public void Log(LogClass lClass, string message) { var log = string.Format("[{3}] {0} ==> {1}{2}", DateTime.Now.ToString("HH:mm:ss.fff"), message.Trim(), Environment.NewLine, lClass.ToString().ToUpper()); using (FileStream fileStream = File.Open(LogFile, FileMode.OpenOrCreate, FileAccess.ReadWrite)) { StreamWriter sw = new StreamWriter(fileStream); long endPoint = fileStream.Length; // Set the stream position to the end of the file. fileStream.Seek(endPoint, SeekOrigin.Begin); sw.Write(log); sw.Flush(); } }