls.Add(this.richTextBoxRecieveMsg);
            this.Controls.Add(this.richTextBoxSendMsg);
            this.Controls.Add(this.buttonSend);
            this.Controls.Add(this.comboBoxUserNames);
            this.Controls.Add(this.label1);
            this.ForeColor = System.Drawing.Color.White;
            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
            this.MaximizeBox = false;
            this.Name = "LanChat";
            this.ShowInTaskbar = false;
            this.Text = "Chat";
            this.Closing += new System.ComponentModel.CancelEventHandler(this.Form1_Closing);
            ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).EndInit();
            this.ResumeLayout(false);
            this.PerformLayout();

		}
		#endregion
		[STAThread]
		static void Main() 
		{
			LanChat f = new LanChat();
			Application.Run(f);
		}
        public void buttonSend_Click(object sender, EventArgs e)
		{
			if(richTextBoxSendMsg.Text == "")
				return;
			String message = "MSG:$" + GetUserName() +" : " + richTextBoxSendMsg.Text;
			string []host = comboBoxUserNames.Text.Split('\\');
			if(host.Length >1)
			{
				string hostName = Dns.GetHostByName(host[0]).AddressList[0].ToString();
				MulticastSend(hostName, 1000, message);
				richTextBoxSendMsg.Text = "";
			}
		}
        public void buttonAdvertise_Click(object sender, System.EventArgs e)
		{
			String message = "Hello$"  + GetUserName();
			MulticastSend("224.168.100.2", 1000, message);
		}
        public void buttonStop_Click(object sender, System.EventArgs e)
		{
			String message = "Stop$"  + GetUserName();
			MulticastSend("224.168.100.2", 1000, message);
		}
        public void Form1_Closing(object sender, System.ComponentModel.CancelEventArgs e)
		{
			rwl.AcquireWriterLock(10);
			IsThreadRunning = false;
			rwl.ReleaseWriterLock();
			thread.Abort();
		}
        public void MulticastListener()
		{
			recv("224.168.100.2", "1000");
            this.Controls.Add(this.comboBoxUserNames);

		}
        public void MulticastSend(string mAddress, int port, string message)
		{
			try 
			{
				IPAddress GroupAddress = IPAddress.Parse(mAddress);
				int GroupPort = port;
				UdpClient sender = new UdpClient();
				IPEndPoint groupEP = new IPEndPoint(GroupAddress,GroupPort);
				byte[] bytes = Encoding.ASCII.GetBytes(message);
				sender.Send(bytes, bytes.Length, groupEP);
				sender.Close();
    		} 
			catch (Exception e) 
			{
				MessageBox.Show(e.ToString());
			}
		}
		void recv(string mcastGroup, string port) 
		{
			Socket s=new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
			IPEndPoint ipep=new IPEndPoint(IPAddress.Any,int.Parse(port));
			s.Bind(ipep);
			IPAddress ip=IPAddress.Parse(mcastGroup);
			s.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.AddMembership, new MulticastOption(ip,IPAddress.Any));
			IsThreadRunning = true;
			while(IsThreadRunning) 
			{
				byte[] b=new byte[500];
				s.Receive(b);
				string str = System.Text.Encoding.ASCII.GetString(b,0,b.Length);
				str = str.Replace("\0","");
				if(str.StartsWith("Hello"))
				{
					string []array = str.Split('$');
					if(array.Length > 1)
					{
						if(!userList.Contains(array[1].ToString()))
						{
							userList.Add(array[1]);
							UpdateComboBox();
                           
						}
					}
				}
				else if(str.StartsWith("Stop"))
				{
					string []array = str.Split('$');
					if(array.Length > 1)
					{
						if(userList.Contains(array[1].ToString()))
						{
							userList.Remove(array[1]);
                          
							UpdateComboBox();
						}
					}
				}
				else if(str.StartsWith("MSG:"))
				{
					str = str.Replace("MSG:$", "");
					int start = this.richTextBoxRecieveMsg.TextLength;
					int length = str.IndexOf(':');
					richTextBoxRecieveMsg.AppendText(str + "\n");
					if(start >= 0 && start < richTextBoxRecieveMsg.TextLength && length > 0 && length + start < richTextBoxRecieveMsg.TextLength)
					{
						this.richTextBoxRecieveMsg.Select(start, length);
						this.richTextBoxRecieveMsg.SelectionColor = Color.Blue;
						this.richTextBoxRecieveMsg.SelectionLength = 0;
					}
				}
			}
		}
		public void UpdateComboBox()
		{
			comboBoxUserNames.Items.Clear();
			comboBoxUserNames.Items.AddRange(userList.ToArray());
		}
		string GetUserName()
		{
			string str;
			str = System.Security.Principal.WindowsIdentity.GetCurrent().Name.ToString();
			return str;
		}
		Icon LoadIcon()
		{
			Assembly assembly = typeof(LanChat).Assembly;
			string Name = "LanChat.LanChat.ico";
			return new Icon(assembly.GetManifestResourceStream(Name));
		}
        public void notifyIcon_DoubleClick(object sender, System.EventArgs e)
		{
			if (this.WindowState == FormWindowState.Minimized)
				this.WindowState = FormWindowState.Normal;
			this.Activate();
		}
        public void menuItemOpen_Click(object sender, System.EventArgs e)
		{
			this.Activate();
		}
        public void menuItemAbout_Click(object sender, System.EventArgs e)
		{
			About about = new About();
			about.Location =  Control.MousePosition;
			about.Show();
		}
        public void menuItemExit_Click(object sender, System.EventArgs e)
		{
			this.Close();
		}
	}
}

Need any more information on this question please ask...

