log4net的相关使用笔记

1, XmlConfigurator

创建添加一个Tracer project，引用nuget上最新的log4net

在Tracer里新增一个AppLog类：

public static class AppLog
    {
        private static ILog log;

        static AppLog()
        {
            string path = System.IO.Path.Combine(AppDomain.CurrentDomain.SetupInformation.ApplicationBase, "log4net.config");
            XmlConfigurator.ConfigureAndWatch(new FileInfo(path));
            log = LogManager.GetLogger(typeof(AppLog));
            WriteHeaderInfo();
        }

        public static void Debug(object message)
        {
            log.Debug(message);
        }

        public static void Debug(string format, params object[] args)
        {
            log.DebugFormat(format, args);
        }

        public static void Info(object message)
        {
            log.Info(message);
        }

        public static void Info(string format, params object[] args)
        {
            log.InfoFormat(format, args);
        }

        public static void Warn(object message)
        {
            log.Warn(message);
        }

        public static void Warn(object message, Exception exception)
        {
            log.Warn(message, exception);
        }

        public static void WarnFormatted(string format, params object[] args)
        {
            log.WarnFormat(format, args);
        }

        public static void Error(object message)
        {
            log.Error(message);
        }

        public static void Error(object message, Exception exception)
        {
            log.Error(message, exception);
        }

        public static void ErrorFormatted(string format, params object[] args)
        {
            log.ErrorFormat(format, args);
        }

        public static void Fatal(object message)
        {
            log.Fatal(message);
        }

        public static void Fatal(object message, Exception exception)
        {
            log.Fatal(message, exception);
        }

        public static void FatalFormatted(string format, params object[] args)
        {
            log.FatalFormat(format, args);
        }

        /// <summary>
        /// Write the logging header, e.g. some system informations
        /// </summary>
        /// <returns></returns>
        private static void WriteHeaderInfo()
        {
            System.Reflection.Assembly myAssembly = System.Reflection.Assembly.GetExecutingAssembly();
            System.Version appVersion = myAssembly.GetName().Version;
            string strDomainName = string.Empty;
            string strUserName = string.Empty;
            string OSType = Is64BitWindowsOS() ? "64-bit" : "32-bit";
            FileInfo file = new FileInfo(myAssembly.Location);
            string createDate = file.CreationTime.ToString("yyyy-MM-dd HH:mm:ss");

            log.Info("==============================================================================================================");
            log.Info(string.Empty);
            log.Info(string.Format("\t[Version: {0}] Logging started at {1}", appVersion.ToString(), System.DateTime.Now.ToString()));
            log.Info(string.Empty);
            log.Info(string.Format("\tOS Version: {0}({1})\tCLR Version: {2}", System.Environment.OSVersion.ToString(), OSType, System.Environment.Version.ToString()));
            log.Info(string.Format("\tLanguage: {0}\tUI Language: {1}", System.Threading.Thread.CurrentThread.CurrentCulture.DisplayName, System.Threading.Thread.CurrentThread.CurrentUICulture.DisplayName));
            log.Info(string.Format("\tUser Domain: {0}\tUsername(Local Session):   {1}", System.Environment.UserDomainName, System.Environment.UserName));
            log.Info(string.Format("\tUser Domain: {0}\tUsername(Network Session): {1}", strDomainName, strUserName));
            log.Info(string.Format("\tBuild Created Time: {0}", createDate));
            log.Info(string.Empty);
            log.Info("==============================================================================================================");
            log.Info(string.Empty);
        }

        private static bool Is64BitWindowsOS()
        {
            bool is64Bit = false;

