.Net Core 使用NLog記錄日志到文件和數(shù)據(jù)庫的操作方法

更新時間：2021年07月14日 10:33:05 作者：慕夜h

這篇文章主要介紹了.Net Core 使用NLog記錄日志到文件和數(shù)據(jù)庫的操作方法,本文分步驟通過實例代碼給大家介紹的非常詳細，需要的朋友可以參考下

NLog 記錄日志是微軟官方推薦使用。

接下來，通過配置日志記錄到文件和Sql Server數(shù)據(jù)庫。

第一步：首先添加包NLog.Config （可通過微軟添加包命令Install-Package 包名進行添加，也可以通過管理NuGet程序包進行添加），添加成功后會生成NLog.config配置文件。并對該配置文件進行配置。詳細配置可參考Git上 NLog說明。

一下是我個人配置。

 <?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"
        xsi:schemaLocation="http://www.nlog-project.org/schemas/NLog.xsd NLog.xsd"
        autoReload="true"
        throwExceptions="false"
        internalLogLevel="Warn"   
        internalLogFile="Logs/nlog-internal.log">
    
   <!--internalLogLevel="Off"-->
   <!-- optional, add some variables
   https://github.com/nlog/NLog/wiki/Configuration-file#variables
   -->
   <variable name="myvar" value="myvalue"/>
 
   <!--
   See https://github.com/nlog/nlog/wiki/Configuration-file
   for information on customizing logging rules and outputs.
    -->
   <targets>
 
     <!--
     add your targets here
     See https://github.com/nlog/NLog/wiki/Targets for possible targets.
     See https://github.com/nlog/NLog/wiki/Layout-Renderers for the possible layout renderers.
     -->
 
     <!--
     Write events to a file with the date in the filename.
     <target xsi:type="File" name="f" fileName="${basedir}/logs/${shortdate}.log"
             layout="${longdate} ${uppercase:${level}} ${message}" />
     -->
 
     <!-- write logs to file -->
     <target xsi:type="File" name="allfile" fileName="Logs/${date:format=yyyyMM}/nlog-all-${shortdate}.log"
              layout="${longdate}|${event-properties:item=EventId.Id}|${uppercase:${level}}|${logger} ${newline}${message} ${exception} ${newline}" />
 
     <target xsi:type="File" name="ownFile-web" fileName="Logs/${date:format=yyyyMM}/nlog-own-${shortdate}.log"
              layout="${longdate}|${event-properties:item=EventId.Id}|${uppercase:${level}}|${logger} ${newline}${message} ${exception} ${newline} --- |url: ${aspnet-request-url}|action: ${aspnet-mvc-action}" />
 
     <target xsi:type="Null" name="blackhole" />
 
     <target xsi:type="Database" name="database">
       <connectionString>${var:connectionString}</connectionString>
       <commandText>
         insert into syslogs (Application,Levels,Operatingtime,Operatingaddress,Userid,Logger,Callsite,Requesturl,Referrerurl,Action,Message,Exception)
         values (@application,@levels,@operatingtime,@operatingaddress,@userid,@logger,@callSite,@requesturl,@referrerurl,@action,@message,@exception);
       </commandText>
       <parameter name="@application" layout="WebApi" />
       <parameter name="@levels" layout="${level}" />
       <parameter name="@operatingTime" layout="${date}" />
       <parameter name="@operatingaddress" layout="${aspnet-Request-IP}" />
       <parameter name="@userid" layout="1" />
       <parameter name="@logger" layout="${logger}" />
       <parameter name="@callSite" layout="${callsite}" />
       <parameter name="@requesturl" layout="${aspnet-request-url}" />
       <parameter name="@referrerurl" layout="${aspnet-request}" />
       <parameter name="@action" layout="${aspnet-mvc-action}" />
       <parameter name="@message" layout="${message}" />
       <parameter name="@exception" layout="${exception:tostring}" />
     </target>
     
   </targets>
 
   <rules>
     <!-- add your logging rules here -->
 
     <!--
     Write all events with minimal level of Debug (So Debug, Info, Warn, Error and Fatal, but not Trace)  to "f"
     <logger name="*" minlevel="Debug" writeTo="f" />
     -->
 
