ASP.NET Core -NLog

1.安装NuGet包

2.准备Nlog的配置文件 nlog.config

<?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"
      throwExceptions="false"
      internalLogLevel="Info" internalLogFile="internal-nlog.txt">

    <!-- 定义日志输出目标 -->
    <targets>
        <target name="FileError" xsi:type="File"  fileName="${basedir}/Logs/Error/${var:logfilename}_Error.txt"
                layout="${longdate} ${level:uppercase=true} ${message} ${exception}" archiveEvery="Day" archiveAboveSize="240" maxArchiveFiles="20" 
                archiveFileName="${basedir}/Log/Error/${var:logfilename}_Error.{#}.txt" />

        <target name="FileWarn" xsi:type="File" fileName="${basedir}/Logs/Warn/${var:logfilename}_Warn.txt" layout="${longdate} ${message}"
                archiveEvery="Day" archiveAboveSize="240" maxArchiveFiles="20" archiveFileName="${basedir}/Log/Warn/${var:logfilename}_Warn.{#}.txt" />
        
        <target name="FileInfo" xsi:type="File" fileName="${basedir}/Logs/Info/${var:logfilename}_Info.txt" layout="${longdate} ${message}"
                archiveEvery="Day" archiveAboveSize="240" maxArchiveFiles="20" archiveFileName="${basedir}/Log/Info/${var:logfilename}_Info.{#}.txt" />
        
        <target name="FileDebug" xsi:type="File" fileName="${basedir}/Logs/Debug/${var:logfilename}_Debug.txt" layout="${longdate} ${message}"
                archiveEvery="Day" archiveAboveSize="240" maxArchiveFiles="20"  archiveFileName="${basedir}/Log/Debug/${var:logfilename}_Debug.{#}.txt"/>
    </targets>

    <!-- 定义日志规则 -->
    <rules>
        <logger name="*" minlevel="Error" maxlevel="Fatal" writeTo="FileError" />
        <logger name="*" minlevel="Warn" maxlevel="Warn" writeTo="FileWarn" />
        <logger name="*" minlevel="Info" maxlevel="Info" writeTo="FileInfo" />
        <logger name="*" minlevel="Debug" maxlevel="Debug" writeTo="FileDebug" />
    </rules>
</nlog>

 3.添加注入NLog服务的扩展

 private static string LogPath
 {
     get
     {
         return Path.Combine(AppContext.BaseDirectory, "nlog.config");
     }
 }
 public static ILoggingBuilder AddNLog(this ILoggingBuilder log,string? filename=null)
 {
     //删除其他的日志记录提供程序
     log.ClearProviders();
     LogManager.Configuration.LogFactory.Setup().LoadConfigurationFromFile(LogPath);
     LogManager.Configuration.Variables["logfilename"] = filename;
     //启用NLog作为日志记录的提供程序
     log.AddNLogWeb(LogManager.Configuration);
     return log;
 }

4.Program.cs注入NLog服务

//日志
builder.Logging.AddNLog();

5.使用

[ApiController]
[Route("[controller]")]
public class UserController(ILogger<UserController> logger) : ControllerBase
{
    [HttpGet("GetUserExit")]
    public void GetUserExit(string account)
    {
        logger.LogInformation("调用方法->GetUserExit");
    }
}

针对无法使用构造函数依赖注入使用日志的，建立如下Helper

public class LogHelper
{
    private static string logPath
    {
        get { return Path.Combine(AppContext.BaseDirectory, "nlog.config"); }
    }

    private static ISetupBuilder _factory = LogManager.Configuration.LogFactory.Setup().LoadConfigurationFromFile(logPath);
    private static Logger _logger = null;
    /// <summary>
    /// 日志操作对象
    /// </summary>
    public static Logger Log
    {
        get
        {
            if (_logger == null) _logger = _factory.LogFactory.GetCurrentClassLogger();
            return _logger;
        }
    }

}

如在Program中调用