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:
   
   1. using System;  
   2. using System.Collections.Generic;  
   3. using System.Linq;  
   4. using System.Text;  
   5. using System.Diagnostics;  
   6. using System.IO;  
   7. using System.Security.Permissions;  
   8.   
   9. namespace Common {  
   10.     /*This Class is used for logging messages to either a custom EventViewer or in a plain text file located on web server.*/  
   11.   
   12.     public class Logging {#region "Variables"  
   13.   
   14.         private string sLogFormat;  
   15.         private string sErrorTime;  
   16.  
   17.         #endregion  
   18.  
   19.  
   20.         #region "Local methods"  
   21.   
   22.         /* Write to Txt Log File*/  
   23.         public void WriteToLogFile(string sErrMsg) {  
   24.             try {  
   25.                 //sLogFormat used to create log format :  
   26.                 // dd/mm/yyyy hh:mm:ss AM/PM ==> Log Message  
   27.                 sLogFormat = DateTime.Now.ToShortDateString().ToString() + " " + DateTime.Now.ToLongTimeString().ToString() + " ==> ";  
   28.   
   29.                 //this variable used to create log filename format "  
   30.                 //for example filename : ErrorLogYYYYMMDD  
   31.                 string sYear = DateTime.Now.Year.ToString();  
   32.                 string sMonth = DateTime.Now.Month.ToString();  
   33.                 string sDay = DateTime.Now.Day.ToString();  
   34.                 sErrorTime = sYear + sMonth + sDay;  
   35.   
   36.                 //writing to log file  
   37.                 string sPathName = "C:\\Logs\\ErrorLog" + sErrorTime;  
   38.                 StreamWriter sw = new StreamWriter(sPathName + ".txt", true);  
   39.                 sw.WriteLine(sLogFormat + sErrMsg);  
   40.                 sw.Flush();  
   41.                 sw.Close();  
   42.             } catch (Exception ex) {  
   43.                 WriteToEventLog("MySite", "Logging.WriteToLogFile", "Error: " + ex.ToString(), EventLogEntryType.Error);  
   44.             }  
   45.         }  
   Write to Event Log
   
   1. public void WriteToEventLog(string sLog, string sSource, string message, EventLogEntryType level) {  
   2.     //RegistryPermission regPermission = new RegistryPermission(PermissionState.Unrestricted);  
   3.     //regPermission.Assert();  
   4.   
   5.     if (!EventLog.SourceExists(sSource)) EventLog.CreateEventSource(sSource, sLog);  
   6.   
   7.     EventLog.WriteEntry(sSource, message, level);  
   8. }  
   9.  
   10. #endregion  
   11. }  
   12. }  
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!!!