NPOI：如何使用NPOI读取文件
我发现NPOI非常适合用C＃编写Excel文件。 但是我想用C＃打开，阅读和修改Excel文件。
我怎样才能做到这一点？
简单阅读下面的例子：
using NPOI.HSSF.UserModel; using NPOI.SS.UserModel; //..... private void button1_Click(object sender, EventArgs e) { HSSFWorkbook hssfwb; using (FileStream file = new FileStream(@"c:\test.xls", FileMode.Open, FileAccess.Read)) { hssfwb= new HSSFWorkbook(file); } ISheet sheet = hssfwb.GetSheet("Arkusz1"); for (int row = 0; row <= sheet.LastRowNum; row++) { if (sheet.GetRow(row) != null) //null is when the row only contains empty cells { MessageBox.Show(string.Format("Row {0} = {1}", row, sheet.GetRow(row).GetCell(0).StringCellValue)); } } } 顺便说一句：在NPOI网站的下载部分有一个示例包 – 一个C＃示例包。 尝试一下，如果你还没有。 🙂
由于工厂方法会为您检测xls或xlsx，所以依靠Workbook工厂实例化工作簿对象可能会有所帮助。 参考： http : //apache-poi.1045710.n5.nabble.com/How-to-check-for-valid-excel-files-using-POI-without-checking-the-file-extension-td2341055.html
IWorkbook workbook = WorkbookFactory.Create(inputStream);
如果您不确定工作表的名称，但是您确定索引（基于0），则可以像这样获取工作表：
ISheet sheet = workbook.GetSheetAt(sheetIndex);
然后，您可以使用mj82接受的答案提供的代码遍历行
我发现NPOI非常有用的工作与Excel文件，这里是我的实现（评论是西class牙语，对不起）：
此方法打开Excel（xls或xlsx）文件并将其转换为DataTable。
/// <summary>Abre un archivo de Excel (xls o xlsx) y lo convierte en un DataTable. /// LA PRIMERA FILA DEBE CONTENER LOS NOMBRES DE LOS CAMPOS.</summary> /// <param name="pRutaArchivo">Ruta completa del archivo a abrir.</param> /// <param name="pHojaIndex">Número (basado en cero) de la hoja que se desea abrir. 0 es la primera hoja.</param> private DataTable Excel_To_DataTable(string pRutaArchivo, int pHojaIndex) { // --------------------------------- // /* REFERENCIAS: * NPOI.dll * NPOI.OOXML.dll * NPOI.OpenXml4Net.dll */ // --------------------------------- // /* USING: * using NPOI.SS.UserModel; * using NPOI.HSSF.UserModel; * using NPOI.XSSF.UserModel; */ // AUTOR: Ing. Jhollman Chacon R. 2015 // --------------------------------- // DataTable Tabla = null; try { if (System.IO.File.Exists(pRutaArchivo)) { IWorkbook workbook = null; //IWorkbook determina si es xls o xlsx ISheet worksheet = null; string first_sheet_name = ""; using (FileStream FS = new FileStream(pRutaArchivo, FileMode.Open, FileAccess.Read)) { workbook = WorkbookFactory.Create(FS); //Abre tanto XLS como XLSX worksheet = workbook.GetSheetAt(pHojaIndex); //Obtener Hoja por indice first_sheet_name = worksheet.SheetName; //Obtener el nombre de la Hoja Tabla = new DataTable(first_sheet_name); Tabla.Rows.Clear(); Tabla.Columns.Clear(); // Leer Fila por fila desde la primera for (int rowIndex = 0; rowIndex <= worksheet.LastRowNum; rowIndex++) { DataRow NewReg = null; IRow row = worksheet.GetRow(rowIndex); IRow row2 = null; IRow row3 = null; if (rowIndex == 0) { row2 = worksheet.GetRow(rowIndex + 1); //Si es la Primera fila, obtengo tambien la segunda para saber el tipo de datos row3 = worksheet.GetRow(rowIndex + 2); //Y la tercera tambien por las dudas } if (row != null) //null is when the row only contains empty cells { if (rowIndex > 0) NewReg = Tabla.NewRow(); int colIndex = 0; //Leer cada Columna de la fila foreach (ICell cell in row.Cells) { object valorCell = null; string cellType = ""; string[] cellType2 = new string[2]; if (rowIndex == 0) //Asumo que la primera fila contiene los titlos: { for (int i = 0; i < 2; i++) { ICell cell2 = null; if (i == 0) { cell2 = row2.GetCell(cell.ColumnIndex); } else { cell2 = row3.GetCell(cell.ColumnIndex); } if (cell2 != null) { switch (cell2.CellType) { case CellType.Blank: break; case CellType.Boolean: cellType2[i] = "System.Boolean"; break; case CellType.String: cellType2[i] = "System.String"; break; case CellType.Numeric: if (HSSFDateUtil.IsCellDateFormatted(cell2)) { cellType2[i] = "System.DateTime"; } else { cellType2[i] = "System.Double"; //valorCell = cell2.NumericCellValue; } break; case CellType.Formula: bool continuar = true; switch (cell2.CachedFormulaResultType) { case CellType.Boolean: cellType2[i] = "System.Boolean"; break; case CellType.String: cellType2[i] = "System.String"; break; case CellType.Numeric: if (HSSFDateUtil.IsCellDateFormatted(cell2)) { cellType2[i] = "System.DateTime"; } else { try { //DETERMINAR SI ES BOOLEANO if (cell2.CellFormula == "TRUE()") { cellType2[i] = "System.Boolean"; continuar = false; } if (continuar && cell2.CellFormula == "FALSE()") { cellType2[i] = "System.Boolean"; continuar = false; } if (continuar) { cellType2[i] = "System.Double"; continuar = false; } } catch { } } break; } break; default: cellType2[i] = "System.String"; break; } } } //Resolver las diferencias de Tipos if (cellType2[0] == cellType2[1]) { cellType = cellType2[0]; } else { if (cellType2[0] == null) cellType = cellType2[1]; if (cellType2[1] == null) cellType = cellType2[0]; if (cellType == "") cellType = "System.String"; } //Obtener el nombre de la Columna string colName = "Column_{0}"; try { colName = cell.StringCellValue; } catch { colName = string.Format(colName, colIndex); } //Verificar que NO se repita el Nombre de la Columna foreach (DataColumn col in Tabla.Columns) { if (col.ColumnName == colName) colName = string.Format("{0}_{1}", colName, colIndex); } //Agregar el campos de la tabla: DataColumn codigo = new DataColumn(colName, System.Type.GetType(cellType)); Tabla.Columns.Add(codigo); colIndex++; } else { //Las demas filas son registros: switch (cell.CellType) { case CellType.Blank: valorCell = DBNull.Value; break; case CellType.Boolean: valorCell = cell.BooleanCellValue; break; case CellType.String: valorCell = cell.StringCellValue; break; case CellType.Numeric: if (HSSFDateUtil.IsCellDateFormatted(cell)) { valorCell = cell.DateCellValue; } else { valorCell = cell.NumericCellValue; } break; case CellType.Formula: switch (cell.CachedFormulaResultType) { case CellType.Blank: valorCell = DBNull.Value; break; case CellType.String: valorCell = cell.StringCellValue; break; case CellType.Boolean: valorCell = cell.BooleanCellValue; break; case CellType.Numeric: if (HSSFDateUtil.IsCellDateFormatted(cell)) { valorCell = cell.DateCellValue; } else { valorCell = cell.NumericCellValue; } break; } break; default: valorCell = cell.StringCellValue; break; } //Agregar el nuevo Registro if (cell.ColumnIndex <= Tabla.Columns.Count - 1) NewReg[cell.ColumnIndex] = valorCell; } } } if (rowIndex > 0) Tabla.Rows.Add(NewReg); } Tabla.AcceptChanges(); } } else { throw new Exception("ERROR 404: El archivo especificado NO existe."); } } catch (Exception ex) { throw ex; } return Tabla; }
这第二种方法做反例，将一个DataTable保存到一个Excel文件，是啊，它可以是xls或新的xlsx，你的select！
