basic implementation of the C# ILogger interface using the Windows.Foundation.Diagnostics APIs

WinRTLoggerProvider.cs

internal class WinRTLoggerProvider : ILoggerProvider
{
    internal class WinRTLogger : ILogger, IDisposable
    {
        private readonly LoggingChannel channel;
        private readonly FileLoggingSession session;

        public WinRTLogger(string categoryName, FileLoggingSession session)
        {
            this.channel = new LoggingChannel(categoryName, new LoggingChannelOptions());
            this.session = session;
            session.AddLoggingChannel(channel);
        }

        public IDisposable BeginScope<TState>(TState state) where TState : notnull
        {
            return null;
        }

        public bool IsEnabled(LogLevel logLevel)
        {
            return true;
        }

        public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter)
        {
            var fields = new LoggingFields();
            fields.AddString("Message", formatter(state, exception));
            this.channel.LogEvent(eventId.ToString(), fields, MapLevel(logLevel));
        }

        private static LoggingLevel MapLevel(LogLevel level) => level switch
        {
            LogLevel.Trace or LogLevel.Debug => LoggingLevel.Verbose,
            LogLevel.Information => LoggingLevel.Information,
            LogLevel.Warning => LoggingLevel.Warning,
            LogLevel.Error => LoggingLevel.Error,
            LogLevel.Critical => LoggingLevel.Critical,
            _ => LoggingLevel.Verbose
        };

        public void Dispose()
        {
            this.session.RemoveLoggingChannel(this.channel);
        }
    }

    private FileLoggingSession session;
    public WinRTLoggerProvider()
    {
        this.session = new FileLoggingSession("Unicord-" + Guid.NewGuid().ToString());
    }

    public ILogger CreateLogger(string categoryName)
    {
        return new WinRTLogger(categoryName, session);
    }

    public async Task SaveAsync()
    {
        var oldSession = session;
        this.session = new FileLoggingSession("Unicord-" + Guid.NewGuid().ToString());

        await oldSession.CloseAndSaveToFileAsync();
    }

    public void Dispose()
    {
        this.session.Dispose();
    }
}