using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;
namespace ConsoleApp
{
 /// <summary>
 /// 系统日志
 /// </summary>
 public class PackSystemEventLog
 {
  /// <summary>
  /// 错误信息
  /// </summary>
  private static string ErrorInfo { get; set; }
  /// <summary>
  /// 创建系统事件日志分类
  /// </summary>
  /// <param name="eventSourceName">注册事件源(比如说这个日志来源于某一个应用程序)</param>
  /// <param name="logName">日志名称(事件列表显示的名称)</param>
  /// <returns></returns>
  public static bool CreateSystemEventLogCategory(string eventSourceName, string logName)
  {
   bool createResult = false;
   try
   {
    if (!EventLog.SourceExists(eventSourceName))
    {
     EventLog.CreateEventSource(eventSourceName, logName);
    }
    createResult = true;
   }
   catch (Exception ex)
   {
    createResult = false;
    ErrorInfo = ex.Message;
   }
   return createResult;
  }
  /// <summary>
  /// 删除系统事件日志分类
  /// </summary>
  /// <param name="eventSource">EventName事件源</param>
  /// <returns></returns>
  public static bool RemoveSystemEventSourceCategory(string eventSource)
  {
   bool createResult = false;
   try
   {
    if (EventLog.SourceExists(eventSource))
    {
     EventLog.DeleteEventSource(eventSource, ".");
    }
    createResult = true;
   }
   catch (Exception ex)
   {
    createResult = false;
    ErrorInfo = ex.Message;
   }
   return createResult;
  }
  /// <summary>
  /// 向系统日志中写入日志
  /// </summary>
  /// <param name="eventSource">事件源</param>
  /// <param name="msg">写入日志信息</param>
  /// <param name="type">日志文本分类(警告、信息、错误)</param>
  /// <returns></returns>
  public static bool WriteSystemEventLog(string eventSource, string msg, EventLogEntryType type)
  {
   bool writeResult = false;
   try
   {
    if (!EventLog.SourceExists(eventSource))
    {
     writeResult = false;
     ErrorInfo = "日志分类不存在!";     
    }
    else
    {
     EventLog.WriteEntry(eventSource, msg, type);
     writeResult = true;
    }
   }
   catch (Exception ex)
   {
    writeResult = false;
    ErrorInfo = ex.Message;
   }
   return writeResult;
  }
  /// <summary>
  /// 删除事件源中logName(好像删除了所有的该分类的日志)
  /// </summary>
  /// <param name="eventSource"></param>
  /// <param name="logName"></param>
  /// <returns></returns>
  public static bool RemoveSystemEventLog(string eventSource, string logName)
  {
   bool removeResult = false;
   try
   {
    if (!EventLog.SourceExists(eventSource))
    {
     removeResult = false;
     ErrorInfo = "日志分类不存在!";
    }
    else
    {
     EventLog.Delete(logName);
     removeResult = true;
    }
   }
   catch (Exception ex)
   {
    removeResult = false;
    ErrorInfo = ex.Message;
   }
   return removeResult;
  }
  /// <summary>
  /// 获取错误信息
  /// </summary>
  /// <returns></returns>
  public static string GetErrorMessage()
  {
   return ErrorInfo;
  }
 }
}