.NET拾忆：EventLog（Windows事件日志监控）

操作Windows日志：EventLog

1：事件日志名（logName）：“事件查看器”中的每一项，如“应用程序”、“Internet Explorer”、“安全性”和“系统”都是日志（严格地说是日志的显示名字）

2：事件源：列表中的“来源”，创建时和事件日志相关联；

3：事件类型：包括“信息”、“错误”等；

基本操作：

1：创建日志：我没找到直接创建日志的方法，日志应该都是通过下面的创建事件源来间接创建；

2：创建事件源：静态方法EventLog.CreateEventSource(string sourceName, string LogName); //参数分别表示事件源名和日志名

功能说明：在某个事件日志中创建事件源，如果事件日志不存在，则自动创建；

3：删除日志：静态方法EventLog.Delete(string logName);

4：删除事件源：静态方法EventLog.DeleteEventSource(string sourceName);

5：判断日志是否存在：静态方法EventLog.Exists(string logName);

6：判断事件源是否存在：静态方法EventLog. SourceExists (string sourceName);

7：写日志：使用EventLog类的实例调用方法WriteEntry(string logDesc, EventLogEntryType.Information); //或者EventLogEntryType.Error

测试

using System;
using System.Diagnostics;

namespace WindowsConsoleApp
{
    //测试
    public class EnventLogHelper
    {
        private EventLog log;

        public EnventLogHelper()
        {
            log = new EventLog();//默认写应用程序日志
        }
        public EnventLogHelper(string name)
        {
            log = new EventLog(name);//指定写入的分类，用户自定义则新建分组。系统保留//"Application"应用程序, "Security"安全, "System"系统
            //或者可以用 log.Log = "Security";指定
        }

        public void WriteToApp()
        {
            try
            {

                log.Source = "我的应用程序";//日志来源
                log.WriteEntry("处理信息1", EventLogEntryType.Information);//日志类型
                log.WriteEntry("处理信息2", EventLogEntryType.Information);
                throw new System.IO.FileNotFoundException("readme.txt文件未找到");
            }
            catch (System.IO.FileNotFoundException exception)
            {
                log.WriteEntry(exception.Message, EventLogEntryType.Error);

            }
        }

        public void ReadLog()
        {
            EventLogEntryCollection eventLogEntryCollection = log.Entries;//获取日志collection
            foreach (EventLogEntry entry in eventLogEntryCollection)
            {

                string info = string.Empty;

                info += "【类型】：" + entry.EntryType.ToString() + ";";
                info += "【日期】" + entry.TimeGenerated.ToLongDateString() + ";";
                info += "【时间】" + entry.TimeGenerated.ToLongTimeString() + ";";

                info += "【计算机】" + entry.MachineName + "【来源】" + entry.Source + "【详细信息】" + entry.Message + "【】";
                //
                Console.WriteLine(info);

            }
        }

    }
}

查询Windows日志：EventLogQuery与EventRecord

监控Windows日志增量变化：EventLogWatcher

using System;
using System.Diagnostics.Eventing.Reader;

namespace WindowsConsoleApp
{
    class SubscribeToEventsExample
    {
        static void Main1(string[] args)
        {
            //监控类
            EventLogWatcher watcher = null;

            try
            {
                // Xpath语法筛选目标事件的发生
                EventLogQuery subscriptionQuery = new EventLogQuery(
                "Application", PathType.LogName, "*[System/Level=2] or *[System/Level=3]");

                watcher = new EventLogWatcher(subscriptionQuery);

                // 订阅到事件发生时候，触发事件
                watcher.EventRecordWritten +=
                    new EventHandler<EventRecordWrittenEventArgs>(
                        EventLogEventRead);

                //开始订阅Windows日志
                watcher.Enabled = true;

                //如果不停止，监控类会不停查询时间发生，直到Enable设置为false
                for (int i = ; i < ; i++)
                {
                    // Wait for events to occur.
                    System.Threading.Thread.Sleep();
                }

            }
            catch (EventLogReadingException e)
            {
                Console.WriteLine("Error reading the log: {0}", e.Message);
            }
            finally
            {
                // 停止监控
                watcher.Enabled = false;

                if (watcher != null)
                {
                    watcher.Dispose();
                }
            }
        }

        /// <summary>
        /// 事件触发
        /// </summary>
        public static void EventLogEventRead(object obj, EventRecordWrittenEventArgs arg)
        {
            // Make sure there was no error reading the event.
            if (arg.EventRecord != null)
            {
                Console.WriteLine("Received event {0} from the subscription.",
                    arg.EventRecord.Id);
                Console.WriteLine("Description: {0}", arg.EventRecord.FormatDescription());

                //log.EventId = arg.EventRecord.Id;//系统日志分配的记录ID
                //log.Source = arg.EventRecord.ProviderName;//来源
                //log.Level = (int)(arg.EventRecord.LevelDisplayName == "错误" ? WinLogLevelID.ERROR : WinLogLevelID.WARN);
                //log.TaskName = arg.EventRecord.TaskDisplayName ?? "无";
                //log.LogMessage = arg.EventRecord.FormatDescription();
                //log.TimeCreate = arg.EventRecord.TimeCreated ?? DateTime.Now;
            }
            else
            {
                Console.WriteLine("The event instance was null.");
            }
        }
    }
}

监控订阅：https://msdn.microsoft.com/en-us/library/bb671202(v=vs.90).aspx

查询规则： https://msdn.microsoft.com/en-us/library/bb399427.aspx

资源：

源码：https://referencesource.microsoft.com/#System/services/monitoring/system/diagnosticts/EventLog.cs

EventLog:https://msdn.microsoft.com/zh-cn/library/system.diagnostics.eventlog(v=vs.110).aspx

EventQuery:

https://msdn.microsoft.com/en-us/library/bb671200.aspx

EventLogReader:

https://msdn.microsoft.com/zh-cn/library/system.diagnostics.eventing.reader.eventlogreader(v=vs.110).aspx