Logging To Event Viewer Or Log File Using C# .NET

In many of our .NET projects, we need to log exceptions/errors/information in either Windows event log or a custom text Log file for debugging/review/reporting purposes. Here is a generic class written for logging, you can use this class to any of your C# .NET projects and use WriteToLogFile OR WriteToEventLog methods wherever required in you code.

1. To achieve this, add ‘Common’ folder or project in your visual studio solution.
   
   Add a class file named ‘Logging’ and use the following code. Make sure to add all the required reference assemblies.
   
   Code:
   

   using System;
   using System.Collections.Generic;
   using System.Linq;
   using System.Text;
   using System.Diagnostics;
   using System.IO;
   using System.Security.Permissions;
   
   namespace Common {
       /*This Class is used for logging messages to either a custom EventViewer or in a plain text file located on web server.*/
   
       public class Logging {#region "Variables"
   
           private string sLogFormat;
           private string sErrorTime;
   
           #endregion
   
   
           #region "Local methods"
   
           /* Write to Txt Log File*/
           public void WriteToLogFile(string sErrMsg) {
               try {
                   //sLogFormat used to create log format :
                   // dd/mm/yyyy hh:mm:ss AM/PM ==> Log Message
                   sLogFormat = DateTime.Now.ToShortDateString().ToString() + " " + DateTime.Now.ToLongTimeString().ToString() + " ==> ";
   
                   //this variable used to create log filename format "
                   //for example filename : ErrorLogYYYYMMDD
                   string sYear = DateTime.Now.Year.ToString();
                   string sMonth = DateTime.Now.Month.ToString();
                   string sDay = DateTime.Now.Day.ToString();
                   sErrorTime = sYear + sMonth + sDay;
   
                   //writing to log file
                   string sPathName = "C:\\Logs\\ErrorLog" + sErrorTime;
                   StreamWriter sw = new StreamWriter(sPathName + ".txt", true);
                   sw.WriteLine(sLogFormat + sErrMsg);
                   sw.Flush();
                   sw.Close();
               } catch (Exception ex) {
                   WriteToEventLog("MySite", "Logging.WriteToLogFile", "Error: " + ex.ToString(), EventLogEntryType.Error);
               }
           }

   Write to Event Log
   

   public void WriteToEventLog(string sLog, string sSource, string message, EventLogEntryType level) {
       //RegistryPermission regPermission = new RegistryPermission(PermissionState.Unrestricted);
       //regPermission.Assert();
   
       if (!EventLog.SourceExists(sSource)) EventLog.CreateEventSource(sSource, sLog);
   
       EventLog.WriteEntry(sSource, message, level);
   }
   
   #endregion
   }
   }

2. Call WriteToLogFile AND/OR WriteToEventLog with appropriate parameters in other functions as required.
   
   
3. Build & deploy the solution. Check Windows’ event viewer or custom Log file to see if it’s working.
   
   Happy Coding!!!