c#: 简单的日志管理类(TextWriterTraceListener)

以c#实现轻量级的日志管理，着实简单，置一静态类记之：

    /// <summary>

    /// 日志管理

    /// </summary>

    public static class LogHelper

    {

        //超过3M则清除

        const int MAX_LOG_SIZE =  *  * ;

        public static void Init(string fileName)

        {

            CheckAndCleanLogFile(fileName);

            bool firstWrite = !File.Exists(fileName);

            var traceListener = new TimeTextWriterTraceListener(fileName);

            //TraceOptions.DateTime，在以Trace.TraceError、Trace.TraceWarning等方式输出信息时，全加入日期信息

            traceListener.TraceOutputOptions |= TraceOptions.DateTime;

            Trace.Listeners.Add(traceListener);

            Trace.AutoFlush = true;

            //初始日志

            if (firstWrite)

                Trace.WriteLine(string.Format("OS Version: {0}", Environment.OSVersion.ToString()));

            Trace.WriteLine("\r\n" + new string('-', ));

            Trace.WriteLine(string.Format("Program Start: {0} v{1}", Application.ProductName, Application.ProductVersion));

        }

        private static void CheckAndCleanLogFile(string fileName)

        {

            if (!File.Exists(fileName))

                return;

            try

            {

                var fi = new FileInfo(fileName);

                if (fi.Length > MAX_LOG_SIZE)

                    File.Delete(fileName);

            }

            catch

            {

            }

        }

        private class TimeTextWriterTraceListener : TextWriterTraceListener

        {

            public TimeTextWriterTraceListener(string fileName)

                : base(fileName)

            {

            }

            public override void WriteLine(string message)

            {

                if (string.IsNullOrEmpty(message))

                    return;

                if ((this.TraceOutputOptions & TraceOptions.DateTime) == TraceOptions.DateTime && !message.Contains("--------"))

                    base.Write(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") + " ");

                base.WriteLine(message);

            }

        }

    }

使用方法：

string logFile = Path.ChangeExtension(Process.GetCurrentProcess().MainModule.FileName, ".log");

LogHelper.Init(logPath);

那么，程序中所有Trace.xxx输出的信息，就都会被记录下来。