public void Log(ErrorLevel level, Exception ex, string message, params object[] arg) { if (level == ErrorLevel.Debug) { return; } var tmp = new StringBuilder(); tmp.Append(level.LevelName()); if (ex != null) { tmp.Append(" "); tmp.Append(ex.Message); } tmp.Append(" "); tmp.AppendFormat(message, arg); this.messages.Add(tmp.ToString()); }