.NET Core 支持适用于各种内置和第三方日志记录提供程序的日志记录 API。 先来看下如何将日志记录 API 与内置提供程序一起使用。
调用 CreateDefaultBuilder，这将添加以下日志记录提供程序：
控制台
调试
EventSource
EventLog：仅限 Windows
public class Program
{
public static void Main(string[] args)
{
CreateHostBuilder(args).Build().Run();
}
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup<Startup>();
});
}
若要替代Host.CreateDefaultBuilder 添加的默认日志记录提供程序集，请调用 ClearProviders 并添加所需的日志记录提供程序。 例如，以下代码：
调用 ClearProviders 以从生成器中删除所有 ILoggerProvider 实例。
添加控制台日志记录提供程序。
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureLogging(logging =>
{
logging.ClearProviders();
logging.AddConsole();
})
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup<Startup>();
});
使用第三方替代，以Nlog为例
修改 program.cs
using System;
using NLog.Web;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Hosting;
public static void Main(string[] args)
{
var logger = NLog.Web.NLogBuilder.ConfigureNLog("nlog.config").GetCurrentClassLogger();
try
{
logger.Debug("init main");
CreateHostBuilder(args).Build().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();
}
}
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup<Startup>();
})
.ConfigureLogging(logging =>
{
logging.ClearProviders();
logging.SetMinimumLevel(Microsoft.Extensions.Logging.LogLevel.Trace);
})
.UseNLog(); // NLog: Setup NLog for Dependency injection
写日志
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();
}
