Write exception log in asp.net c#

// Method

private static String ErrorlineNo, Errormsg, extype, exurl, hostIp, ErrorLocation, HostAdd;

public static void Write_Logs(Exception ex)

    {

        var line = Environment.NewLine + Environment.NewLine;

        ErrorlineNo = ex.StackTrace.Substring(ex.StackTrace.Length - 7, 7);

        Errormsg = ex.GetType().Name.ToString();

        extype = ex.GetType().ToString();

        exurl = context.Current.Request.Url.ToString();

        ErrorLocation = ex.Message.ToString();

        try

        {

            string filepath = context.Current.Server.MapPath("~/Ex_Log/");  //Text File Path

            if (!Directory.Exists(filepath))

            {

                Directory.CreateDirectory(filepath);

            }

            filepath = filepath + DateTime.Today.ToString("dd-MM-yy") + ".txt";   //Text File Name

            if (!File.Exists(filepath))

            {

                File.Create(filepath).Dispose();

            }

            using (StreamWriter sw = File.AppendText(filepath))

            {

                sw.WriteLine(line);

                string error = "Date:" + " " + DateTime.Now.ToString() + "," + "LineNo :" + " " + ErrorlineNo + "," + "Message:" + " " + Errormsg + "," + "ExceptionType:" + " " + extype + "," + "Location :" + " " + ErrorLocation + "," + "PageUrl:" + " " + exurl + "," + "HostIP:" + " " + hostIp;

                sw.Flush();

                sw.Close();

            }

        }

        catch (Exception e)

        {

            e.ToString();

        }

    }

//Call

    protected void btn_backCatalogue_Click(object sender, EventArgs e)

    {

        try

        {

        }

        catch (Exception ex)

        {

            Write_Logs(ex);

        }

    }