NLog provides consistent logging capabilities across various .NET application types including console apps, WinForms, and WPF. This demonstrasion uses a .NET 5 console application.

1. Adding NLog Dependency

There are two approaches to include NLog in your project:

1. Install via NuGet package manager
2. Directly reference the NLog.dll assembly

2. Configuration Setup

Create an NLog.config file in your project with the folllowing properties:

• Set 'Copy to Output Directory' to 'Copy if newer'
• Configure logging targets and rules as shown:

<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      autoReload="true"
      throwExceptions="false">

  <targets>
    <target name="logfile" 
            xsi:type="File" 
            fileName="${basedir}/logs/app.log"
            archiveAboveSize="1048576"
            maxArchiveFiles="5"
            layout="${longdate} | ${level} | ${message}" />
  </targets>

  <rules>
    <logger name="*" minlevel="Debug" writeTo="logfile" />
  </rules>
</nlog>

3. Logger Implementation

Create a wrapper class for simplified logging operations:

public static class AppLogger
{
    private static Logger _logger = LogManager.GetCurrentClassLogger();

    public static void Initialize(string configPath)
    {
        if (!File.Exists(configPath))
            throw new FileNotFoundException("NLog configuration missing");

        LogManager.LoadConfiguration(configPath);
    }

    public static void LogDebug(string message) => _logger.Debug(message);
    public static void LogInformation(string message) => _logger.Info(message);
    public static void LogWarning(string message) => _logger.Warn(message);
    public static void LogError(string message) => _logger.Error(message);
    public static void LogCritical(string message) => _logger.Fatal(message);
}

4. Usage Example

static void Main()
{
    var configPath = Path.Combine(
        Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location),
        "NLog.config");

    AppLogger.Initialize(configPath);

    AppLogger.LogDebug("Debug message");
    AppLogger.LogInformation("Information message");
    AppLogger.LogWarning("Warning message");
    AppLogger.LogError("Error message");

    LogManager.Shutdown();
}