NPOI操作excel之读取excel数据

NPOI 是 POI 项目的 .NET 版本。POI是一个开源的Java读写Excel、WORD等微软OLE2组件文档的项目。

 一、下载引用

去NPOI官网http://npoi.codeplex.com/下载需要引用的dll，即：NPOI.dll，NPOI.OOXML.dll，NPOI.OpenXml4Net.dll，ICSharpCode.SharpZipLib.dll（office2007版需要此dll）。

二、Excel转datatable类

excel数据：

Excel转datatable类如下：

 using System;
 using System.Data;
 using System.IO;
 using NPOI.SS.UserModel;
 using NPOI.XSSF.UserModel;
 using NPOI.HSSF.UserModel;

 namespace NPOIOprateExcel
 {
     public class ExcelUtility
     {
         /// <summary>
         /// 将excel导入到datatable
         /// </summary>
         /// <param name="filePath">excel路径</param>
         /// <param name="isColumnName">第一行是否是列名</param>
         /// <returns>返回datatable</returns>
         public static DataTable ExcelToDataTable(string filePath, bool isColumnName)
         {
             DataTable dataTable = null;
             FileStream fs = null;
             DataColumn column = null;
             DataRow dataRow = null;
             IWorkbook workbook = null;
             ISheet sheet = null;
             IRow row = null;
             ICell cell = null;
             int startRow = ;
             try
             {
                 using (fs = File.OpenRead(filePath))
                 {
                     // 2007版本
                     if (filePath.IndexOf(".xlsx") > )
                         workbook = new XSSFWorkbook(fs);
                     // 2003版本
                     else if (filePath.IndexOf(".xls") > )
                         workbook = new HSSFWorkbook(fs);

                     if (workbook != null)
                     {
                         sheet = workbook.GetSheetAt();//读取第一个sheet，当然也可以循环读取每个sheet
                         dataTable = new DataTable();
                         if (sheet != null)
                         {
                             int rowCount = sheet.LastRowNum;//总行数
                             if (rowCount > )
                             {
                                 IRow firstRow = sheet.GetRow();//第一行
                                 int cellCount = firstRow.LastCellNum;//列数

                                 //构建datatable的列
                                 if (isColumnName)
                                 {
                                     startRow = ;//如果第一行是列名，则从第二行开始读取
                                     for (int i = firstRow.FirstCellNum; i < cellCount; ++i)
                                     {
                                         cell = firstRow.GetCell(i);
                                         if (cell != null)
                                         {
                                             if (cell.StringCellValue != null)
                                             {
                                                 column = new DataColumn(cell.StringCellValue);
                                                 dataTable.Columns.Add(column);
                                             }
                                         }
                                     }
                                 }
                                 else
                                 {
                                     for (int i = firstRow.FirstCellNum; i < cellCount; ++i)
                                     {
                                         column = new DataColumn("column" + (i + ));
                                         dataTable.Columns.Add(column);
                                     }
                                 }

                                 //填充行
                                 for (int i = startRow; i <= rowCount; ++i)
                                 {
                                     row = sheet.GetRow(i);
                                     if (row == null) continue;

                                     dataRow = dataTable.NewRow();
                                     for (int j = row.FirstCellNum; j < cellCount; ++j)
                                     {
                                         cell = row.GetCell(j);
                                         if (cell == null)
                                         {
                                             dataRow[j] = "";
                                         }
                                         else
                                         {
                                             //CellType(Unknown = -1,Numeric = 0,String = 1,Formula = 2,Blank = 3,Boolean = 4,Error = 5,)
                                             switch (cell.CellType)
                                             {
                                                 case CellType.Blank:
                                                     dataRow[j] = "";
                                                     break;
                                                 case CellType.Numeric:
                                                     short format = cell.CellStyle.DataFormat;
                                                     //对时间格式（2015.12.5、2015/12/5、2015-12-5等）的处理
                                                     if (format ==  || format ==  || format ==  || format == )
                                                         dataRow[j] = cell.DateCellValue;
                                                     else
                                                         dataRow[j] = cell.NumericCellValue;
                                                     break;
                                                 case CellType.String:
                                                     dataRow[j] = cell.StringCellValue;
                                                     break;
                                             }
                                         }
                                     }
                                     dataTable.Rows.Add(dataRow);
                                 }
                             }
                         }
                     }
                 }
                 return dataTable;
             }
             catch (Exception)
             {
                 if (fs != null)
                 {
                     fs.Close();
                 }
                 return null;
             }
         }
     }
 }

三、返回结果

调用上述方法：

private void ReadExcelData()
        {
            DataTable dataTable = null;//接受从excel读取的数据
            string filePath = MapPath("/ExcelFile/excel1.xls");//文件路径姑且写死
            dataTable = ExcelUtility.ExcelToDataTable(filePath, true);
        }

返回的datatable如下：

以上就是NPOI读取excel的方法，接下来就可以把datatable插入数据库了，此处省略。