c# - c# 创建日志文件的最佳方法

Question

我正在编写一个工具，它将通过网络检查工作站的健康状况，并根据它发现的问题进行修复。我想创建一个日志文件，因为应用程序在每台机器上运行其任务/检查。我现在只想让它在一台机器上工作，但随着时间的推移，它将一次扫描 100 多台机器（线程已结束）。

创建日志文件的最佳方法是什么？

我正在考虑使用 aList<string>在内存中建立日志文件，然后在完成后将其输出到文件中。

我只是在想可能有更好的方法来做到这一点？

Answer 1

我会推荐log4net。

您将需要多个日志文件。所以多个文件附加程序。另外，您可以动态创建文件附加程序。

示例代码：

using log4net;
using log4net.Appender;
using log4net.Layout;
using log4net.Repository.Hierarchy;

// Set the level for a named logger
public static void SetLevel(string loggerName, string levelName)
{
    ILog log = LogManager.GetLogger(loggerName);
    Logger l = (Logger)log.Logger;

    l.Level = l.Hierarchy.LevelMap[levelName];
    }

// Add an appender to a logger
public static void AddAppender(string loggerName, IAppender appender)
{
    ILog log = LogManager.GetLogger(loggerName);
    Logger l = (Logger)log.Logger;

    l.AddAppender(appender);
}

// Create a new file appender
public static IAppender CreateFileAppender(string name, string fileName)
{
    FileAppender appender = new
        FileAppender();
    appender.Name = name;
    appender.File = fileName;
    appender.AppendToFile = true;

    PatternLayout layout = new PatternLayout();
    layout.ConversionPattern = "%d [%t] %-5p %c [%x] - %m%n";
    layout.ActivateOptions();

    appender.Layout = layout;
    appender.ActivateOptions();

    return appender;
}

// In order to set the level for a logger and add an appender reference you
// can then use the following calls:
SetLevel("Log4net.MainForm", "ALL");
AddAppender("Log4net.MainForm", CreateFileAppender("appenderName", "fileName.log"));

// repeat as desired

来源/良好链接：

Log4Net：以编程方式指定多个记录器（带有多个文件附加器）

以编程方式添加附加程序

如何从头开始以编程方式配置 log4net（无配置）

此外，log4net 还允许写入事件日志。一切都是基于配置的，配置也可以在运行时从 xml 动态加载。

编辑2：

动态切换日志文件的一种方法：Log4Net 配置文件支持环境变量：

Environment.SetEnvironmentVariable("log4netFileName", "MyApp.log");

在 log4net 配置中：

<param name="File" value="${log4netFileName}".log/>

Answer 2

我不会使用第三方库，我会登录到 xml 文件。

这是一个从不同线程记录到 xml 文件的代码示例：

private static readonly object Locker = new object();
private static XmlDocument _doc = new XmlDocument();

static void Main(string[] args)
{
    if (File.Exists("logs.txt"))
        _doc.Load("logs.txt");
    else
    {
        var root = _doc.CreateElement("hosts");
        _doc.AppendChild(root);
    }

    for (int i = 0; i < 100; i++)
    {
        new Thread(new ThreadStart(DoSomeWork)).Start();
    }
}

static void DoSomeWork()
{
    /*
     * Here you will build log messages
     */
    Log("192.168.1.15", "alive");
}

static void Log(string hostname, string state)
{
    lock (Locker)
    {
        var el = (XmlElement)_doc.DocumentElement.AppendChild(_doc.CreateElement("host"));
        el.SetAttribute("Hostname", hostname);
        el.AppendChild(_doc.CreateElement("State")).InnerText = state;
        _doc.Save("logs.txt");
    }
}

Answer 3

You might want to use the Event Log ! Here's how to access it from C# http://support.microsoft.com/kb/307024/en

But whatever is the method that you will use, I'd recommend to output to a file every time something is appended to the log rather than when your process exits, so you won't lose data in the case of crash or if your process is killed.