"By the data to date, there is only one animal in the Galaxy dangerous to man—man himself. So he must supply his own indispensable competition. He has no enemy to help him."
From Time Enough for Love by Robert A. Heinlein

•

Join Date: Apr 2005

Posts: 15,990

Reputation: jbennet is a name known to all

Solved Threads: 510

jbennet

Online

Moderator

Re: Thread's colliding?

Nov 25th, 2007

you need to use the threadworker object

If i am helpful, please give me reputation points.

•

Join Date: Dec 2005

Posts: 45

Reputation: _r0ckbaer is an unknown quantity at this point

Solved Threads: 7

_r0ckbaer

Offline

Light Poster

Re: Thread's colliding?

Nov 25th, 2007

Here is corrected source:

 Help with Code Tags 
 C# Syntax (Toggle Plain Text) 
using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Net;
using System.Net.Sockets;
using System.Reflection;
using System.Security.Principal;
using System.Text;
using System.Threading;
using System.Windows.Forms;
 
namespace LanChat
{
    public class LanChat : Form
    {
        public Button buttonAdvertise;
        public Button buttonSend;
        public Button buttonStop;
        public ComboBox comboBoxUserNames;
        public IContainer components;
        public ContextMenu contextMenuNotify;
        private bool IsThreadRunning = false;
        public Label label1;
        public MenuItem menuItem3;
        public MenuItem menuItemAbout;
        public MenuItem menuItemExit;
        public MenuItem menuItemOpen;
        public NotifyIcon notifyIcon;
        public PictureBox pictureBox1;
        public RichTextBox richTextBoxRecieveMsg;
        public RichTextBox richTextBoxSendMsg;
        private ReaderWriterLock rwl = new ReaderWriterLock();
        private Thread thread;
        private ArrayList userList = new ArrayList();
 
        public LanChat()
        {
            InitializeComponent();
            thread = new Thread(new ThreadStart(MulticastListener));
            thread.Start();
            String message = "Hello$" + GetUserName();
            MulticastSend("224.168.100.2", 1000, message);
            notifyIcon.Icon = LoadIcon();
            Icon = LoadIcon();
        }
 
        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                if (components != null)
                {
                    components.Dispose();
                }
            }
            base.Dispose(disposing);
        }
 
        [STAThread]
        private static void Main()
        {
            LanChat f = new LanChat();
            Application.Run(f);
        }
 
        public void buttonSend_Click(object sender, EventArgs e)
        {
            if (richTextBoxSendMsg.Text == "")
                return;
            String message = "MSG:$" + GetUserName() + " : " + richTextBoxSendMsg.Text;
            string[] host = comboBoxUserNames.Text.Split('\\');
            if (host.Length > 1)
            {
                string hostName = Dns.GetHostByName(host[0]).AddressList[0].ToString();
                MulticastSend(hostName, 1000, message);
                richTextBoxSendMsg.Text = "";
            }
        }
 
        public void buttonAdvertise_Click(object sender, EventArgs e)
        {
            String message = "Hello$" + GetUserName();
            MulticastSend("224.168.100.2", 1000, message);
        }
 
        public void buttonStop_Click(object sender, EventArgs e)
        {
            String message = "Stop$" + GetUserName();
            MulticastSend("224.168.100.2", 1000, message);
        }
 
        public void Form1_Closing(object sender, CancelEventArgs e)
        {
            rwl.AcquireWriterLock(10);
            IsThreadRunning = false;
            rwl.ReleaseWriterLock();
            thread.Abort();
        }
 
        public void MulticastListener()
        {
            recv("224.168.100.2", "1000");
            Controls.Add(comboBoxUserNames);
        }
 
        public void MulticastSend(string mAddress, int port, string message)
        {
            try
            {
                IPAddress GroupAddress = IPAddress.Parse(mAddress);
                int GroupPort = port;
                UdpClient sender = new UdpClient();
                IPEndPoint groupEP = new IPEndPoint(GroupAddress, GroupPort);
                byte[] bytes = Encoding.ASCII.GetBytes(message);
                sender.Send(bytes, bytes.Length, groupEP);
                sender.Close();
            }
            catch (Exception e)
            {
                MessageBox.Show(e.ToString());
            }
        }
 
        private void recv(string mcastGroup, string port)
        {
            Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
            IPEndPoint ipep = new IPEndPoint(IPAddress.Any, int.Parse(port));
            s.Bind(ipep);
            IPAddress ip = IPAddress.Parse(mcastGroup);
            s.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.AddMembership,
                              new MulticastOption(ip, IPAddress.Any));
            IsThreadRunning = true;
            while (IsThreadRunning)
            {
                byte[] b = new byte[500];
                s.Receive(b);
                string str = Encoding.ASCII.GetString(b, 0, b.Length);
                str = str.Replace("\0", "");
                if (str.StartsWith("Hello"))
                {
                    string[] array = str.Split('$');
                    if (array.Length > 1)
                    {
                        if (!userList.Contains(array[1].ToString()))
                        {
                            userList.Add(array[1]);
                            UpdateComboBox();
                        }
                    }
                }
                else if (str.StartsWith("Stop"))
                {
                    string[] array = str.Split('$');
                    if (array.Length > 1)
                    {
                        if (userList.Contains(array[1].ToString()))
                        {
                            userList.Remove(array[1]);
 
