System.Diagnostics.StackTrace.ToString C# (CSharp) Method

        public override string ToString() { throw null; }
    }

        public static void LogEvent(string details)
        {
            StackTrace st = new StackTrace();
            // Putting into the string with only current program stack trace
            string stack = st.ToString().Substring(0, st.ToString().IndexOf("   at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)") - 2);
            stack = stack.Replace("at", "");
            stack = stack.Replace(" ", "");
            stack = stack.Replace("\r\n", "|");
            // Reversing
            string[] all = stack.Split('|');
            Array.Reverse(all);
            stack = "";
            bool first = true;
            foreach (var s in all)
            {
                if (first == false)
                {
                    stack += "->";
                }
                else
                {
                    first = false;
                }
                stack += s;
            }

            string message = "";
            string currentDate = DateTime.Now.ToString("yyyy-MM-dd", CultureInfo.GetCultureInfo("en-US"));
            string currentTime = DateTime.Now.ToString("HH:mm:ss");

            message = currentDate + " " + currentTime + " [" + stack + "] " + details;

            StreamWriter writer = null;

            try
            {
                writer = OpenFile(DateTime.Now.ToString("yyyy-MM-dd", CultureInfo.GetCultureInfo("en-US")));
            }
            catch (Exception e)
            {
                writer = OpenFile(DateTime.Now.ToString("yyyy-MM-dd", CultureInfo.GetCultureInfo("en-US")) + "ERROR");
                message = e.Message;
            }

            try
            {
                writer.WriteLine(message);
            }
            catch (Exception e)
            {
                writer.Close();

                writer = new StreamWriter("ERROR.log", true);
                writer.WriteLine(message);
            }

            CloseFile(writer);
        }