how to create log file in c# asp.net

Hi friends, in this post we will discuss how to create log file in c# asp.netor you can say how to create error log text file in c#, How to create log file to record errors and exceptions in asp.net. Creating a error log file to log all errors and exceptions occurs on our website in a text file is a good idea. It tells developers on which page we have errors so we find it easily and resolve this.

To add log file on a already built website or a new website you just have to follow a few simple steps:

1. Open your website or create a new website.

2. Now Right Click on Application name in Solution Explorer and Go to Add > Add New Item.

3. New pop up window will open, Now Choose Global Application Class and click on Add. If you have already a Global Application Class in your website then skip to next step.

4. Open Global Application Class and following code on Application_Error Event.

void Application_Error(object sender, EventArgs e) 
    {
        Exception ex = new Exception();
        ex = Server.GetLastError().GetBaseException();

        System.IO.FileStream fs = new System.IO.FileStream(Server.MapPath("~/Errors_Folder/ErrorLOG.txt"), System.IO.FileMode.OpenOrCreate, System.IO.FileAccess.ReadWrite);
        System.IO.StreamWriter s = new System.IO.StreamWriter(fs);
        s.BaseStream.Seek(0, System.IO.SeekOrigin.End);
        s.WriteLine("ERROR DATE: " + System.DateTime.Now.ToString(System.Globalization.CultureInfo.InvariantCulture) + " \nERROR MESSAGE: " + ex.Message + "\nSOURCE: " + ex.Source + "\nFORM NAME: " + System.Web.HttpContext.Current.Request.Url.ToString() + "\nQUERYSTRING: " + Request.QueryString.ToString() + "\nTARGETSITE: " + ex.TargetSite.ToString() + "\nSTACKTRACE: " + ex.StackTrace + System.Diagnostics.EventLogEntryType.Error);
        s.WriteLine("-------------------------------------------------------------------------------------------------------------");
        s.Close();

    }

5. For this to work you need read/write permission on folder, in which our Log File reside.

And we are done, so whenever any error occurs on our website it will automatically logged in our log file.