                            if (comboBoxUserNames.InvokeRequired)
                            {
                                comboBoxUserNames.Invoke(new UpdateComboBoxHandler(UpdateComboBox));
                            }
                            else
                            {
                                UpdateComboBox();
                            }
                        }
                    }
                }
                else if (str.StartsWith("MSG:"))
                {
                    int start = -1;
                    int length = -1;
                    if (richTextBoxRecieveMsg.InvokeRequired)
                    {
                        if (richTextBoxRecieveMsg.InvokeRequired)
                            richTextBoxSendMsg.Invoke(new SetStartHandler(UpdateControl), new object[] {start, str, length});
                    }
                    else
                    {
                        UpdateControl(ref start, ref str, ref length);
                    }
                }
            }
        }
 
        private delegate void UpdateComboBoxHandler();
        private delegate void SetStartHandler(ref int start, ref string str, ref int length);
        private void UpdateControl(ref int start, ref string str, ref int length)
        {
            str = str.Replace("MSG:$", "");
            start = richTextBoxSendMsg.TextLength;
            length = str.IndexOf(':');
            richTextBoxRecieveMsg.AppendText(str + "\n");
            if (start >= 0 && start < richTextBoxRecieveMsg.TextLength && length > 0 &&
                length + start < richTextBoxRecieveMsg.TextLength)
            {
                richTextBoxRecieveMsg.Select(start, length);
                richTextBoxRecieveMsg.SelectionColor = Color.Blue;
                richTextBoxRecieveMsg.SelectionLength = 0;
            }
        }
 
        public void UpdateComboBox()
        {
            comboBoxUserNames.Items.Clear();
            comboBoxUserNames.Items.AddRange(userList.ToArray());
        }
 
        private string GetUserName()
        {
            string str;
            str = WindowsIdentity.GetCurrent().Name.ToString();
            return str;
        }
 
        private Icon LoadIcon()
        {
            Assembly assembly = typeof (LanChat).Assembly;
            string Name = "LanChat.LanChat.ico";
            return null;
        }
 
        public void notifyIcon_DoubleClick(object sender, EventArgs e)
        {
            if (WindowState == FormWindowState.Minimized)
                WindowState = FormWindowState.Normal;
            Activate();
        }
 
        public void menuItemOpen_Click(object sender, EventArgs e)
        {
            Activate();
        }
 
        public void menuItemAbout_Click(object sender, EventArgs e)
        {
//            About about = new About();
//            about.Location = MousePosition;
//            about.Show();
        }
 
        public void menuItemExit_Click(object sender, EventArgs e)
        {
            Close();
        }
 
