前置：为项目安装如下两个依赖 

1.创建文件夹cfgFile

2.创建log4net.Config

<?xml version="1.0" encoding="utf-8" ?>
<log4net><appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender"><layout type="log4net.Layout.PatternLayout"><conversionPattern value="%date [%thread] %-5level %logger - %message%newline" /></layout></appender><appender name="FileAppender" type="log4net.Appender.FileAppender"><!--文件地址--><file value="logs/log-file.txt" /><!--追加日志内容--><appendToFile value="true" /><!--多线程--><lockingModel type="log4net.Appender.FileAppender+MinimalLock"/><layout type="log4net.Layout.PatternLayout"><conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" /></layout></appender><appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender"><file value="logs/LogFile/Error/" /><appendToFile value="true" /><rollingStyle value="Composite" /><datePattern value="yyyyMMdd'.log'" /><maxSizeRollBackups value="20" /><maximumFileSize value="3MB" /><staticLogFileName value="false" /><layout type="log4net.Layout.PatternLayout"><conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" /></layout><filter type="log4net.Filter.LevelRangeFilter"><levelMin value="ERROR" /><levelMax value="FATAL" /></filter></appender><appender name="WarnRollingFileAppender" type="log4net.Appender.RollingFileAppender"><file value="logs/LogFile/Warn/" /><appendToFile value="true" /><rollingStyle value="Date" /><datePattern value="yyyy-MM-dd'.log'" /><encoding value="utf-8" /><layout type="log4net.Layout.PatternLayout"><conversionPattern value="%newline%date [%thread %-5level] %n -- %m%n" /></layout><filter type="log4net.Filter.LevelRangeFilter"><levelMin value="WARN" /><levelMax value="WARN" /></filter></appender><appender name="InfoRollingFileAppender" type="log4net.Appender.RollingFileAppender"><file value="logs/LogFile/Info/" /><appendToFile value="true" /><rollingStyle value="Date" /><datePattern value="yyyy-MM-dd'.log'" /><layout type="log4net.Layout.PatternLayout"><conversionPattern value="%newline%date [%thread %-5level] %n %m%n" /></layout><filter type="log4net.Filter.LevelRangeFilter"><levelMin value="INFO" /><levelMax value="INFO" /></filter></appender><root><level value="ALL" /><appender-ref ref="ConsoleAppender" /><appender-ref ref="FileAppender" /><appender-ref ref="RollingLogFileAppender" /><appender-ref ref="WarnRollingFileAppender" /><appender-ref ref="InfoRollingFileAppender" /></root>
</log4net>

3.使用日志

Program.cs->添加配置

//日志
builder.Logging.AddLog4Net("CfgFile/log4net.Config");

配置位置tips： 

4.通过构造函数注入日志在控制器中

//UsersController控制器中
private readonly ILogger<UsersController> _logger;public UsersController(ILogger<UsersController> logger){_logger = logger;}

配置位置tips：  

5.使用日志

 _logger.LogInformation("这是一个Get请求");

配置位置tips：  

6.测试日志是否成功

执行项目

• 查看bin文件夹下是否多了下面的目录

• 调用Get命令，查看在输出中是否有刚才那段日志

ok,日志配置成功~~