Catching and logging error in Custom code(ULS logging)

using System;

using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.SharePoint.Administration;

 namespace CommonCode

{
    public class ULSLogging : SPDiagnosticsServiceBase

    {

        public static string DiagnosticAreaName = "CodeChallege LOG";

        private static ULSLogging _Current;

        public static ULSLogging Current

        {

       

     get

            {

                if (_Current == null)

                {

                    _Current = new ULSLogging();

                }

                return _Current;

            }

        }

        private ULSLogging()

            : base("CodeChallege Logging Service", SPFarm.Local)

        {

        }

        protected override IEnumerable<SPDiagnosticsArea> ProvideAreas()

        {

            List<SPDiagnosticsArea> areas = new List<SPDiagnosticsArea>

        {

            new SPDiagnosticsArea(DiagnosticAreaName, new List<SPDiagnosticsCategory>

            {

                new SPDiagnosticsCategory("CodeChallege", TraceSeverity.Unexpected, EventSeverity.Error)

            })

        };

            return areas;

        }

        public static void LogError(string categoryName, string errorMessage)

        {

            SPDiagnosticsCategory category = ULSLogging.Current.Areas[DiagnosticAreaName].Categories[categoryName];

            ULSLogging.Current.WriteTrace(0, category, TraceSeverity.Unexpected, errorMessage);

        }

    }

}

in Catch block call above methode as below:-

ULSLogging.LogError("CodeChallege", ex.Message);