        #region Windows Form Designer generated code
 
        private void InitializeComponent()
        {
            this.components = new System.ComponentModel.Container();
            this.richTextBoxRecieveMsg = new System.Windows.Forms.RichTextBox();
            this.label1 = new System.Windows.Forms.Label();
            this.comboBoxUserNames = new System.Windows.Forms.ComboBox();
            this.buttonSend = new System.Windows.Forms.Button();
            this.richTextBoxSendMsg = new System.Windows.Forms.RichTextBox();
            this.buttonStop = new System.Windows.Forms.Button();
            this.buttonAdvertise = new System.Windows.Forms.Button();
            this.contextMenuNotify = new System.Windows.Forms.ContextMenu();
            this.menuItemOpen = new System.Windows.Forms.MenuItem();
            this.menuItemAbout = new System.Windows.Forms.MenuItem();
            this.menuItem3 = new System.Windows.Forms.MenuItem();
            this.menuItemExit = new System.Windows.Forms.MenuItem();
            this.notifyIcon = new System.Windows.Forms.NotifyIcon(this.components);
            this.pictureBox1 = new System.Windows.Forms.PictureBox();
            ((System.ComponentModel.ISupportInitialize) (this.pictureBox1)).BeginInit();
            this.SuspendLayout();
            // 
            // richTextBoxRecieveMsg
            // 
            this.richTextBoxRecieveMsg.BackColor = System.Drawing.Color.WhiteSmoke;
            this.richTextBoxRecieveMsg.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
            this.richTextBoxRecieveMsg.Font =
                new System.Drawing.Font("Courier New", 9F, System.Drawing.FontStyle.Regular,
                                        System.Drawing.GraphicsUnit.Point, ((byte) (0)));
            this.richTextBoxRecieveMsg.Location = new System.Drawing.Point(7, 176);
            this.richTextBoxRecieveMsg.Name = "richTextBoxRecieveMsg";
            this.richTextBoxRecieveMsg.ReadOnly = true;
            this.richTextBoxRecieveMsg.ShowSelectionMargin = true;
            this.richTextBoxRecieveMsg.Size = new System.Drawing.Size(535, 218);
            this.richTextBoxRecieveMsg.TabIndex = 0;
            this.richTextBoxRecieveMsg.Text = "";
            // 
            // label1
            // 
            this.label1.AutoSize = true;
            this.label1.BackColor = System.Drawing.Color.Black;
            this.label1.Font =
                new System.Drawing.Font("Courier New", 9.75F, System.Drawing.FontStyle.Regular,
                                        System.Drawing.GraphicsUnit.Point, ((byte) (0)));
            this.label1.Location = new System.Drawing.Point(219, 27);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(80, 16);
            this.label1.TabIndex = 1;
            this.label1.Text = "User Name";
            // 
            // comboBoxUserNames
            // 
            this.comboBoxUserNames.BackColor = System.Drawing.Color.WhiteSmoke;
            this.comboBoxUserNames.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
            this.comboBoxUserNames.Location = new System.Drawing.Point(305, 25);
            this.comboBoxUserNames.Name = "comboBoxUserNames";
            this.comboBoxUserNames.Size = new System.Drawing.Size(152, 21);
            this.comboBoxUserNames.TabIndex = 2;
            // 
            // buttonSend
            // 
            this.buttonSend.BackColor = System.Drawing.Color.Black;
            this.buttonSend.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
            this.buttonSend.Font =
                new System.Drawing.Font("Courier New", 9.75F, System.Drawing.FontStyle.Bold,
                                        System.Drawing.GraphicsUnit.Point, ((byte) (0)));
            this.buttonSend.ForeColor = System.Drawing.Color.White;
            this.buttonSend.Location = new System.Drawing.Point(548, 409);
            this.buttonSend.Name = "buttonSend";
            this.buttonSend.Size = new System.Drawing.Size(72, 48);
            this.buttonSend.TabIndex = 3;
            this.buttonSend.Text = "Send";
            this.buttonSend.UseVisualStyleBackColor = false;
            this.buttonSend.Click += new System.EventHandler(this.buttonSend_Click);
            // 
            // richTextBoxSendMsg
            // 
            this.richTextBoxSendMsg.BackColor = System.Drawing.Color.WhiteSmoke;
            this.richTextBoxSendMsg.BorderStyle = System.Windows.Forms.BorderStyle.None;
            this.richTextBoxSendMsg.Font =
                new System.Drawing.Font("Microsoft Sans Serif", 9F, System.Drawing.FontStyle.Regular,
                                        System.Drawing.GraphicsUnit.Point, ((byte) (0)));
            this.richTextBoxSendMsg.Location = new System.Drawing.Point(7, 409);
            this.richTextBoxSendMsg.MaxLength = 500;
            this.richTextBoxSendMsg.Name = "richTextBoxSendMsg";
            this.richTextBoxSendMsg.ShowSelectionMargin = true;
            this.richTextBoxSendMsg.Size = new System.Drawing.Size(535, 48);
            this.richTextBoxSendMsg.TabIndex = 4;
            this.richTextBoxSendMsg.Text = "";
            // 
            // buttonStop
            // 
            this.buttonStop.BackColor = System.Drawing.Color.Black;
            this.buttonStop.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
            this.buttonStop.Font =
                new System.Drawing.Font("Courier New", 9.75F, System.Drawing.FontStyle.Regular,
                                        System.Drawing.GraphicsUnit.Point, ((byte) (0)));
            this.buttonStop.Location = new System.Drawing.Point(355, 73);
            this.buttonStop.Name = "buttonStop";
            this.buttonStop.Size = new System.Drawing.Size(100, 24);
            this.buttonStop.TabIndex = 5;
            this.buttonStop.Text = "Stop";
            this.buttonStop.UseVisualStyleBackColor = false;
            this.buttonStop.Click += new System.EventHandler(this.buttonStop_Click);
            // 
            // buttonAdvertise
            // 
            this.buttonAdvertise.BackColor = System.Drawing.Color.Black;
            this.buttonAdvertise.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
            this.buttonAdvertise.Font =
                new System.Drawing.Font("Courier New", 9.75F, System.Drawing.FontStyle.Regular,
                                        System.Drawing.GraphicsUnit.Point, ((byte) (0)));
            this.buttonAdvertise.Location = new System.Drawing.Point(249, 73);
            this.buttonAdvertise.Name = "buttonAdvertise";
            this.buttonAdvertise.Size = new System.Drawing.Size(100, 24);
            this.buttonAdvertise.TabIndex = 6;
            this.buttonAdvertise.Text = "Advertise";
            this.buttonAdvertise.UseVisualStyleBackColor = false;
            this.buttonAdvertise.Click += new System.EventHandler(this.buttonAdvertise_Click);
            // 
            // contextMenuNotify
            // 
            this.contextMenuNotify.MenuItems.AddRange(new System.Windows.Forms.MenuItem[]
                                                          {
                                                              this.menuItemOpen,
                                                              this.menuItemAbout,
                                                              this.menuItem3,
                                                              this.menuItemExit
                                                          });
            // 
            // menuItemOpen
            // 
            this.menuItemOpen.Index = 0;
            this.menuItemOpen.Text = "Open";
            this.menuItemOpen.Click += new System.EventHandler(this.menuItemOpen_Click);
            // 
            // menuItemAbout
            // 
            this.menuItemAbout.Index = 1;
            this.menuItemAbout.Text = "About LanChat";
            this.menuItemAbout.Click += new System.EventHandler(this.menuItemAbout_Click);
            // 
            // menuItem3
            // 
            this.menuItem3.Index = 2;
            this.menuItem3.Text = "-";
            // 
            // menuItemExit
            // 
            this.menuItemExit.Index = 3;
            this.menuItemExit.Text = "Exit";
            this.menuItemExit.Click += new System.EventHandler(this.menuItemExit_Click);
            // 
            // notifyIcon
            // 
            this.notifyIcon.ContextMenu = this.contextMenuNotify;
            this.notifyIcon.Text = "notifyIcon";
            this.notifyIcon.Visible = true;
            this.notifyIcon.DoubleClick += new System.EventHandler(this.notifyIcon_DoubleClick);
            // 
            // pictureBox1
            // 
//            this.pictureBox1.Image = global::LanChat.Properties.Resources.forweb;
            this.pictureBox1.Location = new System.Drawing.Point(12, 12);
            this.pictureBox1.Name = "pictureBox1";
            this.pictureBox1.Size = new System.Drawing.Size(201, 151);
            this.pictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.Zoom;
            this.pictureBox1.TabIndex = 7;
            this.pictureBox1.TabStop = false;
            // 
            // LanChat
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.BackColor = System.Drawing.Color.Black;
            this.ClientSize = new System.Drawing.Size(632, 469);
            this.Controls.Add(this.pictureBox1);
            this.Controls.Add(this.buttonAdvertise);
            this.Controls.Add(this.buttonStop);
            this.Controls.Add(this.richTextBoxRecieveMsg);
            this.Controls.Add(this.richTextBoxSendMsg);
            this.Controls.Add(this.buttonSend);
            this.Controls.Add(this.comboBoxUserNames);
            this.Controls.Add(this.label1);
            this.ForeColor = System.Drawing.Color.White;
            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
            this.MaximizeBox = false;
            this.Name = "LanChat";
            this.ShowInTaskbar = false;
            this.Text = "Chat";
            this.Closing += new System.ComponentModel.CancelEventHandler(this.Form1_Closing);
            ((System.ComponentModel.ISupportInitialize) (this.pictureBox1)).EndInit();
            this.ResumeLayout(false);
            this.PerformLayout();
        }
 
