.Net Core 实践 - 使用log4net记录日志（2）

实现目标：将log4net的相关操作封装成一个 .net standard类库
demo地址：https://github.com/puzzledalien/log4net_demo/tree/master/dotnetcoreconsole_v2

step 1 建立解决方案和处理项目相关配置

在当前解决方案下新建项目，选择 .net standard类库，命名“mylogmanager”

nuget引用log4net，添加log4net.config配置，右键点击log4net.config，选择“属性”，修改log4net.config文件属性
刚添加的log4net.config文件属性可能如下图所示（生成操作为无，不复制到输出目录）

需要修改成如下所示（生成操作 无 改为 内容 ，复制到输出目录 - 选择 如果较新则复制）

重新生成解决方案后，在生成目录中就能看到log4net.config文件

step 2 上代码

思路：两个startlogger方法，在程序启动时启动该方法，一个方法自己配置处理，一个走默认
代码如下

    public class mylogmanager
    {
        private static iloggerrepository _loggerrepository;

        /// <summary>
        /// 启动logger
        /// </summary>
        /// <param name="repository">repository名称</param>
        /// <param name="filename">配置文件名称</param>
        public static void startlogger(string repository, string filename)
        {
            _loggerrepository = logmanager.createrepository(repository);
            xmlconfigurator.configureandwatch(_loggerrepository, new fileinfo(filename));
        }

        /// <summary>
        /// 启动logger
        /// </summary>
        public static void startlogger()
        {
            _loggerrepository = logmanager.createrepository(nameof(mylogmanager));
            xmlconfigurator.configureandwatch(_loggerrepository, new fileinfo("log4net.config"));
        }

        public static ilog getmylog<t>(t t)
        {
            return logmanager.getlogger(_loggerrepository.name, t.gettype());
        }

        public static ilog getmylog(object obj)
        {
            return logmanager.getlogger(_loggerrepository.name, obj.gettype());
        }

        public static ilog getmylog(type type)
        {
            return logmanager.getlogger(_loggerrepository.name, type);
        }
    }

封装之后，调用代码会比第一版本的稍微精简

        static void testv1()
        {
            mylogmanager.mylogmanager.startlogger("dotnetcoreconsole_v2", "log4net.config");

            var log = mylogmanager.mylogmanager.getmylog(typeof(program));

            const int numberofcycles = 20000;

            var sw = stopwatch.startnew();
            for (var i = 0; i < numberofcycles; i++)
            {
                log.infoformat("testnum: {0} ", i);
            }
            sw.stop();

            console.writeline();
            console.writeline("ellapsed: {0}, numpersec: {1}", sw.elapsedmilliseconds, numberofcycles / (sw.elapsedmilliseconds / (double)1000));
            console.readkey();
        }

代码重构和优化

思考：可不可以去掉startlogger这行代码呢？可以。
实现如下

    public class nulllogmanager
    {
        private static iloggerrepository _loggerrepository;

        private static iloggerrepository loggerrepository
        {
            get
            {
                if (_loggerrepository != null)
                {
                    return _loggerrepository;
                }
                _loggerrepository = logmanager.createrepository(nameof(nulllogmanager));
                xmlconfigurator.configureandwatch(_loggerrepository, new fileinfo("log4net.config"));
                return _loggerrepository;
            }
        }

        public static ilog getmylog<t>(t t)
        {
            return logmanager.getlogger(loggerrepository.name, t.gettype());
        }

        public static ilog getmylog(object obj)
        {
            return logmanager.getlogger(loggerrepository.name, obj.gettype());
        }

        public static ilog getmylog(type type)
        {
            return logmanager.getlogger(loggerrepository.name, type);
        }

        public static ilog getmylog()
        {
            return logmanager.getlogger(loggerrepository.name, nameof(getmylog));
        }
    }

调用代码可再次精简

        static void testnulllogmanager()
        {
            var log = mylogmanager.nulllogmanager.getmylog(typeof(program));

            const int numberofcycles = 20000;

            var sw = stopwatch.startnew();
            for (var i = 0; i < numberofcycles; i++)
            {
                log.infoformat("testnum: {0} ", i);
            }
            sw.stop();

            console.writeline();
            console.writeline("ellapsed: {0}, numpersec: {1}", sw.elapsedmilliseconds, numberofcycles / (sw.elapsedmilliseconds / (double)1000));
            console.readkey();
        }