How to Make a Log File Using ASP.NET C#

The performance of our applications, as well as errors and bugs, must always be tracked in an application development environment. We always keep a log of any errors and defects in a temporary folder. Therefore, today’s topic will be how to write a log in a.Net application. The main source of data for network observability is a log file, which is a computer-generated data file containing details about usage patterns, activities, and processes within an operating system, application, server, or other device.

I will therefore explain how to write the log using the C# programming language in this blog.

Lets proceed and create the Log file.

Step 1 :
Gets or sets the file directory path to the location of the file where the events are stored for the log.

<appSettings>
 <!-- Log File-->  
 <add key="LogFile" value="D:\Temp\log" /> 
 <add key="Logdays" value="5" />                                                   //Store the number of days after which you want to delete the logs.
 </appSettings>          

Step 2:
We shall determine whether the Log file is there or not using the StringBuilder . If one doesn’t already exist, we’ll make one and add the text to the Log file.

private string LogPath;
private int Logdays = 0;
public void Write(Exception ex)
{
 LogPath = System.Configuration.ConfigurationManager.AppSettings["LogFile"];
 Logdays = Convert.ToInt16(System.Configuration.ConfigurationManager.AppSettings["Logdays"]);
 WriteLog(LogPath, ex.Message, ex.StackTrace);
 }

public void WriteLog(string exceptionSource, string message, string stackTrace)
 {
 LogPath = System.Configuration.ConfigurationManager.AppSettings["LogFile"];
 Logdays = Convert.ToInt16(System.Configuration.ConfigurationManager.AppSettings["Logdays"]);
 exceptionSource = LogPath;
 WriteText(exceptionSource, message, stackTrace);
 }

Step 3 :
The Log file can be formatted according to our specifications for what and how to write.

public void WriteText(string exceptionSource, string message, string stackTrace)
       {
               _logFile = _getLogFile();
               StringBuilder sb = new StringBuilder();
               sb.AppendLine("------------------");
               sb.Append(DateTime.Now.ToString());
               sb.Append("------------------");
               sb.AppendLine(eventLogType.ToString());
               if (!string.IsNullOrEmpty(exceptionSource))
               {
                   sb.AppendLine(exceptionSource);
               }
               if (!string.IsNullOrEmpty(message))
               {
                   sb.AppendLine(message);
               }
               if (!string.IsNullOrEmpty(stackTrace))
               {
                   sb.AppendLine(stackTrace);
               }
               File.AppendAllText(_logFile + ".txt", sb.ToString());
       }
         
 private string _getLogFile()                                                                                        //Create syncLog folder if not exists
       {
               if (!Directory.Exists(LogPath))
              {
               Directory.CreateDirectory(LogPath);

       }
              string filePath;
              filePath = LogPath + @"Log_" + DateTime.Now.Year + "_" + DateTime.Now.Month + "_" + DateTime.Now.Day;
              return filePath;
       }

Step 4 :
To generate the Log file, let’s now invoke the WriteLog() function.

protected void Page_Load(object sender, EventArgs e)
{
string LogPath = System.Configuration.ConfigurationManager.AppSettings["LogFile"];
int Logdays = Convert.ToInt16(System.Configuration.ConfigurationManager.AppSettings["Logdays"]);
WriteLog(LogPath, "Getting the info", "");
}