        #endregion
    }
}
using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Net;
using System.Net.Sockets;
using System.Reflection;
using System.Security.Principal;
using System.Text;
using System.Threading;
using System.Windows.Forms;

namespace LanChat
{
    public class LanChat : Form
    {
        public Button buttonAdvertise;
        public Button buttonSend;
        public Button buttonStop;
        public ComboBox comboBoxUserNames;
        public IContainer components;
        public ContextMenu contextMenuNotify;
        private bool IsThreadRunning = false;
        public Label label1;
        public MenuItem menuItem3;
        public MenuItem menuItemAbout;
        public MenuItem menuItemExit;
        public MenuItem menuItemOpen;
        public NotifyIcon notifyIcon;
        public PictureBox pictureBox1;
        public RichTextBox richTextBoxRecieveMsg;
        public RichTextBox richTextBoxSendMsg;
        private ReaderWriterLock rwl = new ReaderWriterLock();
        private Thread thread;
        private ArrayList userList = new ArrayList();

        public LanChat()
        {
            InitializeComponent();
            thread = new Thread(new ThreadStart(MulticastListener));
            thread.Start();
            String message = "Hello$" + GetUserName();
            MulticastSend("224.168.100.2", 1000, message);
            notifyIcon.Icon = LoadIcon();
            Icon = LoadIcon();
        }

        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                if (components != null)
                {
                    components.Dispose();
                }
            }
            base.Dispose(disposing);
        }

        [STAThread]
        private static void Main()
        {
            LanChat f = new LanChat();
            Application.Run(f);
        }

        public void buttonSend_Click(object sender, EventArgs e)
        {
            if (richTextBoxSendMsg.Text == "")
                return;
            String message = "MSG:$" + GetUserName() + " : " + richTextBoxSendMsg.Text;
            string[] host = comboBoxUserNames.Text.Split('\\');
            if (host.Length > 1)
            {
                string hostName = Dns.GetHostByName(host[0]).AddressList[0].ToString();
                MulticastSend(hostName, 1000, message);
                richTextBoxSendMsg.Text = "";
            }
        }

        public void buttonAdvertise_Click(object sender, EventArgs e)
        {
            String message = "Hello$" + GetUserName();
            MulticastSend("224.168.100.2", 1000, message);
        }

        public void buttonStop_Click(object sender, EventArgs e)
        {
            String message = "Stop$" + GetUserName();
            MulticastSend("224.168.100.2", 1000, message);
        }

        public void Form1_Closing(object sender, CancelEventArgs e)
        {
            rwl.AcquireWriterLock(10);
            IsThreadRunning = false;
            rwl.ReleaseWriterLock();
            thread.Abort();
        }