            try
            {
                string cpuType = System.Environment.GetEnvironmentVariable("PROCESSOR_ARCHITECTURE");
                string originalCpuTypeOr = System.Environment.GetEnvironmentVariable("PROCESSOR_ARCHITEW6432");
                if (string.Compare(cpuType, "amd64", true) ==  || string.Compare(originalCpuTypeOr, "amd64", true) == )
                {
                    is64Bit = true;
                }
                else
                {
                    is64Bit = false;
                }
            }
            catch (System.Security.SecurityException e)
            {
                System.Diagnostics.Debug.Fail("Cannot detect the process bitness\n" + e.ToString());
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.Fail("Cannot detect the process bitness\n" + ex.ToString());
            }

            return is64Bit;
        }
    }

在Tracer里创建一个log4net.config文件，并且确定这个文件在编译的时候会复制到对应文件夹

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <section name="log4net" type="System.Configuration.IgnoreSectionHandler"/>
  </configSections>
  <log4net>
    <!--配置在root注册的appender-ref具体属性-->
    <appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
      <!--日志文件名开头-->
      <file value="Log\"/>
      <!--是否追加到文件-->
      <appendToFile value="true"/>
      <!--混合使用日期和文件大小变换日志文件名-->
      <rollingStyle value="Composite"/>
      <!--日期的格式-->
      <datePattern value="yyyyMMdd&quot;.txt&quot;"/>
      <!--设置无限备份=-1 ，最大备份数为1000-->
      <maxSizeRollBackups value="500"/>
      <!--最大文件大小，可以使用"KB", "MB" 或 "GB"为 MaxFileSize 作为后缀限定大小。默认的文件大小是10MB-->
      <maximumFileSize value="5MB"/>
      <staticLogFileName value="false"/>
      <!--日志布局-->
      <layout type="log4net.Layout.PatternLayout">
        <!--<conversionPattern value="%date [%thread] %-5level %logger -> %message%newline"/>-->
        <conversionPattern value="%date [%thread] %-5level -> %message%newline"/>
      </layout>
    </appender>
    <root>
      <!--定义Level级别，若没定义，默认为Debug-->
      <level value="All"/>
      <!--定义日志对象使用的appender,通过appeder-ref来注册-->
      <appender-ref ref="RollingLogFileAppender"/>
    </root>
  </log4net>
</configuration>

这样，当其他app想写log，只需要调用AppLog的相关静态方法。

Tracer.AppLog.Debug("User calls method...Interval:{0}ms", Interval);
Tracer.AppLog.Debug("Start！");

2， BasicConfigurator

log4net也支持不用config文件的方式

比如，在上面的例子，我们可以不创建log4net.config文件，并且将AppLog的静态创建方法改写如下：

        static AppLog()
        {
            PatternLayout layout = new PatternLayout("%date{MMM/dd/yyyy HH:mm:ss,fff} [%thread] %-5level %logger %ndc – %message%newline");

            LevelMatchFilter filter = new LevelMatchFilter();
            filter.LevelToMatch = Level.All;
            filter.ActivateOptions();

            RollingFileAppender appender = new RollingFileAppender();
            appender.File = Path.Combine(AppDomain.CurrentDomain.SetupInformation.ApplicationBase, "common.log");
            appender.ImmediateFlush = true;
            appender.AppendToFile = true;
            appender.RollingStyle = RollingFileAppender.RollingMode.Date;
            appender.DatePattern = "-yyyy-MM-dd";
            appender.LockingModel = new FileAppender.MinimalLock();
            appender.Name = string.Format("{0}Appender", "AppLog");
            appender.AddFilter(filter);
            appender.Layout = layout;
            appender.ActivateOptions();

            string repositoryName = string.Format("{0}Repository", "AppLog");
            ILoggerRepository repository = LoggerManager.CreateRepository(repositoryName);
            string loggerName = string.Format("{0}Logger", "AppLog");
            BasicConfigurator.Configure(repository, appender);

            log = LogManager.GetLogger(repositoryName, loggerName);//这是重点

            WriteHeaderInfo();
        }

参考文章：

How to programmatically create log instance by Log4Net library

Apache log4net™ Manual - Configuration

log4net 配置文件配置方法

log4net的各种Appender配置示例