Can you configure log4net in code instead of using a config file?

Question

I understand why log4net uses app.config files for setting up logging - so you can easily change how information is logged without needing to recompile your cod

Answer 1

The accepted answer works after I found two caveats:

• It was not working for me at first, but after using a full absolue path for the roller.File property, it started work.
• I had to use this in F# (in a fsx script), so had some issues when converting it from C#. If you're interested in the end result (including a way to download log4net nuget package), see below:

nuget_log4net.fsx:

#!/usr/bin/env fsharpi

open System
open System.IO
open System.Net

#r "System.IO.Compression.FileSystem"
open System.IO.Compression

type DummyTypeForLog4Net () =
    do ()

module NetTools =

    let DownloadNuget (packageId: string, packageVersion: string) =
    use webClient = new WebClient()
    let fileName = sprintf "%s.%s.nupkg" packageId packageVersion

    let pathToUncompressTo = Path.Combine("packages", packageId)
    if (Directory.Exists(pathToUncompressTo)) then
        Directory.Delete(pathToUncompressTo, true)
    Directory.CreateDirectory(pathToUncompressTo) |> ignore
    let fileToDownload = Path.Combine(pathToUncompressTo, fileName)

    let nugetDownloadUri = Uri (sprintf "https://www.nuget.org/api/v2/package/%s/%s" packageId packageVersion)
    webClient.DownloadFile (nugetDownloadUri, fileToDownload)

    ZipFile.ExtractToDirectory(fileToDownload, pathToUncompressTo)

let packageId = "log4net"
let packageVersion = "2.0.5"
NetTools.DownloadNuget(packageId, packageVersion)

let currentDirectory = Directory.GetCurrentDirectory()

// https://stackoverflow.com/a/19538654/6503091
#r "packages/log4net/lib/net45-full/log4net"

open log4net
open log4net.Repository.Hierarchy
open log4net.Core
open log4net.Appender
open log4net.Layout
open log4net.Config

let patternLayout = PatternLayout()
patternLayout.ConversionPattern <- "%date [%thread] %-5level %logger - %message%newline";
patternLayout.ActivateOptions()

let roller = RollingFileAppender()
roller.AppendToFile <- true
roller.File <- Path.Combine(currentDirectory, "someLog.txt")
roller.Layout <- patternLayout
roller.MaxSizeRollBackups <- 5
roller.MaximumFileSize <- "1GB"
roller.RollingStyle <- RollingFileAppender.RollingMode.Size
roller.StaticLogFileName <- true
roller.ActivateOptions ()

let hierarchy = box (LogManager.GetRepository()) :?> Hierarchy
hierarchy.Root.AddAppender (roller)

hierarchy.Root.Level <- Level.Info
hierarchy.Configured <- true
BasicConfigurator.Configure(hierarchy)

let aType = typedefof
let logger = LogManager.GetLogger(aType)

logger.Error(new Exception("exception test"))