        public void MulticastListener()
        {
            recv("224.168.100.2", "1000");
            Controls.Add(comboBoxUserNames);
        }

        public void MulticastSend(string mAddress, int port, string message)
        {
            try
            {
                IPAddress GroupAddress = IPAddress.Parse(mAddress);
                int GroupPort = port;
                UdpClient sender = new UdpClient();
                IPEndPoint groupEP = new IPEndPoint(GroupAddress, GroupPort);
                byte[] bytes = Encoding.ASCII.GetBytes(message);
                sender.Send(bytes, bytes.Length, groupEP);
                sender.Close();
            }
            catch (Exception e)
            {
                MessageBox.Show(e.ToString());
            }
        }

        private void recv(string mcastGroup, string port)
        {
            Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
            IPEndPoint ipep = new IPEndPoint(IPAddress.Any, int.Parse(port));
            s.Bind(ipep);
            IPAddress ip = IPAddress.Parse(mcastGroup);
            s.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.AddMembership,
                              new MulticastOption(ip, IPAddress.Any));
            IsThreadRunning = true;
            while (IsThreadRunning)
            {
                byte[] b = new byte[500];
                s.Receive(b);
                string str = Encoding.ASCII.GetString(b, 0, b.Length);
                str = str.Replace("\0", "");
                if (str.StartsWith("Hello"))
                {
                    string[] array = str.Split('$');
                    if (array.Length > 1)
                    {
                        if (!userList.Contains(array[1].ToString()))
                        {
                            userList.Add(array[1]);
                            UpdateComboBox();
                        }
                    }
                }
                else if (str.StartsWith("Stop"))
                {
                    string[] array = str.Split('$');
                    if (array.Length > 1)
                    {
                        if (userList.Contains(array[1].ToString()))
                        {
                            userList.Remove(array[1]);

                            if (comboBoxUserNames.InvokeRequired)
                            {
                                comboBoxUserNames.Invoke(new UpdateComboBoxHandler(UpdateComboBox));
                            }
                            else
                            {
                                UpdateComboBox();
                            }
                        }
                    }
                }
                else if (str.StartsWith("MSG:"))
                {
                    int start = -1;
                    int length = -1;
                    if (richTextBoxRecieveMsg.InvokeRequired)
                    {
                        if (richTextBoxRecieveMsg.InvokeRequired)
                            richTextBoxSendMsg.Invoke(new SetStartHandler(UpdateControl), new object[] {start, str, length});
                    }
                    else
                    {
                        UpdateControl(ref start, ref str, ref length);
                    }
                }
            }
        }

        private delegate void UpdateComboBoxHandler();
        private delegate void SetStartHandler(ref int start, ref string str, ref int length);
        private void UpdateControl(ref int start, ref string str, ref int length)
        {
            str = str.Replace("MSG:$", "");
            start = richTextBoxSendMsg.TextLength;
            length = str.IndexOf(':');
            richTextBoxRecieveMsg.AppendText(str + "\n");
            if (start >= 0 && start < richTextBoxRecieveMsg.TextLength && length > 0 &&
                length + start < richTextBoxRecieveMsg.TextLength)
            {
                richTextBoxRecieveMsg.Select(start, length);
                richTextBoxRecieveMsg.SelectionColor = Color.Blue;
                richTextBoxRecieveMsg.SelectionLength = 0;
            }
        }

        public void UpdateComboBox()
        {
            comboBoxUserNames.Items.Clear();
            comboBoxUserNames.Items.AddRange(userList.ToArray());
        }

        private string GetUserName()
        {
            string str;
            str = WindowsIdentity.GetCurrent().Name.ToString();
            return str;
        }

        private Icon LoadIcon()
        {
            Assembly assembly = typeof (LanChat).Assembly;
            string Name = "LanChat.LanChat.ico";
            return null;
        }

        public void notifyIcon_DoubleClick(object sender, EventArgs e)
        {
            if (WindowState == FormWindowState.Minimized)
                WindowState = FormWindowState.Normal;
            Activate();
        }

        public void menuItemOpen_Click(object sender, EventArgs e)
        {
            Activate();
        }

        public void menuItemAbout_Click(object sender, EventArgs e)
        {
//            About about = new About();
//            about.Location = MousePosition;
//            about.Show();
        }

        public void menuItemExit_Click(object sender, EventArgs e)
        {
            Close();
        }

