In this blog I have described how to create log file in C#. Log file can be simple text file, XML document or we can also use tables in database to create log. Here I have used .txt file. In this file we have stored information about generated exception of application. Using this log file we have easily find out error list. In this file we have stored information according our requirement. For example in log file we have stored file name, exception name, date and time, error line number, event name, Controls name etc.
public void LogFile(string sExceptionName, string sEventName, string sControlName, int nErrorLineNo, string sFormName)
log = new StreamWriter("logfile.txt");
log = File.AppendText("logfile.txt");
// Write to the file:
log.WriteLine("Data Time:" + DateTime.Now);
log.WriteLine("Exception Name:" + sExceptionName);
log.WriteLine("Event Name:" + sEventName);
log.WriteLine("Control Name:" + sControlName);
log.WriteLine("Error Line No.:" + nErrorLineNo);
log.WriteLine("Form Name:" + sFormName);
// Close the stream:
· Include System.IO namespace.
· LogFile method call by catch section when any exception is triggered.
· LogFile method takes five arguments that used to write within
· logfile.txt is file that stored in your application bin/debug folder.
Step 2: Write below ExceptionHelper class (line of code) that return
occurred error line number.
public static class ExceptionHelper
public static int LineNumber(this Exception e)
int linenum = 0;
linenum = Convert.ToInt32(e.StackTrace.Substring(e.StackTrace.LastIndexOf(":line") + 5));
//Stack trace is not available!
Step 3: Now put your line of code within try and catch blog and call LogFile
method as below
//put here your code
catch (Exception exe)
//call LogFile method and pass argument as Exception message, event name, control name, error line number, current form name
LogFile(exe.Message, e.ToString(), ((Control)sender).Name, exe.LineNumber(), this.FindForm().Name);
Step 4: If any exception is generated then LogFile.txt look like as below
Data Time:3/6/2013 4:29:47 PM
Exception Name:Input string was not in a correct format.Couldn't store
<LineNumber> in salary Column. Expected type is Double.
Error Line No.:106