Answer 4

使用 Nlog http://nlog-project.org/。它是免费的，允许写入文件、数据库、事件日志和其他 20 多个目标。另一个日志框架是 log4net - http://logging.apache.org/log4net/（从 java Log4j 项目移植）。它也是免费的。

最佳实践是使用通用日志记录 - http://commons.apache.org/logging/ 因此您可以稍后将 NLog 或 log4net 更改为其他日志记录框架。

Answer 5

我们对日志记录进行了大量研究，并认为 NLog 是最好的。

见http://nlog-project.org/

另请参阅log4net 与 Nlog 和http://www.dotnetlogging.com/comparison/

Answer 6

您可以使用Apache log4net 库：

using System;
using log4net;
using log4net.Config;


public class MyApp
{
    // Define a static logger variable so that it references the
    // Logger instance named "MyApp".
    private static readonly ILog log = LogManager.GetLogger(typeof(MyApp));
    static void Main(string[] args)
    {
        XmlConfigurator.Configure(new System.IO.FileInfo(@"..\..\resources\log4net.config"));
        log.Info("Entering application.");
        Console.WriteLine("starting.........");
        log.Info("Entering application.");
        log.Error("Exiting application.");
        Console.WriteLine("starting.........");
    }
}

Answer 7

添加这个配置文件

---

*************************************************************************************
<!--Configuration for file appender-->

<configuration>
  <configSections>
    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
  </configSections>
  <log4net>
    <appender name="FileAppender" type="log4net.Appender.FileAppender">
      <file value="logfile.txt" />
      <appendToFile value="true" />
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%d [%t] %-5p [%logger] - %m%n" />
      </layout>
    </appender>
    <root>
      <level value="DEBUG" />
      <appender-ref ref="FileAppender" />
    </root>
  </log4net>
</configuration>

*************************************************************************************

<!--Configuration for console appender-->


<configuration>

  <configSections>
    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,
        log4net" />
  </configSections>

  <log4net>
    <appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender" >
      <layout type="log4net.Layout.PatternLayout">
        <param name="ConversionPattern" value="%d [%t] %-5p [%logger] - %m%n" />
      </layout>
    </appender>
   <root>
      <level value="ALL" />
      <appender-ref ref="ConsoleAppender" />
    </root>
  </log4net>
</configuration>

Answer 8

您还可以查看内置的 .NET 跟踪工具。有一组跟踪侦听器允许您输出到日志文件，但您可以将其配置为登录到事件查看器或数据库（或同时登录到所有数据库）。

http://www.codeguru.com/csharp/.net/net_debugging/tracing/article.php/c5919/NET-Tracing-Tutorial.htm

Answer 9

You can use http://logging.apache.org/ library and use a database appender to collect all your log info together.

Answer 10

我正在使用线程安全的静态类。主要思想是将消息排队在列表中，然后在每个时间段或每个计数器限制中保存到日志文件。

DirectLog.SaveToFile();重要提示：您应该在退出程序时强制保存文件 ( )。（如果列表中还有一些项目）

使用非常简单：DirectLog.Log("MyLogMessage", 5);

这是我的代码：

using System;
using System.IO;
using System.Collections.Generic;

namespace Mendi
{

    /// <summary>
    /// class used for logging misc information to log file
    /// written by Mendi Barel
    /// </summary>
    static class DirectLog
    {
        readonly static int SAVE_PERIOD = 10 * 1000;// period=10 seconds
        readonly static int SAVE_COUNTER = 1000;// save after 1000 messages
        readonly static int MIN_IMPORTANCE = 0;// log only messages with importance value >=MIN_IMPORTANCE

        readonly static string DIR_LOG_FILES = @"z:\MyFolder\";

        static string _filename = DIR_LOG_FILES + @"Log." + DateTime.Now.ToString("yyMMdd.HHmm") + @".txt";

        readonly static List<string> _list_log = new List<string>();
        readonly static object _locker = new object();
        static int _counter = 0;
        static DateTime _last_save = DateTime.Now;

        public static void NewFile()
        {//new file is created because filename changed
            SaveToFile();
            lock (_locker)
            {

                _filename = DIR_LOG_FILES + @"Log." + DateTime.Now.ToString("yyMMdd.HHmm") + @".txt";
                _counter = 0;
            }
        }
        public static void Log(string LogMessage, int Importance)
        {
            if (Importance < MIN_IMPORTANCE) return;
            lock (_locker)
            {
                _list_log.Add(String.Format("{0:HH:mm:ss.ffff},{1},{2}", DateTime.Now, LogMessage, Importance));
                _counter++;
            }
            TimeSpan timeDiff = DateTime.Now - _last_save;

            if (_counter > SAVE_COUNTER || timeDiff.TotalMilliseconds > SAVE_PERIOD)
                SaveToFile();
        }

        public static void SaveToFile()
        {
            lock (_locker)
                if (_list_log.Count == 0)
                {
                    _last_save = _last_save = DateTime.Now;
                    return;
                }
            lock (_locker)
            {
                using (StreamWriter logfile = File.AppendText(_filename))
                {

                    foreach (string s in _list_log) logfile.WriteLine(s);
                    logfile.Flush();
                    logfile.Close();
                }

