将List中部分字段转换为DataTable中

由于原来方法导出数据量比较大 的时候，出现卡顿现象：搜索简单改造：（下面方法借助NPIO）


  /// <summary>

        /// 将List中原文和译文转换为Datatable

        /// </summary>

        /// <typeparam name="MemoryFields">术语</typeparam>

        /// <param name="list">术语列宁表</param>

        /// <returns>只包含原文和译文的DataTable</returns>

        public System.Data.DataTable list2Datatable<MemoryFields>(List<MemoryFields> list)

        {

            PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(typeof(MemoryFields));

            System.Data.DataTable dt = new System.Data.DataTable();

            //for (int i = 0; i < properties.Count; i++)

            //{

            PropertyDescriptor propertyOrig = properties["Orig"];//Orig为字段

            dt.Columns.Add("原文", propertyOrig.PropertyType);

            PropertyDescriptor propertyTran = properties["Tran"]; //Tran为字段

            dt.Columns.Add("译文", propertyTran.PropertyType);



            //}

            object[] values = new object[2];   

            foreach (MemoryFields item in list)

            {

                //for (int i = 0; i < values.Length; i++)

                //{

                values[0] = properties["Orig"].GetValue(item);

                values[1] = properties["Tran"].GetValue(item);

                //}

                dt.Rows.Add(values);

            }

            return dt;

        }

　　

        private string filename = "";

        private IWorkbook workbook = null;

        private FileStream fs = null;

        private bool disposed;

        /// <summary>

        /// 到处到Excel

        /// </summary>

        /// <param name="FileName">导出文件名</param>

        /// <param name="data">table</param>

        /// <param name="sheetName">sheetName</param>

        /// <param name="isColumnWritten"></param>

        /// <returns></returns>

        public int DataTableToExcel(string FileName, System.Data.DataTable data, string sheetName, bool isColumnWritten)

        {

            filename = FileName;

            int i = 0;

            int j = 0;

            int count = 0;

            ISheet sheet = null;



            fs = new FileStream(filename, FileMode.OpenOrCreate, FileAccess.ReadWrite);

            if (filename.IndexOf(".xlsx") > 0) // 2007版本

                workbook = new XSSFWorkbook();

            else if (filename.IndexOf(".xls") > 0) // 2003版本

                workbook = new HSSFWorkbook();

            try

            {

                if (workbook != null)

                {

                    sheet = workbook.CreateSheet(sheetName);

                }

                else

                {

                    return -1;

                }



                if (isColumnWritten == true) //写入DataTable的列名

                {

                    IRow row = sheet.CreateRow(0);

                    for (j = 0; j < data.Columns.Count; ++j)

                    {

                        row.CreateCell(j).SetCellValue(data.Columns[j].ColumnName);

                    }

                    count = 1;

                }

                else

                {

                    count = 0;

                }



                for (i = 0; i < data.Rows.Count; ++i)

                {

                    IRow row = sheet.CreateRow(count);

                    for (j = 0; j < data.Columns.Count; ++j)

                    {

                        row.CreateCell(j).SetCellValue(data.Rows[i][j].ToString());

                    }

                    ++count;

                }

                workbook.Write(fs);  //写入到excel

                return count;

            }

            catch (Exception ex)

            {

                Console.WriteLine("Exception: " + ex.Message);

                return -1;

            }

        }