在C#中使用NPOI2.0操作Excel2003和Excel2007

http://blog.csdn.net/halym/article/details/9235823

在C#中使用NPOI2.0操作Excel2003和Excel2007

Excel2003：

 #region Excel2003
 ///
 /// 将Excel文件中的数据读出到DataTable中(xls)
 ///
 ///
 ///
 public static DataTable ExcelToTableForXLS(string file)
 {
     DataTable dt = new DataTable();
     using (FileStream fs = new FileStream(file, FileMode.Open, FileAccess.Read))
     {
         XLS.HSSFWorkbook hssfworkbook = new XLS.HSSFWorkbook(fs);
         ISheet sheet = hssfworkbook.GetSheetAt(0);

         //表头
         IRow header = sheet.GetRow(sheet.FirstRowNum);
         List<int> columns = new List<int>();
         for (int i = 0; i < header.LastCellNum; i++)
         {
             object obj = GetValueTypeForXLS(header.GetCell(i) as XLS.HSSFCell);
             if (obj == null || obj.ToString() == string.Empty)
             {
                 dt.Columns.Add(new DataColumn("Columns" + i.ToString()));
                 //continue;
             }
             else
                 dt.Columns.Add(new DataColumn(obj.ToString()));
             columns.Add(i);
         }
         //数据
         for (int i = sheet.FirstRowNum + 1; i <= sheet.LastRowNum; i++)
         {
             DataRow dr = dt.NewRow();
             bool hasValue = false;
             foreach (int j in columns)
             {
                 dr[j] = GetValueTypeForXLS(sheet.GetRow(i).GetCell(j) as XLS.HSSFCell);
                 if (dr[j] != null && dr[j].ToString() != string.Empty)
                 {
                     hasValue = true;
                 }
             }
             if (hasValue)
             {
                 dt.Rows.Add(dr);
             }
         }
     }
     return dt;
 }

 ///
 /// 将DataTable数据导出到Excel文件中(xls)
 ///
 ///
 ///
 public static void TableToExcelForXLS(DataTable dt, string file)
 {
     XLS.HSSFWorkbook hssfworkbook = new XLS.HSSFWorkbook();
     ISheet sheet = hssfworkbook.CreateSheet("Test");

     //表头
     IRow row = sheet.CreateRow(0);
     for (int i = 0; i < dt.Columns.Count; i++)
     {
         ICell cell = row.CreateCell(i);
         cell.SetCellValue(dt.Columns[i].ColumnName);
     }

     //数据
     for (int i = 0; i < dt.Rows.Count; i++)
     {
         IRow row1 = sheet.CreateRow(i + 1);
         for (int j = 0; j < dt.Columns.Count; j++)
         {
             ICell cell = row1.CreateCell(j);
             cell.SetCellValue(dt.Rows[i][j].ToString());
         }
     }

     //转为字节数组
     MemoryStream stream = new MemoryStream();
     hssfworkbook.Write(stream);
     var buf = stream.ToArray();

     //保存为Excel文件
     using (FileStream fs = new FileStream(file, FileMode.Create, FileAccess.Write))
     {
         fs.Write(buf, 0, buf.Length);
         fs.Flush();
     }
 }

 ///
 /// 获取单元格类型(xls)
 ///
 ///
 ///
 private static object GetValueTypeForXLS(XLS.HSSFCell cell)
 {
     if (cell == null)
         return null;
     switch (cell.CellType)
     {
         case CellType.BLANK: //BLANK:
             return null;
         case CellType.BOOLEAN: //BOOLEAN:
             return cell.BooleanCellValue;
         case CellType.NUMERIC: //NUMERIC:
             return cell.NumericCellValue;
         case CellType.STRING: //STRING:
             return cell.StringCellValue;
         case CellType.ERROR: //ERROR:
             return cell.ErrorCellValue;
         case CellType.FORMULA: //FORMULA:
         default:
             return "=" + cell.CellFormula;
     }
 }
 #endregion