        #region Windows Form Designer generated code

        private void InitializeComponent()
        {
            this.components = new System.ComponentModel.Container();
            this.richTextBoxRecieveMsg = new System.Windows.Forms.RichTextBox();
            this.label1 = new System.Windows.Forms.Label();
            this.comboBoxUserNames = new System.Windows.Forms.ComboBox();
            this.buttonSend = new System.Windows.Forms.Button();
            this.richTextBoxSendMsg = new System.Windows.Forms.RichTextBox();
            this.buttonStop = new System.Windows.Forms.Button();
            this.buttonAdvertise = new System.Windows.Forms.Button();
            this.contextMenuNotify = new System.Windows.Forms.ContextMenu();
            this.menuItemOpen = new System.Windows.Forms.MenuItem();
            this.menuItemAbout = new System.Windows.Forms.MenuItem();
            this.menuItem3 = new System.Windows.Forms.MenuItem();
            this.menuItemExit = new System.Windows.Forms.MenuItem();
            this.notifyIcon = new System.Windows.Forms.NotifyIcon(this.components);
            this.pictureBox1 = new System.Windows.Forms.PictureBox();
            ((System.ComponentModel.ISupportInitialize) (this.pictureBox1)).BeginInit();
            this.SuspendLayout();
            // 
            // richTextBoxRecieveMsg
            // 
            this.richTextBoxRecieveMsg.BackColor = System.Drawing.Color.WhiteSmoke;
            this.richTextBoxRecieveMsg.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
            this.richTextBoxRecieveMsg.Font =
                new System.Drawing.Font("Courier New", 9F, System.Drawing.FontStyle.Regular,
                                        System.Drawing.GraphicsUnit.Point, ((byte) (0)));
            this.richTextBoxRecieveMsg.Location = new System.Drawing.Point(7, 176);
            this.richTextBoxRecieveMsg.Name = "richTextBoxRecieveMsg";
            this.richTextBoxRecieveMsg.ReadOnly = true;
            this.richTextBoxRecieveMsg.ShowSelectionMargin = true;
            this.richTextBoxRecieveMsg.Size = new System.Drawing.Size(535, 218);
            this.richTextBoxRecieveMsg.TabIndex = 0;
            this.richTextBoxRecieveMsg.Text = "";
            // 
            // label1
            // 
            this.label1.AutoSize = true;
            this.label1.BackColor = System.Drawing.Color.Black;
            this.label1.Font =
                new System.Drawing.Font("Courier New", 9.75F, System.Drawing.FontStyle.Regular,
                                        System.Drawing.GraphicsUnit.Point, ((byte) (0)));
            this.label1.Location = new System.Drawing.Point(219, 27);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(80, 16);
            this.label1.TabIndex = 1;
            this.label1.Text = "User Name";
            // 
            // comboBoxUserNames
            // 
            this.comboBoxUserNames.BackColor = System.Drawing.Color.WhiteSmoke;
            this.comboBoxUserNames.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
            this.comboBoxUserNames.Location = new System.Drawing.Point(305, 25);
            this.comboBoxUserNames.Name = "comboBoxUserNames";
            this.comboBoxUserNames.Size = new System.Drawing.Size(152, 21);
            this.comboBoxUserNames.TabIndex = 2;
            // 
            // buttonSend
            // 
            this.buttonSend.BackColor = System.Drawing.Color.Black;
            this.buttonSend.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
            this.buttonSend.Font =
                new System.Drawing.Font("Courier New", 9.75F, System.Drawing.FontStyle.Bold,
                                        System.Drawing.GraphicsUnit.Point, ((byte) (0)));
            this.buttonSend.ForeColor = System.Drawing.Color.White;
            this.buttonSend.Location = new System.Drawing.Point(548, 409);
            this.buttonSend.Name = "buttonSend";
            this.buttonSend.Size = new System.Drawing.Size(72, 48);
            this.buttonSend.TabIndex = 3;
            this.buttonSend.Text = "Send";
            this.buttonSend.UseVisualStyleBackColor = false;
            this.buttonSend.Click += new System.EventHandler(this.buttonSend_Click);
            // 
            // richTextBoxSendMsg
            // 
            this.richTextBoxSendMsg.BackColor = System.Drawing.Color.WhiteSmoke;
            this.richTextBoxSendMsg.BorderStyle = System.Windows.Forms.BorderStyle.None;
            this.richTextBoxSendMsg.Font =
                new System.Drawing.Font("Microsoft Sans Serif", 9F, System.Drawing.FontStyle.Regular,
                                        System.Drawing.GraphicsUnit.Point, ((byte) (0)));
            this.richTextBoxSendMsg.Location = new System.Drawing.Point(7, 409);
            this.richTextBoxSendMsg.MaxLength = 500;
            this.richTextBoxSendMsg.Name = "richTextBoxSendMsg";
            this.richTextBoxSendMsg.ShowSelectionMargin = true;
            this.richTextBoxSendMsg.Size = new System.Drawing.Size(535, 48);
            this.richTextBoxSendMsg.TabIndex = 4;
            this.richTextBoxSendMsg.Text = "";
            // 
            // buttonStop
            // 
            this.buttonStop.BackColor = System.Drawing.Color.Black;
            this.buttonStop.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
            this.buttonStop.Font =
                new System.Drawing.Font("Courier New", 9.75F, System.Drawing.FontStyle.Regular,
                                        System.Drawing.GraphicsUnit.Point, ((byte) (0)));
            this.buttonStop.Location = new System.Drawing.Point(355, 73);
            this.buttonStop.Name = "buttonStop";
            this.buttonStop.Size = new System.Drawing.Size(100, 24);
            this.buttonStop.TabIndex = 5;
            this.buttonStop.Text = "Stop";
            this.buttonStop.UseVisualStyleBackColor = false;
            this.buttonStop.Click += new System.EventHandler(this.buttonStop_Click);
            // 
            // buttonAdvertise
            // 
            this.buttonAdvertise.BackColor = System.Drawing.Color.Black;
            this.buttonAdvertise.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
            this.buttonAdvertise.Font =
                new System.Drawing.Font("Courier New", 9.75F, System.Drawing.FontStyle.Regular,
                                        System.Drawing.GraphicsUnit.Point, ((byte) (0)));
            this.buttonAdvertise.Location = new System.Drawing.Point(249, 73);
            this.buttonAdvertise.Name = "buttonAdvertise";
            this.buttonAdvertise.Size = new System.Drawing.Size(100, 24);
            this.buttonAdvertise.TabIndex = 6;
            this.buttonAdvertise.Text = "Advertise";
            this.buttonAdvertise.UseVisualStyleBackColor = false;
            this.buttonAdvertise.Click += new System.EventHandler(this.buttonAdvertise_Click);
            // 
            // contextMenuNotify
            // 
            this.contextMenuNotify.MenuItems.AddRange(new System.Windows.Forms.MenuItem[]
                                                          {
                                                              this.menuItemOpen,
                                                              this.menuItemAbout,
                                                              this.menuItem3,
                                                              this.menuItemExit
                                                          });
            // 
            // menuItemOpen
            // 
            this.menuItemOpen.Index = 0;
            this.menuItemOpen.Text = "Open";
            this.menuItemOpen.Click += new System.EventHandler(this.menuItemOpen_Click);
            // 
            // menuItemAbout
            // 
            this.menuItemAbout.Index = 1;
            this.menuItemAbout.Text = "About LanChat";
            this.menuItemAbout.Click += new System.EventHandler(this.menuItemAbout_Click);
            // 
            // menuItem3
            // 
            this.menuItem3.Index = 2;
            this.menuItem3.Text = "-";
            // 
            // menuItemExit
            // 
            this.menuItemExit.Index = 3;
            this.menuItemExit.Text = "Exit";
            this.menuItemExit.Click += new System.EventHandler(this.menuItemExit_Click);
            // 
            // notifyIcon
            // 
            this.notifyIcon.ContextMenu = this.contextMenuNotify;
            this.notifyIcon.Text = "notifyIcon";
            this.notifyIcon.Visible = true;
            this.notifyIcon.DoubleClick += new System.EventHandler(this.notifyIcon_DoubleClick);
            // 
            // pictureBox1
            // 
//            this.pictureBox1.Image = global::LanChat.Properties.Resources.forweb;
            this.pictureBox1.Location = new System.Drawing.Point(12, 12);
            this.pictureBox1.Name = "pictureBox1";
            this.pictureBox1.Size = new System.Drawing.Size(201, 151);
            this.pictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.Zoom;
            this.pictureBox1.TabIndex = 7;
            this.pictureBox1.TabStop = false;
            // 
            // LanChat
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.BackColor = System.Drawing.Color.Black;
            this.ClientSize = new System.Drawing.Size(632, 469);
            this.Controls.Add(this.pictureBox1);
            this.Controls.Add(this.buttonAdvertise);
            this.Controls.Add(this.buttonStop);
            this.Controls.Add(this.richTextBoxRecieveMsg);
            this.Controls.Add(this.richTextBoxSendMsg);
            this.Controls.Add(this.buttonSend);
            this.Controls.Add(this.comboBoxUserNames);
            this.Controls.Add(this.label1);
            this.ForeColor = System.Drawing.Color.White;
            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
            this.MaximizeBox = false;
            this.Name = "LanChat";
            this.ShowInTaskbar = false;
            this.Text = "Chat";
            this.Closing += new System.ComponentModel.CancelEventHandler(this.Form1_Closing);
            ((System.ComponentModel.ISupportInitialize) (this.pictureBox1)).EndInit();
            this.ResumeLayout(false);
            this.PerformLayout();
        }

