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。