     <!--All logs, including from Microsoft-->
     <!--minlevel 改為Trace 跟蹤全部 Error 只捕獲異常-->
     <logger name="*" minlevel="Error" writeTo="allfile" />
 
     <!--Skip Microsoft logs and so log only own logs-->
     <logger name="Microsoft.*" minlevel="Trace" writeTo="blackhole" final="true" />
     <logger name="*" minlevel="Trace" writeTo="ownFile-web" />
     <logger name="*" minlevel="Trace" writeTo="database" />    
     
   </rules>
 </nlog>
 
 
 <!--增加引用
 <PackageReference Include="NLog.Extensions.Logging" Version="1.2.1" />
 <PackageReference Include="NLog.Web.AspNetCore" Version="4.6.0" />-->

說明：targets 中有一節(jié)點為Database，是配置將日志寫入數(shù)據(jù)庫中，注意需要在數(shù)據(jù)庫中添加該記錄日志表。

{
  "ConnectionStrings": {
    "DefaultConnection": "Data Source=192.168.30.133;Initial Catalog=Test;User ID=sa;Password=123456;Trusted_Connection=True;MultipleActiveResultSets=true;Integrated Security=false;"
  },
  "Logging": {
    "LogLevel": {
      "Default": "Warning"
    }
  },
  "AllowedHosts": "*"
}

第二步：添加包NLog.Web.AspNetCore，在Program.cs中的WebHost加入".UseNLog()"（該屬于程序集NLog.Web，需要添加引用using NLog.Web;）,即為添加nlog.

using Microsoft.AspNetCore;
using Microsoft.AspNetCore.Hosting;
using NLog.Web;

namespace WebApi
{
    public class Program
    {
        public static void Main(string[] args)
        {
            CreateWebHostBuilder(args).Build().Run();
        }

        public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
            WebHost.CreateDefaultBuilder(args)
                .UseStartup<Startup>()
                .UseNLog(); //加入nlog日志
    }
}

第三步：在Startup.cs中的Configure方法中添加記日志代碼，即需要加載的配置文件和配置日志寫入數(shù)據(jù)庫連接字符串代碼。注意：為避免中文亂碼問題需要添加System.Text.Encoding.CodePages包。

  public void Configure(IApplicationBuilder app, IHostingEnvironment env)
          {
  
              #region Nlog記日志
              //將日志記錄到數(shù)據(jù)庫                 config/NLog.config
              NLog.LogManager.LoadConfiguration("nlog.config").GetCurrentClassLogger();       NLog.LogManager.Configuration.Variables["connectionString"] = Configuration.GetConnectionString("DefaultConnection");   Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);  //避免日志中的中文輸出亂碼
              #endregion
 
             if (env.IsDevelopment())
                 app.UseDeveloperExceptionPage();
             else
                 app.UseHsts();
   app.UseHttpsRedirection();
 
             app.UseMvc();
         }

第四步：使用微軟推薦的方式在在構(gòu)造方法中將將日志對象注入。

public class UsersController : Controller
    {
        /// <summary>
        /// 日志對象
        /// </summary>
        private readonly ILogger logger;    
         public UsersController(ILoggerFactory loggerFactory)
        {
            this.logger = loggerFactory.CreateLogger<UsersController>();

            #region 測試日志
            logger.LogTrace("開發(fā)階段調(diào)試，可能包含敏感程序數(shù)據(jù)", 1);
            logger.LogDebug("開發(fā)階段短期內(nèi)比較有用，對調(diào)試有益。");
            logger.LogInformation("你訪問了首頁。跟蹤程序的一般流程。");
            logger.LogWarning("警告信息！因程序出現(xiàn)故障或其他不會導致程序停止的流程異常或意外事件。");
            logger.LogError("錯誤信息。因某些故障停止工作");
            logger.LogCritical("程序或系統(tǒng)崩潰、遇到災難性故障?。?！");
            #endregion
        }

所有工作完成，運行程序。在配置NLog路徑下生成日志文件，同時，在數(shù)據(jù)庫中生成日志。