README.md

PrismNetCoreLoggingApp

This Sample demonstrates the usage of Microsoft.Extensions.Logging in a Xamarin.Forms App (with Prism and DryIoc Container) in the same way as in a ASP.NET Core Web-Application.

Usage

You can use any constructor (e.g. ViewModel, Service, ...) to get the logger injected:

public MyService(ILogger<MyService> logger)
{
  this.logger = logger;
}

Setup

Installing Microsoft.Extensions.Logging

Due to a bug (see here it is not just enought to install the Microsoft.Extensions.Logging nuget package. You had to set the package System.Runtime.CompilerServices.Unsafe to a special version and disable a nuget warning in the main project .csproj like that:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>netstandard2.0</TargetFramework>
    <NoWarn>$(NoWarn);NU1605</NoWarn>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="2.0.0" />
    <PackageReference Include="Xamarin.Forms" Version="2.5.0.280555" />
    <PackageReference Include="Prism.DryIoc.Forms" Version="7.0.0.396" />
    <!-- Due to a bug in version 4.4.0 use 4.3.0-->
    <PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="4.3.0" />
  </ItemGroup>

</Project>

After that you are able to use the Microsoft.Extensions.Logging Package e.g. with the Microsoft.Extensions.Logging.Debug package (for further information about the usage look here)

Register Logger in DryIoc Container

At next you had to create the logger factory and register the logger with the container. This shows the registration in the App.xaml.cs:

protected override void RegisterTypes(IContainerRegistry containerRegistry)
{
  containerRegistry.RegisterForNavigation<NavigationPage>();
  containerRegistry.RegisterForNavigation<MainPage>();

  // register services
  containerRegistry.RegisterSingleton<IMyService, MyService>();

  // create logger factory
  ILoggerFactory loggerFactory = new LoggerFactory().AddDebug();

  // get the container
  var container = containerRegistry.GetContainer();

  // register factory
  container.UseInstance(loggerFactory);

  // get the factory method
  var loggerFactoryMethod = typeof(LoggerFactoryExtensions).GetMethod("CreateLogger", new Type[] { typeof(ILoggerFactory) });

  // register logger with factory method
  container.Register(typeof(ILogger<>), made: Made.Of(req => loggerFactoryMethod.MakeGenericMethod(req.Parent.ImplementationType)));
}

Hint

This is running on Android and WUP, but I couldn't test iOS. If you are able to run this sample successfully on iOS please let me know so that I can update this readme.

Special Thanks to dadhi for getting this running at https://stackoverflow.com/questions/48911710/register-iloggerfactory-in-dryioc-container/