public static void ExportResultLog(System.Data.DataTable dt, string fileName, string path)

        {

            if (!System.IO.Directory.Exists(path))

            {

                System.IO.Directory.CreateDirectory(path);

            }

            string strPath = path + fileName;

            StringBuilder strColu = new StringBuilder();

            StringBuilder strLineValue = new StringBuilder();

            try

            {

                if (System.IO.File.Exists(strPath))

                {

                    string[] stringlines = System.IO.File.ReadAllLines(strPath, Encoding.Default);

                    string line = string.Empty;

                    foreach (string readLine in stringlines)

                    {

                        line += readLine + "\r\n";

                    }

                    line = line.Remove(line.Length - 2, 2);

                    System.IO.StreamWriter sw = new System.IO.StreamWriter(strPath, false, Encoding.GetEncoding("UTF-8"));

                    sw.WriteLine(line);

                    foreach (DataRow dr in dt.Rows)

                    {

                        strLineValue.Remove(0, strLineValue.Length);

                        for (int i = 0; i <= dt.Columns.Count - 1; i++)

                        {

                            strLineValue.Append(ReplaceChar(dr[i] == DBNull.Value ? "" : dr[i].ToString()));

                            strLineValue.Append(",");

                        }

                        strLineValue.Remove(strLineValue.Length - 1, 1);

                        sw.WriteLine(strLineValue.ToString());

                    }

                    sw.Close();

                }

                else

                {

                    System.IO.StreamWriter sw = new System.IO.StreamWriter(strPath, false, Encoding.GetEncoding("UTF-8"));

                    for (int i = 0; i <= dt.Columns.Count - 1; i++)

                    {

                        strColu.Append(dt.Columns[i].ColumnName);

                        strColu.Append(",");

                    }

                    strColu.Remove(strColu.Length - 1, 1);

                    sw.WriteLine(strColu);

                    foreach (DataRow dr in dt.Rows)

                    {

                        strLineValue.Remove(0, strLineValue.Length);

                        for (int i = 0; i <= dt.Columns.Count - 1; i++)

                        {

                            strLineValue.Append(ReplaceChar(dr[i] == DBNull.Value ? "" : dr[i].ToString()));

                            strLineValue.Append(",");

                        }

                        strLineValue.Remove(strLineValue.Length - 1, 1);

                        sw.WriteLine(strLineValue.ToString());

                    }

                    sw.Close();

                }

            }

            catch (Exception ex)

            {

                throw ex;

            }

        }

        public static void ExportLog(System.Data.DataTable dtLogInfo, string fileName, string path)

        {

            string strPath = System.IO.Path.Combine(AppDomain.CurrentDomain.BaseDirectory, path);

            if (!System.IO.Directory.Exists(strPath))

            {

                System.IO.Directory.CreateDirectory(strPath);

            }

            strPath = path + fileName;

            StringBuilder strColu = new StringBuilder();

            StringBuilder strValue = new StringBuilder();

            try

            {

                if (System.IO.File.Exists(strPath))

                {

                    string[] stringlines = System.IO.File.ReadAllLines(strPath, Encoding.Default);

                    string line = string.Empty;

                    foreach (string readLine in stringlines)

                    {

                        line += readLine + "\r\n";

                    }

                    System.IO.StreamWriter sw = new System.IO.StreamWriter(strPath, false, Encoding.GetEncoding("UTF-8"));

                    strValue.Remove(0, strValue.Length);

                    for (int i = 0; i <= dtLogInfo.Columns.Count - 1; i++)

                    {

                        strValue.Append(ReplaceChar(dtLogInfo.Rows[0][i] == DBNull.Value ? "" : dtLogInfo.Rows[0][i].ToString()));

                        strValue.Append(",");

                    }

                    strValue.Remove(strValue.Length - 1, 1);

                    string value = line + strValue.ToString();

                    sw.WriteLine(value);

                    sw.Close();

                }

                else

                {

                    System.IO.StreamWriter sw = new System.IO.StreamWriter(strPath, false, Encoding.GetEncoding("UTF-8"));

                    for (int i = 0; i <= dtLogInfo.Columns.Count - 1; i++)

                    {

                        strColu.Append(dtLogInfo.Columns[i].ColumnName);

                        strColu.Append(",");

                    }

                    strColu.Remove(strColu.Length - 1, 1);

                    sw.WriteLine(strColu);

                    strValue.Remove(0, strValue.Length);

                    for (int i = 0; i <= dtLogInfo.Columns.Count - 1; i++)

                    {

                        strValue.Append(ReplaceChar(dtLogInfo.Rows[0][i] == DBNull.Value ? "" : dtLogInfo.Rows[0][i].ToString()));

                        strValue.Append(",");

                    }

                    strValue.Remove(strValue.Length - 1, 1);

                    sw.WriteLine(strValue.ToString());

                    sw.Close();

                }

            }

            catch (Exception ex)

            {

                throw ex;

            }

        }