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);
            }