C#导出Excel

最近在做C#导出excel，虽然以也做过，但是数据量没有现在这么多的。

第一种方法就是以后组件的方式来做：

  //public static void OutExcel(List<SubStationRealtimedata> listData, string str)

        //{

        //     Microsoft.Office.Interop.Excel.Application excelApp = new Application();

        //     Microsoft.Office.Interop.Excel.Workbook wbook = null;

        //     Microsoft.Office.Interop.Excel.Sheets sheets =null;

        //     Microsoft.Office.Interop.Excel.Worksheet wkSheet = null;



        //     Microsoft.Office.Interop.Excel.Range range = null;

        //     Microsoft.Office.Interop.Excel.Range rangeWire = null;



        //     wbook = excelApp.Workbooks.Add(true);

        //     sheets = wbook.Worksheets;

        //     wkSheet = (Worksheet)sheets.get_Item(1);



        //     System.Windows.Forms.Application.DoEvents();



        //     range = wkSheet.get_Range("A1", Missing.Value);

        //     rangeWire = wkSheet.get_Range("B1", Missing.Value);

        //     range.Value2 = "浙江";

        //     rangeWire.Value2 = "某某线";



        //     wkSheet.Cells[4, 1] = "时间";

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

        //     {

        //         wkSheet.Cells[4, i + 2] = arrayList[i];

        //         int j=5;

        //         foreach(SubStationRealtimedata subdata in listData)

        //         {

        //             wkSheet.Cells[j, 1] = subdata.SendTime;

        //             wkSheet.Cells[j, i + 2] = subdata.CurrentPhaseA;

                     

        //             j++;

        //         }

                

        //     }





        //     wbook.Close();



        //     excelApp.Quit();



        //}

　由于以上种方法速度太慢，后来经过园子的网友推荐用npoi，这种流的方式效率非常高，网上先下载npoi组件。

  SaveFileDialog dialog = new SaveFileDialog();

            dialog.Filter = "Excel文件|*.xls";

            if (dialog.ShowDialog() == DialogResult.No)

            {

                

            }



            string filename = dialog.FileName;

            HSSFWorkbook workbook = new HSSFWorkbook();

            ISheet sheet = workbook.CreateSheet("数据");

            //列表头

            IRow rowheader = sheet.CreateRow(4);

            //这里必须固定

            rowheader.CreateCell(0, CellType.String).SetCellValue("时间");

            for (int i = 1; i <= arrayList.Count; i++)

            {

                rowheader.CreateCell(i, CellType.String).SetCellValue(arrayList[i-1].ToString());

            }



            ArrayList arrayListData = null;



            //内容

            int j = 5;

            foreach (SubStationRealtimedata subdata in listData)

            {



                #region 先放入一个arraylist

                arrayListData = new ArrayList();

                if (pexcel != null)

                {

                    if (pexcel.PCurrentA)

                    {

                        arrayListData.Add(subdata.CurrentPhaseA);

                    }

                    if (pexcel.PCurrentB)

                    {

                        arrayListData.Add(subdata.CurrentPhaseB);

                    }

                    if (pexcel.PCurrentC)

                    {

                        arrayListData.Add(subdata.CurrentPhaseB);

                    }

                    if (pexcel.PVoltageA)

                    {

                        arrayListData.Add(subdata.CurrentPhaseB);

                    }

                    if (pexcel.PVoltageB)

                    {

                        arrayListData.Add(subdata.CurrentPhaseB);

                    }

                    if (pexcel.PVoltageC)

                    {

                        arrayListData.Add(subdata.CurrentPhaseB);

                    }

                    if (pexcel.PharmonicPrecent3)

                    {

                        arrayListData.Add(subdata.harmonicPrecent3);

                    }

                    if (pexcel.PharmonicPrecent5)

                    {

                        arrayListData.Add(subdata.harmonicPrecent5);

                    }

                    if (pexcel.PharmonicPrecent7)

                    {

                        arrayListData.Add(subdata.harmonicPrecent7);

                    }

                    if (pexcel.PharmonicPrecent9)

                    {

                        arrayListData.Add(subdata.harmonicPrecent9);

                    }

                    if (pexcel.PharmonicPrecent11)

                    {

                        arrayListData.Add(subdata.harmonicPrecent11);

                    }

                    if (pexcel.PharmonicPrecent13)

                    {

                        arrayListData.Add(subdata.harmonicPrecent13);

                    }

                    if (pexcel.PActive)

                    {

                        arrayListData.Add(subdata.Active);

                    }

                    if (pexcel.PReactive)

                    {

                        arrayListData.Add(subdata.Reactive);

                    }

                }

                #endregion



                IRow rowcontent = sheet.CreateRow(j);

                rowcontent.CreateCell(0, CellType.String).SetCellValue(subdata.SendTime);

                for (int i = 1; i <= arrayListData.Count; i++)

                {

                    rowcontent.CreateCell(i, CellType.String).SetCellValue(arrayListData[i-1].ToString());

                }

                j++;

            }





       //最后输出流就可以了。呵呵！非常方便。

            using (Stream stream = File.OpenWrite(filename))

            {

                workbook.Write(stream);

            }