用TextWriterTraceListener实现建议log文件记录

log4net之类3方组件确实很方便，但是想写个小小的demo之类的程序，有点用不起啊。

微软自带的TraceListener要实现一个简易的日志帮助类还是很简单的，直接上代码，自己备用，也希望对同样烦恼的哥们有用：

using System;using System.Collections.Generic;using System.IO;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Diagnostics;namespace TestExPRessionLambda{    public class Logger    {        /// <summary>        /// 默认路径        /// </summary>        public static readonly string RootPath = AppDomain.CurrentDomain.BaseDirectory + "log";        /// <summary>        /// 默认文件名格式        /// </summary>        public static readonly string FileFormat = DateTime.Now.ToString("yyyy-MM-dd") + ".log";        /// <summary>        /// 默认Trace监听        /// </summary>        public static TextWriterTraceListener traceListener;        /// <summary>        /// 静态实例        /// </summary>        private static readonly Logger instance = new Logger();        static Logger()        {            if (!Directory.Exists(RootPath))            {                Directory.CreateDirectory(RootPath);            }            string logFile = RootPath.TrimEnd('//') + "//" + FileFormat;            //if (!File.Exists(logFile))            //{            //    File.Create(logFile);            //}            //这里不用create文件，TextWriterTraceListener会自动创建了,谢谢楼下的哥们            Trace.AutoFlush = true;            traceListener = new TextWriterTraceListener(logFile);            Trace.Listeners.Add(traceListener);        }        /// <summary>        /// log输出　　　　 /// 当然这里可以自己随便扩充        /// </summary>        /// <param name="msg"></param>        public static void Log(string msg)        {            Trace.WriteLine(msg);        }    }}