.net logger without any dependencies

Logger.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;

namespace Portal.Common
{
    public class Logger
    {
        private static Logger _defaultLogger = null;
        public Logger(string fileName)
        {
            try
            {
                Trace.Listeners.Clear();
                Trace.Listeners.Add(new TextWriterTraceListener(fileName));
                Trace.AutoFlush = true;
            }
            catch (Exception)
            {
                throw;
            }

        }

        public Logger()
            : this("app.log")
        {
            
        }

        public static Logger Default
        {
            get
            {
                if (_defaultLogger == null)
                {
                    _defaultLogger = new Logger();
                }
                return _defaultLogger;
            }
        }


        public void Info(string msg)
        {
            this.Info("{0}", msg);
        }
        public void Info(string format, params string[] msg)
        {
            Trace.WriteLine(string.Format("{0} [{1}] {2}",
                DateTime.Now, "INFO",
                string.Format(format, msg)));
        }
        public void InfoIf(bool condition, string format, params string[] msg)
        {
            Trace.WriteLineIf(condition, string.Format("{0} [{1}] {2}",
                DateTime.Now, "INFO",
                string.Format(format, msg)));
        }

        public void Warn(string format, params string[] msg)
        {
            Trace.WriteLine(string.Format("{0} [{1}] {2}",
                DateTime.Now, "WARN",
                string.Format(format, msg)));
        }
        public void WarnIf(bool condition, string format, params string[] msg)
        {
            Trace.WriteLineIf(condition, string.Format("{0} [{1}] {2}",
                DateTime.Now, "WARN",
                string.Format(format, msg)));
        }

        public void Error(string format, params string[] msg)
        {
            Trace.WriteLine(string.Format("{0} [{1}] {2}",
                DateTime.Now, "ERRO",
                string.Format(format, msg)));
        }
        public void ErrorIf(bool condition, string format, params string[] msg)
        {
            Trace.WriteLineIf(condition, string.Format("{0} [{1}] {2}",
                DateTime.Now, "ERRO",
                string.Format(format, msg)));
        }

    }
}