ASP.NET Core中使用NLog记录日志

直接在NuGet里面搜索NLog.Web.AspNetCore

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>();
        //           webBuilder.UseNLog();
        //       });

        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup<Startup>();
                }).UseNLog();
        //鼠标放在UseNLog() 会显示是IHostBuilder的拓展方法IHostBuilder.UseNlog()
    }

<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      autoReload="true"
      throwConfigExceptions="true"
      internalLogLevel="info"
      internalLogFile="E:\log\internal-nlog.txt">
  <!--autoReload：修改后自动加载，可能会有延迟-->
  <!--throwConfigExceptions：NLog日志系统抛出异常-->
  <!--internalLogLevel：内部日志的级别-->
  <!--internalLogFile：内部日志保存路径，日志的内容大概就是NLog的版本信息，配置文件的地址等等-->
  <!--输出日志的配置，用于rules读取-->
  <targets>
    <!--write logs to file-->
    <!--将日志写入文件中,fileName可以指定日志生成的路径-->
    <target xsi:type="File" name="allfile" fileName="D:\Log\nlog-all-${shortdate}.log"
             layout="${longdate}|${logger}|${uppercase:${level}}|${message} ${exception}" />
     <!--同样是将文件写入日志中，写入的内容有所差别，差别在layout属性中体现。写入日志的数量有差别，差别在路由逻辑中体现-->
    <target xsi:type="File" name="ownFile-web" fileName="D:\Log\nlog-my-${shortdate}.log"
             layout="${longdate}|${logger}|${uppercase:${level}}|${message} ${exception}" />
    <target xsi:type="Null" name="blackhole" />
  </targets>
  <rules>
    <!--路由顺序会对日志打印产生影响。路由匹配逻辑为顺序匹配。-->
    <!--All logs, including from Microsoft-->
    <logger name="*" minlevel="Trace" writeTo="allfile" />

    <!--Skip Microsoft logs and so log only own logs-->
    <!--以Microsoft打头的日志将进入此路由，由于此路由没有writeTo属性，所有会被忽略-->
    <!--且此路由设置了final，所以当此路由被匹配到时。不会再匹配此路由下面的路由。未匹配到此路由时才会继续匹配下一个路由-->
    <logger name="Microsoft.*" minlevel="Trace"  final="true" />
    <!--上方已经过滤了所有Microsoft.*的日志，所以此处的日志只会打印除Microsoft.*外的日志-->
    <logger name="*" minlevel="Trace" writeTo="ownFile-web" />
  </rules>
</nlog>

[ApiController]
    [Route("[controller]")]
    public class WeatherForecastController : ControllerBase
    {
        private static readonly string[] Summaries = new[]
        {
            "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"
        };

        private readonly ILogger<WeatherForecastController> _logger;
        private readonly IConfiguration Configuration;

        public WeatherForecastController(ILogger<WeatherForecastController> logger, IConfiguration configuration)
        {
            _logger = logger;
            Configuration = configuration;
        }

        [HttpGet]
        public IEnumerable<WeatherForecast> Get()
        {
            _logger.LogError("这是错误信息");
            _logger.LogDebug("这是调试信息");
            _logger.LogInformation("这是提示信息");
            
            try
            {
                throw new Exception("BOBOBOBOBBBBBBBBBBexection");
            }
            catch (Exception ex)
            {
                _logger.LogInformation("这是提示信息"+ ex.Message);
               
            }
            var rng = new Random();
            return Enumerable.Range(1, 5).Select(index => new WeatherForecast
            {
                Date = DateTime.Now.AddDays(index),
                TemperatureC = rng.Next(-20, 55),
                Summary = Summaries[rng.Next(Summaries.Length)]
            })
            .ToArray();
        }
    }