dotnet6 nlog依赖注入和数据库写入

aspnetcore6,自身携带的四种Logging providers:Console/Debug/EventSource/EventLog (Windows only)

Logging providers - .NET | Microsoft Learn

功能有限，使用专业性更强的第三方logging provider,例如NLog(https://nlog-project.org/)

步骤：

1，创建aspnetcore6 web项目（带控制的webapi或者mvc）后，首先安装 4个依赖包

NLog：　　https://www.nuget.org/packages/NLog/5.0.4

NLog.Web.AspNetCore:　　https://www.nuget.org/packages/NLog.Web.AspNetCore/5.1.0

NLog.Extensions.Logging：　　https://www.nuget.org/packages/NLog.Extensions.Logging/5.0.1

NLog.Database(写入到数据库)：　　https://www.nuget.org/packages/NLog.Database/5.0.4

2，配置appsettings.json (NLog configuration with appsettings.json · NLog/NLog.Extensions.Logging Wiki (github.com))

如果使用nlog.config，nlog5.0版本不再自动加载nlog扩展(Nlog.Database等)，需要配置autoloadExtensions=“true”

<nlog autoloadExtensions="true">
</nlog>

3，Program.cs添加依赖注入

using NLog;
using NLog.Web;

var logger = NLog.LogManager.Setup().LoadConfigurationFromAppSettings().GetCurrentClassLogger();
logger.Debug("init main");

try
{
    var builder = WebApplication.CreateBuilder(args);

    // Add services to the container.
    builder.Services.AddControllersWithViews();

    // NLog: Setup NLog for Dependency injection
    builder.Logging.ClearProviders();
    builder.Host.UseNLog();

    var app = builder.Build();

    // Configure the HTTP request pipeline.
    if (!app.Environment.IsDevelopment())
    {
        app.UseExceptionHandler("/Home/Error");
        // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
        app.UseHsts();
    }

    app.UseHttpsRedirection();
    app.UseStaticFiles();

    app.UseRouting();

    app.UseAuthorization();

    app.MapControllerRoute(
        name: "default",
        pattern: "{controller=Home}/{action=Index}/{id?}");

    app.Run();
}
catch (Exception exception)
{
    // NLog: catch setup errors
    logger.Error(exception, "Stopped program because of exception");
    throw;
}
finally
{
    // Ensure to flush and stop internal timers/threads before application-exit (Avoid segmentation fault on Linux)
    NLog.LogManager.Shutdown();
}

4，注入到控制器

using Microsoft.Extensions.Logging;

public class HomeController : Controller
{
    private readonly ILogger<HomeController> _logger;

    public HomeController(ILogger<HomeController> logger)
    {
        _logger = logger;
        _logger.LogDebug(1, "NLog injected into HomeController");
    }

    public IActionResult Index()
    {
        _logger.LogInformation("Hello, this is the index!");
        return View();
    }
}