How to Trace all local variables when an exception occurs

private static void TraceMethodArguments(MethodExecutionEventArgs eventArgs)
    {
        object[] parameters = eventArgs.GetReadOnlyArgumentArray();

        if (parameters != null)
        {
            string paramValue = null;
            foreach (object p in parameters)
            {
                Type _type = p.GetType();
                if (_type == typeof(string) || _type == typeof(int) || _type == typeof(double) || _type == typeof(decimal))
                {
                    paramValue = (string)p;
                }
                else if (_type == typeof(XmlDocument))
                {
                    paramValue = ((XmlDocument)p).OuterXml;
                }
                else
                { //try to serialize
                    try
                    {
                        XmlSerializer _serializer = new XmlSerializer(p.GetType());
                        StringWriter _strWriter = new StringWriter();

                        _serializer.Serialize(_strWriter, p);
                        paramValue = _strWriter.ToString();
                    }
                    catch
                    {
                        paramValue = "Unable to Serialize Parameter";
                    }
                }
                Trace.TraceInformation("[" + Process.GetCurrentProcess().Id + "-" + Thread.CurrentThread.ManagedThreadId.ToString() + "]" + " Parameter: " + paramValue);
            }
        }
    }