                _list_log.Clear();
                _counter = 0;
                _last_save = DateTime.Now;
            }
        }


        public static void ReadLog(string logfile)
        {
            using (StreamReader r = File.OpenText(logfile))
            {
                string line;
                while ((line = r.ReadLine()) != null)
                {
                    Console.WriteLine(line);
                }
                r.Close();
            }
        }
    }
}

Answer 11

我没有使用外部库 log4net，而是创建了自己的简单类，高度可定制且易于使用（使用YOURNAMESPACEHERE您需要的命名空间进行编辑）。

控制台应用程序

using System;
using System.IO;

namespace YOURNAMESPACEHERE
{
    enum LogEvent
    {
        Info = 0,
        Success = 1,
        Warning = 2,
        Error = 3
    }

    internal static class Log
    {
        private static readonly string LogSession = DateTime.Now.ToLocalTime().ToString("ddMMyyyy_HHmmss");
        private static readonly string LogPath = AppDomain.CurrentDomain.BaseDirectory + "logs";

        internal static void Write(LogEvent Level, string Message, bool ShowConsole = true, bool WritelogFile = true)
        {
            string Event = string.Empty;
            ConsoleColor ColorEvent = Console.ForegroundColor;

            switch (Level)
            {
                case LogEvent.Info:
                    Event = "INFO";
                    ColorEvent = ConsoleColor.White;
                    break;
                case LogEvent.Success:
                    Event = "SUCCESS";
                    ColorEvent = ConsoleColor.Green;
                    break;
                case LogEvent.Warning:
                    Event = "WARNING";
                    ColorEvent = ConsoleColor.Yellow;
                    break;
                case LogEvent.Error:
                    Event = "ERROR";
                    ColorEvent = ConsoleColor.Red;
                    break;
            }

            if (ShowConsole)
            {
                Console.ForegroundColor = ColorEvent;
                Console.WriteLine(" [{0}] => {1}", DateTime.Now.ToString("HH:mm:ss"), Message);
                Console.ResetColor();
            }

            if (WritelogFile)
            {
                if (!Directory.Exists(LogPath))
                    Directory.CreateDirectory(LogPath);

                File.AppendAllText(LogPath + @"\" + LogSession + ".log", string.Format("[{0}] => {1}: {2}\n", DateTime.Now.ToString("HH:mm:ss"), Event, Message));
            }
        }
    }
}

没有控制台应用程序（只有日志）

using System;
using System.IO;

namespace YOURNAMESPACEHERE
{
    enum LogEvent
    {
        Info = 0,
        Success = 1,
        Warning = 2,
        Error = 3
    }

internal static class Log
{
    private static readonly string LogSession = DateTime.Now.ToLocalTime().ToString("ddMMyyyy_HHmmss");
    private static readonly string LogPath = AppDomain.CurrentDomain.BaseDirectory + "logs";

    internal static void Write(LogEvent Level, string Message)
    {
        string Event = string.Empty;

        switch (Level)
        {
            case LogEvent.Info:
                Event = "INFO";
                break;
            case LogEvent.Success:
                Event = "SUCCESS";
                break;
            case LogEvent.Warning:
                Event = "WARNING";
                break;
            case LogEvent.Error:
                Event = "ERROR";
                break;
        }

        if (!Directory.Exists(LogPath))
            Directory.CreateDirectory(LogPath);

        File.AppendAllText(LogPath + @"\" + LogSession + ".log", string.Format("[{0}] => {1}: {2}\n", DateTime.Now.ToString("HH:mm:ss"), Event, Message));
    }
}

用法：

控制台应用程序

Log.Write(LogEvent.Info, "Test message"); // It will print an info in your console, also will save a copy of this print in a .log file.
Log.Write(LogEvent.Warning, "Test message", false); // It will save the print as warning only in your .log file.
Log.Write(LogEvent.Error, "Test message", true, false); // It will print an error only in your console.

没有控制台应用程序（只有日志）

Log.Write(LogEvent.Info, "Test message"); // It will print an info in your .log file.

Answer 12

我发现GitHub上heiswayi的SimpleLogger很好。