ToLogString

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;

public static class Extensions
{

    #region Exception.ToLogString
    /// <summary>
    /// <para>Creates a log-string from the Exception.</para>
    /// <para>The result includes the stacktrace, innerexception et cetera, separated by <seealso cref="Environment.NewLine"/>.</para>
    /// </summary>
    /// <param name="ex">The exception to create the string from.</param>
    /// <param name="additionalMessage">Additional message to place at the top of the string, maybe be empty or null.</param>
    /// <returns></returns>
    public static string ToLogString(this Exception ex, string additionalMessage)
    {
        StringBuilder msg = new StringBuilder();

        if (!string.IsNullOrEmpty(additionalMessage))
        {
            msg.Append(additionalMessage);
            msg.Append(Environment.NewLine);
        }

        if (ex != null)
        {
            try
            {
                Exception orgEx = ex;

                msg.Append("Exception:");
                msg.Append(Environment.NewLine);
                while (orgEx != null)
                {
                    msg.Append(orgEx.Message);
                    msg.Append(Environment.NewLine);
                    orgEx = orgEx.InnerException;
                }

                if (ex.Data != null)
                {
                    foreach (object i in ex.Data)
                    {
                        msg.Append("Data :");
                        msg.Append(i.ToString());
                        msg.Append(Environment.NewLine);
                    }
                }

                if (ex.StackTrace != null)
                {
                    msg.Append("StackTrace:");
                    msg.Append(Environment.NewLine);
                    msg.Append(ex.StackTrace.ToString());
                    msg.Append(Environment.NewLine);
                }

                if (ex.Source != null)
                {
                    msg.Append("Source:");
                    msg.Append(Environment.NewLine);
                    msg.Append(ex.Source);
                    msg.Append(Environment.NewLine);
                }

                if (ex.TargetSite != null)
                {
                    msg.Append("TargetSite:");
                    msg.Append(Environment.NewLine);
                    msg.Append(ex.TargetSite.ToString());
                    msg.Append(Environment.NewLine);
                }

                Exception baseException = ex.GetBaseException();
                if (baseException != null)
                {
                    msg.Append("BaseException:");
                    msg.Append(Environment.NewLine);
                    msg.Append(ex.GetBaseException());
                }
            }
            finally
            {
            }
        }
        return msg.ToString();
    }
    #endregion Exception.ToLogString
}

Exception ex = new Exception(“This is an error”);
string log = ex.ToLogString(“A fatal error occurred!”);