ASP.NET Core使用log4net记录日志

　　干粮直接上……

　　新建一个ASP.NET项目，并添加log4net.config文件，且log4net.config文件配置如下所示：

<?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="yyyyMMdd'.log'" />
<maxSizeRollBackups value="10" />
<maximumFileSize value="50MB" />
<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>

　　接下来编写一个记录日志的公共类代码如下：

public class Logger
{
private static ILog logger;
static Logger()
{
if (logger == null)
{
var repository = LogManager.CreateRepository("NETCoreRepository");
//log4net从log4net.config文件中读取配置信息
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);
else
logger.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);
else
logger.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);
else
logger.Error(message, exception);
}
}

　　接下来就是在任意控制器或者类中使用刚编写的Logger类来记录日志到文件中

[HttpPost("list")]
public async Task<IActionResult> CarList()
{
var msg = await service.GetCarList(Request);
Logger.Info(JsonConvert.SerializeObject(msg));//此处调用日志记录函数记录日志
return Json(msg);
}

　　记录的日子在Log文件目录中：

打开文件查看日志内容如下所示：

注意，如果Logger类中抛出FileNotFoundException异常，说明目录下未找到log4net.config文件，这时请在项目log4net.config文件上右键——属性——将“复制到输出目录”项的值改为“始终复制”即可。