public void LogFile(string sExceptionName, string sEventName, string sControlName, int       nErrorLineNo, string sFormName)
        {
            StreamWriter log;
            if (!File.Exists("logfile.txt"))
            {
                log = new StreamWriter("logfile.txt");
            }
            else
            {
                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:
            log.Close();
        }
    }

Note

·   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.

·   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;
            try
            {
                linenum = Convert.ToInt32(e.StackTrace.Substring(e.StackTrace.LastIndexOf(":line") + 5));
            }
            catch
            {
                //Stack trace is not available!
            }
            return linenum;
        }
    }

Step 3:Now put your line of code within try and catch blog and call LogFile

method as below

try
            {
                //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.

Event Name:System.Windows.Forms.MouseEventArgs

Control Name:btnUpdate

Error Line No.:106