本文实例展示了WinForm项目开发中NPOI用法，对于C#初学者有一定的借鉴价值。具体实例如下：

private void ExportMergeExcel(){ if (File.Exists(templateXlsPath)) { int i = 4, _recordNo = 1; using (FileStream file = new FileStream(templateXlsPath, FileMode.Open, FileAccess.Read)) { HSSFWorkbook _excel = new HSSFWorkbook(file); ICellStyle _cellStyle = CreateCellStly(_excel); ISheet _sheetBasic = _excel.GetSheet(ExcelReadHelper.sheet_BasicInfo.Replace("$", "")); ISheet _sheetStreatLamp = _excel.GetSheet(ExcelReadHelper.sheet_LampMoreLess.Replace("$", "")); ISheet _sheetBasicEx = _excel.GetSheet(ExcelReadHelper.sheet_BasicExInfo.Replace("$", "")); ISheet _sheetStreatLampEx = _excel.GetSheet(ExcelReadHelper.sheet_LampMoreLessExInfo.Replace("$", "")); ISheet _sheetBasicTeamEx = _excel.GetSheet(ExcelReadHelper.sheet_BasicTeamStatistics.Replace("$", "")); ISheet _sheetBasicLampTypeEx = _excel.GetSheet(ExcelReadHelper.sheet_BasicTypeStatistics.Replace("$", "")); ISheet _sheetStreetLampMLEx = _excel.GetSheet(ExcelReadHelper.sheet_LampMoreLessTeamStatistics.Replace("$", "")); ISheet _sheetStreetLampTeamML = _excel.GetSheet(ExcelReadHelper.sheet_LampMoreLessTypeStatistics.Replace("$", "")); file.Close(); FillBasicSheetDb(_sheetBasic, i, _recordNo); _recordNo = 1; i = 4; FillStreetLampDb(_sheetStreatLamp, i, _recordNo); _recordNo = 1; i = 4; FillBasicExSheetDb(_sheetBasicEx, i, _recordNo); _recordNo = 1; i = 4; FillStreetLampExDb(_sheetStreatLampEx, i, _recordNo); i = 1; IRow _rowSum = null; int _lampTotalLampCnt = 0, _colLampCnt = 0, _ncolLampCnt = 0; double _lampTotalLampPw = 0, _colLampPw = 0, _ncolLampPw = 0; FillBasicTeamExSheetDb(_excel, _rowSum, _sheetBasicTeamEx, _cellStyle, i, _lampTotalLampCnt, _colLampCnt, _ncolLampCnt, _lampTotalLampPw, _colLampPw, _ncolLampPw); i = 1; _lampTotalLampCnt = 0; _colLampCnt = 0; _ncolLampCnt = 0; _lampTotalLampPw = 0; _colLampPw = 0; _ncolLampPw = 0; FillbasicLampTypeExSheetDb(_excel, _rowSum, _sheetBasicLampTypeEx, _cellStyle, i, _lampTotalLampCnt, _colLampCnt, _ncolLampCnt, _lampTotalLampPw, _colLampPw, _ncolLampPw); _lampTotalLampCnt = 0; _lampTotalLampPw = 0; i = 1; FillsheetStreetLampMLSheetDb(_excel, _rowSum, _sheetStreetLampMLEx, _cellStyle, i, _lampTotalLampCnt, _lampTotalLampPw); _lampTotalLampCnt = 0; _lampTotalLampPw = 0; i = 1; FillStreetLampTeamMLSheetDb(_excel, _rowSum, _sheetStreetLampTeamML, _cellStyle, i, _lampTotalLampCnt, _lampTotalLampPw); OutPutMergeExcel(_excel); } }}private void FillBasicTeamExSheetDb(HSSFWorkbook _excel, IRow _rowSum, ISheet _sheetBasicTeamEx, ICellStyle _cellStyle, int i, int _lampTotalLampCnt, int _colLampCnt, int _ncolLampCnt, double _lampTotalLampPw, double _colLampPw, double _ncolLampPw){ foreach (ExcelStatistics excelBasicEx in basicTeamExList) { IRow _row = _sheetBasicTeamEx.CreateRow(i); ExcelWriteHelper.CreateStatisticsExcelRow(_row, excelBasicEx, "BasicTeam"); #region 总灯数 int _lTotalLampCnt = 0; int.TryParse(excelBasicEx.LampCount, out _lTotalLampCnt); _lampTotalLampCnt += _lTotalLampCnt; #endregion #region 总计算功率(KW) double _lTotalLampPw = 0; double.TryParse(excelBasicEx.LampPower, out _lTotalLampPw); _lampTotalLampPw += _lTotalLampPw; #endregion #region 汇总灯数 int _cLampCount = 0; int.TryParse(excelBasicEx.CollectCount, out _cLampCount); _colLampCnt += _cLampCount; #endregion #region 汇总功率(KW) double _cLampPw = 0; double.TryParse(excelBasicEx.CollectPower, out _cLampPw); _colLampPw += _cLampPw; #endregion #region 非汇总灯数 int _ncLampCount = 0; int.TryParse(excelBasicEx.NotCollectCount, out _ncLampCount); _ncolLampCnt += _ncLampCount; #endregion #region 非汇总功率(KW) double _ncLampPw = 0; double.TryParse(excelBasicEx.NotCollectPower, out _ncLampPw); _ncolLampPw += _ncLampPw; #endregion i++; } _rowSum = _sheetBasicTeamEx.CreateRow(i); _rowSum.HeightInPoints = 20; _rowSum.CreateCell(0).SetCellValue("合计："); _rowSum.CreateCell(1).SetCellValue(_lampTotalLampCnt); _rowSum.CreateCell(2).SetCellValue(_lampTotalLampPw); _rowSum.CreateCell(3).SetCellValue(_colLampCnt); _rowSum.CreateCell(4).SetCellValue(_colLampPw); _rowSum.CreateCell(5).SetCellValue(_ncolLampCnt); _rowSum.CreateCell(6).SetCellValue(_ncolLampPw); SetRowStyle(_rowSum, _cellStyle);}

定义样式：

/// <summary>/// 样式创建/// eg:///private ICellStyle CreateCellStly(HSSFWorkbook _excel)///{/// IFont _font = _excel.CreateFont();/// _font.FontHeightInPoints = 11;/// _font.FontName = "宋体";/// _font.Boldweight = (short)FontBoldWeight.Bold;/// ICellStyle _cellStyle = _excel.CreateCellStyle();/// //_cellStyle.FillForegroundColor = NPOI.HSSF.Util.HSSFColor.LightGreen.Index;/// //_cellStyle.FillPattern = NPOI.SS.UserModel.FillPattern.SolidForeground;/// _cellStyle.SetFont(_font);/// return _cellStyle;///}/// 为行设置样式/// </summary>/// <param name="row">IRow</param>/// <param name="cellStyle">ICellStyle</param>public static void SetRowStyle(this IRow row, ICellStyle cellStyle){ if (row != null && cellStyle != null) { for (int u = row.FirstCellNum; u < row.LastCellNum; u++) { ICell _cell = row.GetCell(u); if (_cell != null) _cell.CellStyle = cellStyle; } }}