动态创建log4net 实例

https://www.cnblogs.com/-dawn/p/8598566.html

根据业务类型，动态的创建日志实例，将日志写到不同目录。常见的配置文件中统一配置，不能满足需求。

• 引用log4net

nuget安装命令： Install-Package log4net -Version 2.0.8

• 日志实例创建类

我这里log实例的相关参数都是直接写死的，你可以根据需要读取配置文件。参数都配有备注，更多参数的含义，网上都可以搜到。

public class GetLog4netInstance
    {

        private static Dictionary<string, ILog> Logers = new Dictionary<string, ILog>();

        /// <summary>
        /// 获取log实例
        /// </summary>
        /// <param name="name"></param>
        /// <returns></returns>
        public static ILog GetLogger(string name)
        {
            if (Logers.ContainsKey(name))
                return Logers[name];
            else
            {
                lock (Logers)
                {
                    if (Logers.ContainsKey(name)) return Logers[name];
                    else
                    {
                        var newLoger = CreateLogerInstance(name);
                        Logers.Add(name, newLoger);
                        return newLoger;
                    }
                }
            }
        }

        /// <summary>
        /// 创建Log实例
        /// </summary>
        /// <param name="name"></param>
        /// <returns></returns>
        private static ILog CreateLogerInstance(string name)
        {
            // Pattern Layout
            PatternLayout layout = new PatternLayout("%date{yyyy-MM-dd HH:mm:ss} %-5level[%L] %message% %F%newline");
            // Level Filter
            LevelMatchFilter filter = new LevelMatchFilter();
            filter.LevelToMatch = Level.All;
            filter.ActivateOptions();
            // File Appender
            RollingFileAppender appender = new RollingFileAppender();
            // 目录
            appender.File = $"logs\\{name}\\";
            // 立即写入磁盘
            appender.ImmediateFlush = true;
            // true：追加到文件；false：覆盖文件
            appender.AppendToFile = true;
            // 新的日期或者文件大小达到上限，新建一个文件
            appender.RollingStyle = RollingFileAppender.RollingMode.Composite;
            // 文件大小达到上限，新建文件时，文件编号放到文件后缀前面
            appender.PreserveLogFileNameExtension = true;
            // 时间模式
            appender.DatePattern = $"yyyyMMdd'.txt'";
            // 最小锁定模型以允许多个进程可以写入同一个文件
            appender.LockingModel = new FileAppender.MinimalLock();
            appender.Name = $"{name}Appender";
            appender.AddFilter(filter);
            appender.Layout = layout;
            appender.ActivateOptions();
            // 文件大小上限
            appender.MaximumFileSize = "200MB";
            // 设置无限备份=-1 ，最大备份数为30
            appender.MaxSizeRollBackups = 30;
            appender.StaticLogFileName = false;
            //create instance
            string repositoryName = $"{name}Repository";
            ILoggerRepository repository = LoggerManager.CreateRepository(repositoryName);
            BasicConfigurator.Configure(repository, appender);
            //After the log instance initialization, we can get the instance from the LogManager by the special log instance name. Then you can start your logging trip.
            ILog logger = LogManager.GetLogger(repositoryName, name);
            return logger;
        }
    }

• 调用实例。

创建实例的时候，相关参数直接写死了，所以不需要写配置文件。引用log4net以后，直接调用即可。

static void Main(string[] args)
        {

            var AccountLoger = GetLog4netInstance.GetLogger("Account");
            var BalanceLoger = GetLog4netInstance.GetLogger("Balance");

            int i = 0;
            while (i < 500)
            {
                BalanceLoger.Debug(i);
                AccountLoger.Debug(i);
                i++;
            }

            Console.WriteLine("结束！");
            Console.ReadKey();

        }

参考：
["How to programmatically create log instance by Log4Net library"][1]
[1]: https://blogs.perficient.com/delivery/blog/2016/04/20/how-to-programmatically-create-log-instance-by-log4net-library/ "How to programmatically create log instance by Log4Net library"