Excel2007：

 #region Excel2007
 ///
 /// 将Excel文件中的数据读出到DataTable中(xlsx)
 ///
 ///
 ///
 public static DataTable ExcelToTableForXLSX(string file)
 {
     DataTable dt = new DataTable();
     using (FileStream fs = new FileStream(file, FileMode.Open, FileAccess.Read))
     {
         XSSFWorkbook xssfworkbook = new XSSFWorkbook(fs);
         ISheet sheet = xssfworkbook.GetSheetAt(0);

         //表头
         IRow header = sheet.GetRow(sheet.FirstRowNum);
         List<int> columns = new List<int>();
         for (int i = 0; i < header.LastCellNum; i++)
         {
             object obj = GetValueTypeForXLSX(header.GetCell(i) as XSSFCell);
             if (obj == null || obj.ToString() == string.Empty)
             {
                 dt.Columns.Add(new DataColumn("Columns" + i.ToString()));
                 //continue;
             }
             else
                 dt.Columns.Add(new DataColumn(obj.ToString()));
             columns.Add(i);
         }
         //数据
         for (int i = sheet.FirstRowNum + 1; i <= sheet.LastRowNum; i++)
         {
             DataRow dr = dt.NewRow();
             bool hasValue = false;
             foreach (int j in columns)
             {
                 dr[j] = GetValueTypeForXLSX(sheet.GetRow(i).GetCell(j) as XSSFCell);
                 if (dr[j] != null && dr[j].ToString() != string.Empty)
                 {
                     hasValue = true;
                 }
             }
             if (hasValue)
             {
                 dt.Rows.Add(dr);
             }
         }
     }
     return dt;
 }

 ///
 /// 将DataTable数据导出到Excel文件中(xlsx)
 ///
 ///
 ///
 public static void TableToExcelForXLSX(DataTable dt, string file)
 {
     XSSFWorkbook xssfworkbook = new XSSFWorkbook();
     ISheet sheet = xssfworkbook.CreateSheet("Test");

     //表头
     IRow row = sheet.CreateRow(0);
     for (int i = 0; i < dt.Columns.Count; i++)
     {
         ICell cell = row.CreateCell(i);
         cell.SetCellValue(dt.Columns[i].ColumnName);
     }

     //数据
     for (int i = 0; i < dt.Rows.Count; i++)
     {
         IRow row1 = sheet.CreateRow(i + 1);
         for (int j = 0; j < dt.Columns.Count; j++)
         {
             ICell cell = row1.CreateCell(j);
             cell.SetCellValue(dt.Rows[i][j].ToString());
         }
     }

     //转为字节数组
     MemoryStream stream = new MemoryStream();
     xssfworkbook.Write(stream);
     var buf = stream.ToArray();

     //保存为Excel文件
     using (FileStream fs = new FileStream(file, FileMode.Create, FileAccess.Write))
     {
         fs.Write(buf, 0, buf.Length);
         fs.Flush();
     }
 }

 ///
 /// 获取单元格类型(xlsx)
 ///
 ///
 ///
 private static object GetValueTypeForXLSX(XSSFCell cell)
 {
     if (cell == null)
         return null;
     switch (cell.CellType)
     {
         case CellType.BLANK: //BLANK:
             return null;
         case CellType.BOOLEAN: //BOOLEAN:
             return cell.BooleanCellValue;
         case CellType.NUMERIC: //NUMERIC:
             return cell.NumericCellValue;
         case CellType.STRING: //STRING:
             return cell.StringCellValue;
         case CellType.ERROR: //ERROR:
             return cell.ErrorCellValue;
         case CellType.FORMULA: //FORMULA:
         default:
             return "=" + cell.CellFormula;
     }
 }

注意：操作Excel2003与操作Excel2007使用的是不同的命名空间下的内容

使用NPOI.HSSF.UserModel空间下的HSSFWorkbook操作Excel2003

使用NPOI.XSSF.UserModel空间下的XSSFWorkbook操作Excel2007