/// <summary>Convierte un DataTable en un archivo de Excel (xls o Xlsx) y lo guarda en disco.</summary> /// <param name="pDatos">Datos de la Tabla a guardar. Usa el nombre de la tabla como nombre de la Hoja</param> /// <param name="pFilePath">Ruta del archivo donde se guarda.</param> private void DataTable_To_Excel(DataTable pDatos, string pFilePath) { try { if (pDatos != null && pDatos.Rows.Count > 0) { IWorkbook workbook = null; ISheet worksheet = null; using (FileStream stream = new FileStream(pFilePath, FileMode.Create, FileAccess.ReadWrite)) { string Ext = System.IO.Path.GetExtension(pFilePath); //<-Extension del archivo switch (Ext.ToLower()) { case ".xls": HSSFWorkbook workbookH = new HSSFWorkbook(); NPOI.HPSF.DocumentSummaryInformation dsi = NPOI.HPSF.PropertySetFactory.CreateDocumentSummaryInformation(); dsi.Company = "Cutcsa"; dsi.Manager = "Departamento Informatico"; workbookH.DocumentSummaryInformation = dsi; workbook = workbookH; break; case ".xlsx": workbook = new XSSFWorkbook(); break; } worksheet = workbook.CreateSheet(pDatos.TableName); //<-Usa el nombre de la tabla como nombre de la Hoja //CREAR EN LA PRIMERA FILA LOS TITULOS DE LAS COLUMNAS int iRow = 0; if (pDatos.Columns.Count > 0) { int iCol = 0; IRow fila = worksheet.CreateRow(iRow); foreach (DataColumn columna in pDatos.Columns) { ICell cell = fila.CreateCell(iCol, CellType.String); cell.SetCellValue(columna.ColumnName); iCol++; } iRow++; } //FORMATOS PARA CIERTOS TIPOS DE DATOS ICellStyle _doubleCellStyle = workbook.CreateCellStyle(); _doubleCellStyle.DataFormat = workbook.CreateDataFormat().GetFormat("#,##0.###"); ICellStyle _intCellStyle = workbook.CreateCellStyle(); _intCellStyle.DataFormat = workbook.CreateDataFormat().GetFormat("#,##0"); ICellStyle _boolCellStyle = workbook.CreateCellStyle(); _boolCellStyle.DataFormat = workbook.CreateDataFormat().GetFormat("BOOLEAN"); ICellStyle _dateCellStyle = workbook.CreateCellStyle(); _dateCellStyle.DataFormat = workbook.CreateDataFormat().GetFormat("dd-MM-yyyy"); ICellStyle _dateTimeCellStyle = workbook.CreateCellStyle(); _dateTimeCellStyle.DataFormat = workbook.CreateDataFormat().GetFormat("dd-MM-yyyy HH:mm:ss"); //AHORA CREAR UNA FILA POR CADA REGISTRO DE LA TABLA foreach (DataRow row in pDatos.Rows) { IRow fila = worksheet.CreateRow(iRow); int iCol = 0; foreach (DataColumn column in pDatos.Columns) { ICell cell = null; //<-Representa la celda actual object cellValue = row[iCol]; //<- El valor actual de la celda switch (column.DataType.ToString()) { case "System.Boolean": if (cellValue != DBNull.Value) { cell = fila.CreateCell(iCol, CellType.Boolean); if (Convert.ToBoolean(cellValue)) { cell.SetCellFormula("TRUE()"); } else { cell.SetCellFormula("FALSE()"); } cell.CellStyle = _boolCellStyle; } break; case "System.String": if (cellValue != DBNull.Value) { cell = fila.CreateCell(iCol, CellType.String); cell.SetCellValue(Convert.ToString(cellValue)); } break; case "System.Int32": if (cellValue != DBNull.Value) { cell = fila.CreateCell(iCol, CellType.Numeric); cell.SetCellValue(Convert.ToInt32(cellValue)); cell.CellStyle = _intCellStyle; } break; case "System.Int64": if (cellValue != DBNull.Value) { cell = fila.CreateCell(iCol, CellType.Numeric); cell.SetCellValue(Convert.ToInt64(cellValue)); cell.CellStyle = _intCellStyle; } break; case "System.Decimal": if (cellValue != DBNull.Value) { cell = fila.CreateCell(iCol, CellType.Numeric); cell.SetCellValue(Convert.ToDouble(cellValue)); cell.CellStyle = _doubleCellStyle; } break; case "System.Double": if (cellValue != DBNull.Value) { cell = fila.CreateCell(iCol, CellType.Numeric); cell.SetCellValue(Convert.ToDouble(cellValue)); cell.CellStyle = _doubleCellStyle; } break; case "System.DateTime": if (cellValue != DBNull.Value) { cell = fila.CreateCell(iCol, CellType.Numeric); cell.SetCellValue(Convert.ToDateTime(cellValue)); //Si No tiene valor de Hora, usar formato dd-MM-yyyy DateTime cDate = Convert.ToDateTime(cellValue); if (cDate != null && cDate.Hour > 0) { cell.CellStyle = _dateTimeCellStyle; } else { cell.CellStyle = _dateCellStyle; } } break; default: break; } iCol++; } iRow++; } workbook.Write(stream); stream.Close(); } } } catch (Exception ex) { throw ex; } }
使用这两种方法，您可以打开Excel文件，将其加载到DataTable中，进行修改并将其保存回Excel文件中。
希望你们find这个有用的。
private DataTable GetDataTableFromExcel(String Path) { XSSFWorkbook wb; XSSFSheet sh; String Sheet_name; using (var fs = new FileStream(Path, FileMode.Open, FileAccess.Read)) { wb = new XSSFWorkbook(fs); Sheet_name= wb.GetSheetAt(0).SheetName; //get first sheet name } DataTable DT = new DataTable(); DT.Rows.Clear(); DT.Columns.Clear(); // get sheet sh = (XSSFSheet)wb.GetSheet(Sheet_name); int i = 0; while (sh.GetRow(i) != null) { // add neccessary columns if (DT.Columns.Count < sh.GetRow(i).Cells.Count) { for (int j = 0; j < sh.GetRow(i).Cells.Count; j++) { DT.Columns.Add("", typeof(string)); } } // add row DT.Rows.Add(); // write row value for (int j = 0; j < sh.GetRow(i).Cells.Count; j++) { var cell = sh.GetRow(i).GetCell(j); if (cell != null) { // TODO: you can add more cell types capatibility, eg formula switch (cell.CellType) { case NPOI.SS.UserModel.CellType.Numeric: DT.Rows[i][j] = sh.GetRow(i).GetCell(j).NumericCellValue; //dataGridView1[j, i].Value = sh.GetRow(i).GetCell(j).NumericCellValue; break; case NPOI.SS.UserModel.CellType.String: DT.Rows[i][j] = sh.GetRow(i).GetCell(j).StringCellValue; break; } } } i++; } return DT; }
private static ISheet GetFileStream(string fullFilePath) { var fileExtension = Path.GetExtension(fullFilePath); string sheetName; ISheet sheet = null; switch (fileExtension) { case ".xlsx": using (var fs = new FileStream(fullFilePath, FileMode.Open, FileAccess.Read)) { var wb = new XSSFWorkbook(fs); sheetName = wb.GetSheetAt(0).SheetName; sheet = (XSSFSheet) wb.GetSheet(sheetName); } break; case ".xls": using (var fs = new FileStream(fullFilePath, FileMode.Open, FileAccess.Read)) { var wb = new HSSFWorkbook(fs); sheetName = wb.GetSheetAt(0).SheetName; sheet = (HSSFSheet) wb.GetSheet(sheetName); } break; } return sheet; } private static DataTable GetRequestsDataFromExcel(string fullFilePath) { try { var sh = GetFileStream(fullFilePath); var dtExcelTable = new DataTable(); dtExcelTable.Rows.Clear(); dtExcelTable.Columns.Clear(); var headerRow = sh.GetRow(0); int colCount = headerRow.LastCellNum; for (var c = 0; c < colCount; c++) dtExcelTable.Columns.Add(headerRow.GetCell(c).ToString()); var i = 1; var currentRow = sh.GetRow(i); while (currentRow != null) { var dr = dtExcelTable.NewRow(); for (var j = 0; j < currentRow.Cells.Count; j++) { var cell = currentRow.GetCell(j); if (cell != null) switch (cell.CellType) { case CellType.Numeric: dr[j] = DateUtil.IsCellDateFormatted(cell) ? cell.DateCellValue.ToString(CultureInfo.InvariantCulture) : cell.NumericCellValue.ToString(CultureInfo.InvariantCulture); break; case CellType.String: dr[j] = cell.StringCellValue; break; case CellType.Blank: dr[j] = string.Empty; break; } } dtExcelTable.Rows.Add(dr); i++; currentRow = sh.GetRow(i); } return dtExcelTable; } catch (Exception e) { throw; } }
