将 AddNLog 从 .NET Core 2.2 迁移到 3.0

Question

In the Startup class of my project I have the following Configure method:

private void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
    ...
    loggerFactory.AddNLog();
    ...
}

This worked OK in .NET Core 2.2, but after upgrading to 3.0, I get the warning Method 'NLog.Extensions.Logging.ConfigureExtenstions.AddNLog' is obsolete: instead use ILoggingBuilder.AddNLog() or IHostBuilder.UseNLog().

So I tried to update the method to

private void Configure(IApplicationBuilder app, IWebHostEnvironment env, ILoggingBuilder loggingBuilder)
{
    ...
    loggingBuilder.AddNLog();
    ...
}

or

private void Configure(IApplicationBuilder app, IWebHostEnvironment env, IHostBuilder hostBuilder)
{
    ...
    hostBuilder.UseNLog();
    ...
}

But in both cases I got a DI exception: Could not resolve a service of type {Microsoft.Extensions.Logging.ILoggingBuilder/Microsoft.Extensions.Hosting.IHostBuilder} for the parameter {loggingBuilder/hostBuilder} of method 'Configure' on type 'MyProject.Startup' .

I could not find any viable source on how to change the NLog configuration fro .NET Core 3.0 and there is nothing about logging in the official Microsoft guide . Does anyone know how to solve this issue?

Answer 1

With ASP.NET Core 2+, the pattern to bootstrap an ASP.NET Core site has changed. NLog adapts that. With the latest version of NLog.Extensions.Logging.ConfigureExtenstions , the old methods are made obsolete.

For example, ASP.NET Core nowadays uses a CreateHostBuilder .

I would recommend to follow:

1. Migrate from ASP.NET Core 2.2 to 3.0 | Microsoft Docs
2. And then: Getting started with ASP.NET Core 3 · NLog/NLog Wiki