public void ExportTxt()
        {
            var file = System.IO.File.Open(path, System.IO.FileMode.Open);
            using (var stream = new System.IO.StreamReader(file))
            {
                while (!stream.EndOfStream)
                {
                    string[] qwe = stream.ReadLine().Split(‘,‘);
                    string sql = string.Format("insert into 表 values(‘{0}‘,‘{1}‘,‘{2}‘,‘{3}‘,‘{4}‘,‘{5}‘,‘{6}‘,‘{7}‘)",
                    qwe[0],
                    qwe[1],
                    qwe[2],
                    qwe[3],
                    qwe[4],
                    qwe[5],
                    qwe[6],
                    qwe[7]);
                }
            }

           
            file.Close();
        }

public void WriteTxt()
        {
            System.IO.FileStream fs = new System.IO.FileStream(path, System.IO.FileMode.Create);
            //获得字节数组
            System.Data.DataTable dt = handle.ExecuteDataSet("select * from 表").Tables[0];

            for (int i = 0; i < dt.Rows.Count; i++)
            {
                for (int x = 0; x < dt.Columns.Count; x++)
                {
                    byte[] wr;
                    if (x != dt.Columns.Count - 1)
                    {
                        wr =  new UTF8Encoding(true).GetBytes(dt.Rows[i][x].ToString() + ",");
                        
                        
                    }
                    else
                    {
                        wr = new UTF8Encoding(true).GetBytes(dt.Rows[i][x].ToString() + "\r\n");
                        
                    }

//字节数组,字节偏移量,最多写入的字节数

fs.Write(wr, 0, wr.Length); } } //清空缓冲区、关闭流  fs.Flush(); fs.Close(); }