csharp: datagridview Convert csv file

 /// <summary>        /// 保存文件        /// 涂聚文        /// 2014-08-29        /// Geovin Du        /// </summary>        /// <param name="dGV"></param>        /// <param name="filename"></param>        public static void DataGridViewToCsV(DataGridView dGV, string filename)        {            string stOutput = "";            // Export titles:              string sHeaders = "";            for (int j = 0; j < dGV.Columns.Count; j++)                sHeaders = sHeaders.ToString() + Convert.ToString(dGV.Columns[j].HeaderText) + ", ";            stOutput += sHeaders + "/r/n";            // Export data.              for (int i = 0; i < dGV.RowCount - 1; i++)            {                string stLine = "";                for (int j = 0; j < dGV.Rows[i].Cells.Count; j++)                    stLine = stLine.ToString() + Convert.ToString(dGV.Rows[i].Cells[j].Value) + ", ";                stOutput += stLine + "/r/n";            }            UTF8Encoding utf8 = new UTF8Encoding();            string file = "1.csv";            SaveFileDialog saveFileDialog1 = new SaveFileDialog();            saveFileDialog1.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Desktop);//Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);            saveFileDialog1.CreatePRompt = true;            saveFileDialog1.OverwritePrompt = true;            saveFileDialog1.Title = "Save text Files";            //saveFileDialog1.CheckFileExists = true;            //saveFileDialog1.CheckPathExists = true;            saveFileDialog1.DefaultExt = "csv";            saveFileDialog1.Filter = "csv files (*.csv)|*.csv|All files (*.*)|*.*";            saveFileDialog1.FilterIndex = 1;            saveFileDialog1.RestoreDirectory = true;            System.IO.Stream fileStream;            if (saveFileDialog1.ShowDialog() == DialogResult.OK)            {                //FileStream fs = new FileStream(filename, FileMode.Create);                file = saveFileDialog1.FileName;                fileStream = saveFileDialog1.OpenFile();                MemoryStream userInput = new MemoryStream();                byte[] output = Encoding.Default.GetBytes(stOutput);                //fileStream.Read(output, 0, (int)output.Length);                fileStream.Write(output, 0, output.Length);                fileStream.Close();            }         }        /// <summary>        /// 保存文件        /// 涂聚文        /// 2014-08-28        /// Geovin Du        /// </summary>        /// <param name="dGV"></param>        /// <param name="filename"></param>        public static void DataGridViewToCsVDu(DataGridView dGV, string filename)        {            string stOutput = "";            // Export titles:              string sHeaders = "";            for (int j = 0; j < dGV.Columns.Count; j++)                sHeaders = sHeaders.ToString() + Convert.ToString(dGV.Columns[j].HeaderText) + ", ";            stOutput += sHeaders + "/r/n";            // Export data.              for (int i = 0; i < dGV.RowCount - 1; i++)            {                string stLine = "";                for (int j = 0; j < dGV.Rows[i].Cells.Count; j++)                    stLine = stLine.ToString() + Convert.ToString(dGV.Rows[i].Cells[j].Value) + ", ";                stOutput += stLine + "/r/n";            }            UTF8Encoding utf8 = new UTF8Encoding();            //Encoding utf16 = Encoding.GetEncoding(1200);//unicode encoding            byte[] output = Encoding.Default.GetBytes(stOutput);            FileStream fs = new FileStream(filename, FileMode.Create);            BinaryWriter bw = new BinaryWriter(fs, Encoding.Default);            bw.Write(output, 0, output.Length); //write the encoded file            bw.Flush();            bw.Close();            fs.Close();                    }