Simple Logger using Caller Info Attributes

Since .NET 4.5 There are 3 caller info attributes that are filled in at compile time by the compiler CallerMemberName, CallerFilePath, and CallerLineNumber These strings are inserted at compile time so they are much faster than using reflection.

Here is an example of how to use it to make the simplest logger (only 1 method + 1 property):

using System.Runtime.CompilerServices;

public enum LoggingLevelEnum
{
    Debug = 1,
    Info = 2,
    Warning = 3,
    Error = 4,
    Fatal = 5
}

public interface ISimpleLogger
{
    LoggingLevelEnum LoggingLevel { get; set; }

    void Log(
        Func<string> message,
        LoggingLevelEnum level = LoggingLevelEnum.Debug,
        [CallerMemberName] string member = "",
        [CallerFilePath] string file = "",
        [CallerLineNumber] int line = -1)
}

public class SimpleLogger : ISimpleLogger
{
    public LoggingLevelEnum LoggingLevel { get; set; } = 
        LoggingLevelEnum.Debug;

    public void Log(
        Func<string> message,
        LoggingLevelEnum level = LoggingLevelEnum.Debug,
        [CallerMemberName] string member = "",
        [CallerFilePath] string file = "",
        [CallerLineNumber] int line = -1)
    {
        if (level >= LoggingLevel)
        {
            Trace.WriteLine($"{level.ToString().ToUpper()} Member: {member}, File: {file}, Line: {line} - {message()}");
        }
    }
}

and invoking it:

ISimpleLogger logger = new SimpleLogger();
...
catch(Exception ex)
{
  // The attributed parameters are inserted by the compiler at compile time
  logger.Log(() => { return " Exception caught " + ex.ToString(); }, LogLevelEnum.Error); 
}

Note: Why log using a function returning a string? So that if you have a complex expression for creating the message, it only gets evaluated if the logging level is sufficient. If there is a lot of logging and the logging level is high, it saves a lot of unecessary string concatenation occurring.