1. Nuget安装log4net，图里的两个

2.项目根目录下添加log4net.config.添加下面的代码:

<?xml version="1.0" encoding="utf-8"?>
<configuration><!-- This section contains the log4net configuration settings --><log4net><appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender"><file value="Log/" /><appendToFile value="true" /><rollingStyle value="Composite" /><staticLogFileName value="false" /><datePattern value="yyyy-MM-dd'.log'" /><maxSizeRollBackups value="10" /><maximumFileSize value="10MB" /><layout type="log4net.Layout.PatternLayout"><conversionPattern value="%date  [%thread]  %-5level  %message%newline" /></layout></appender><!-- Setup the root category, add the appenders and set the default level --><root><level value="ALL" /><appender-ref ref="RollingLogFileAppender" /></root></log4net></configuration>

3. 添加一个logHelper.cs

    public class LogHelper{private static readonly ILog logger;static LogHelper(){if (logger == null){var repository = LogManager.CreateRepository("NETCoreRepository");XmlConfigurator.Configure(repository, new FileInfo("log4net.config"));logger = LogManager.GetLogger(repository.Name, "InfoLogger");}}/// <summary>/// 普通日志/// </summary>/// <param name="message"></param>/// <param name="exception"></param>public static void Info(string message, Exception exception = null){if (exception == null)logger.Info(message);elselogger.Info(message, exception);}/// <summary>/// 告警日志/// </summary>/// <param name="message"></param>/// <param name="exception"></param>public static void Warn(string message, Exception exception = null){if (exception == null)logger.Warn(message);elselogger.Warn(message, exception);}/// <summary>/// 错误日志/// </summary>/// <param name="message"></param>/// <param name="exception"></param>public static void Error(string message, Exception exception = null){if (exception == null)logger.Error(message);elselogger.Error(message, exception);}}

4. 调用:

LogHelper.Info("test Info log");　　   //普通日志
LogHelper.Warn("test Warn log");　     //告警日志
LogHelper.Error("test Error log");　　 //错误日志

项目里就会生成log文件