SplatToSerilogLogger.cs

using System;

public class SplatToSerilogLogger : Splat.ILogger
{
    public Serilog.ILogger Serilog { get; set; } = global::Serilog.Log.Logger;

    public void Write(string message, Splat.LogLevel logLevel)
    {
        if ((int)logLevel >= (int)Level)
        {
            switch (logLevel)
            {
                case Splat.LogLevel.Debug:
                    Serilog.Debug(message);
                    break;

                case Splat.LogLevel.Info:
                    Serilog.Information(message);
                    break;

                case Splat.LogLevel.Warn:
                    Serilog.Warning(message);
                    break;

                case Splat.LogLevel.Error:
                    Serilog.Error(message);
                    break;

                case Splat.LogLevel.Fatal:
                    Serilog.Fatal(message);
                    break;

                default:
                    throw new ArgumentOutOfRangeException(nameof(logLevel), logLevel, null);
            }
        }
    }

    public Splat.LogLevel Level { get; set; }
}