[C#] Exception Tracing Sample Code

string exceptionLogFile = Path.Combine(Path.GetDirectoryName(Application.ExecutablePath), @"Exception.txt");

private void checkBoxTopMost_CheckedChanged(object sender, EventArgs e)
{
    try
    {
        this.TopMost = this.checkBoxTopMost.Checked;
    }
    catch (Exception ex)
    {
        StackFrame fr = new StackFrame(true);
        StackTrace st = new StackTrace(fr);
        MethodBase mb = fr.GetMethod();
        recordExceptionLog(ex, mb.Name, fr.GetFileLineNumber(), st.ToString());
    }
}

/// <summary>
/// Record Exception Message to Log File
/// </summary>
private void recordExceptionLog(Exception ex, string methodName, int lineNumber, string stackTraceString)
{
    string exMessage = String.Format("{0}{1}\t[{2}:{3}] {4}",
        DateTime.Now.ToString(), stackTraceString, methodName, lineNumber, ex.Message);

    using (StreamWriter sw = new StreamWriter(exceptionLogFile, true))
    {
        sw.WriteLine(exMessage);
    }
}