C#

<br />
	public class LogClass <br />
	{<br />
		private TextBoxBase outputWin = null;<br />
<br />
		public LogClass(TextBoxBase win)<br />
		{<br />
			outputWin = win;<br />
		}<br />
<br />
		public void ShowMessage(string message)<br />
		{<br />
			string s = System.DateTime.Now.ToString() + ": " + message + "\r\n";<br />
			lock ( this ) <br />
			{<br />
				// show the log message to output window<br />
				if ( outputWin != null ) <br />
				{<br />
					if ( s.Length + outputWin.TextLength > outputWin.MaxLength ) <br />
					{<br />
						outputWin.Text = "";<br />
					}<br />
					outputWin.Text += s;<br />
				}<br />
                          }<br />
}<br />
}<br />
<br />
<br />
public MyClass<br />
{<br />
		private System.Windows.Forms.TextBox logBox;<br />
<br />
private void DoSomething()<br />
{<br />
	log.ShowMessage("thread running" );<br />
}<br />
<br />
		private void button3_Click(object sender, System.EventArgs e)<br />
		{<br />
				log.ShowMessage( "start test" );<br />
				Thread[] t = new Thread[10];<br />
				int i = 0;<br />
				for ( i = 0; i < 10; i ++ )<br />
				{<br />
					t[i] = new Thread(new ThreadStart(this.DoSomething));<br />
					t[i].Start();<br />
					Thread.Sleep(100);<br />
				}<br />
<br />
				log.ShowMessage( "end test" );<br />
			}<br />
		}<br />
<br />
		public MyClass()<br />
		{<br />
			log = new LogClass( logBox);<br />
                }<br />
<br />
}