Windows forms: to associate a trace listner to the default one and redirect it to a textBox using System.Diagnostics; public MainGUIForm() // The form contructor .... { InitializeComponent(); TraceListener debugListener = new MyTraceListener(txtConsole); // <<=== this redirects to the textbox! //Debug.Listeners.Add(debugListener); Trace.Listeners.Add(debugListener); .... public class MyTraceListener : TraceListener { private TextBoxBase output; public MyTraceListener(TextBoxBase output) { this.Name = "Trace"; this.output = output; } public override void Write(string message) { Action append = delegate() { //output.AppendText(string.Format("[{0}] ", DateTime.Now.ToString())); output.AppendText(message); }; if (output.InvokeRequired) output.BeginInvoke(append); else append(); } public override void WriteLine(string message) { Write(message + Environment.NewLine); } }