        #endregion
    }
}

•

Join Date: Apr 2004

Posts: 127

Reputation: johnroach1985 is an unknown quantity at this point

Solved Threads: 0

johnroach1985 johnroach1985 is offline

Offline

Junior Poster

Re: Thread's colliding?

Nov 29th, 2007

Hi the program still gives a

Help with Code Tags

C# Syntax (Toggle Plain Text)

Cross-thread operation not valid: Control 'comboBoxUserNames' accessed from a thread other than the thread it was created on.

Error after you click the advertise button and than the combobox...

The error is given at

 Help with Code Tags 
 C# Syntax (Toggle Plain Text) 
 public void UpdateComboBox()
 
      {
 
      comboBoxUserNames.Items.Clear();
 
      comboBoxUserNames.Items.AddRange(userList.ToArray());
 
      }
 public void UpdateComboBox()

      {

      comboBoxUserNames.Items.Clear();

      comboBoxUserNames.Items.AddRange(userList.ToArray());
 
      }

•

Join Date: Dec 2005

Posts: 45

Reputation: _r0ckbaer is an unknown quantity at this point

Solved Threads: 7

_r0ckbaer

Offline

Light Poster

Re: Thread's colliding?

Nov 29th, 2007

Try to correct that one by yourself, the answer is right there in the code, have a look at how i handle the other case (it's exactly the same), we're not here to chew you every piece in advance...