什么是NPOI
该项目是位于http://poi.apache.org/的POI Java项目的.NET版本。POI是一个开源项目，可以帮助您读取/写入xls，doc，ppt文件。它有着广泛的应用。本文给大家介绍ASP.Net MVC利用NPOI导入导出Excel的问题。
因近期项目遇到所以记录一下：
首先导出Excel：
首先引用NPOI包
（Action一定要用FileResult）
/// <summary>
/// 批量导出本校第一批派位学生
/// </summary>
/// <returns></returns>
public FileResult ExportStu2()
{
string schoolname = "401";
//创建Excel文件的对象
NPOI.HSSF.UserModel.HSSFWorkbook book = new NPOI.HSSF.UserModel.HSSFWorkbook();
//添加一个sheet
NPOI.SS.UserModel.ISheet sheet1 = book.CreateSheet("Sheet1");
//获取list数据
List<TB_STUDENTINFOModel> listRainInfo = m_BLL.GetSchoolListAATQ(schoolname);
//给sheet1添加第一行的头部标题
NPOI.SS.UserModel.IRow row1 = sheet1.CreateRow(0);
row1.CreateCell(0).SetCellValue("电脑号");
row1.CreateCell(1).SetCellValue("姓名");
//将数据逐步写入sheet1各个行
for (int i = 0; i < listRainInfo.Count; i++)
{
NPOI.SS.UserModel.IRow rowtemp = sheet1.CreateRow(i + 1);
rowtemp.CreateCell(0).SetCellValue(listRainInfo[i].ST_CODE.ToString());
rowtemp.CreateCell(1).SetCellValue(listRainInfo[i].ST_NAME.ToString());
}
// 写入到客户端
System.IO.MemoryStream ms = new System.IO.MemoryStream();
book.Write(ms);
ms.Seek(0, SeekOrigin.Begin);
return File(ms, "application/vnd.ms-excel", "第一批电脑派位生名册.xls");
}前台直接写就可实现：
@Html.ActionLink("点击导出名册", "ExportStu2")下面说一下导入：
首先说一些前台吧，mvc上传注意必须加new { enctype = "multipart/form-data" }：
<td>
2、@using(@Html.BeginForm("ImportStu", "ProSchool", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
<text>选择上传文件：（工作表名为“Sheet1”，“电脑号”在A1单元格。）</text>
<input name="file" type="file" id="file" />
<input type="submit" name="Upload" value="批量导入第一批电脑派位名册" />
}
</td>后台实现：只传路径得出DataTable：
/// <summary>
/// Excel导入
/// </summary>
/// <param name="filePath"></param>
/// <returns></returns>
public DataTable ImportExcelFile(string filePath)
{
HSSFWorkbook hssfworkbook;
#region//初始化信息
try
{
using (FileStream file = new FileStream(filePath, FileMode.Open, FileAccess.Read))
{
hssfworkbook = new HSSFWorkbook(file);
}
}
catch (Exception e)
{
throw e;
}
#endregion
using (NPOI.SS.UserModel.ISheet sheet = hssfworkbook.GetSheetAt(0))
{
DataTable table = new DataTable();
IRow headerRow = sheet.GetRow(0);//第一行为标题行
int cellCount = headerRow.LastCellNum;//LastCellNum = PhysicalNumberOfCells
int rowCount = sheet.LastRowNum;//LastRowNum = PhysicalNumberOfRows - 1
//handling header.
for (int i = headerRow.FirstCellNum; i < cellCount; i++)
{
DataColumn column = new DataColumn(headerRow.GetCell(i).StringCellValue);
table.Columns.Add(column);
}
for (int i = (sheet.FirstRowNum + 1); i <= rowCount; i++)
{
IRow row = sheet.GetRow(i);
DataRow dataRow = table.NewRow();
if (row != null)
{
for (int j = row.FirstCellNum; j < cellCount; j++)
{
if (row.GetCell(j) != null)
dataRow[j] = GetCellValue(row.GetCell(j));
}
}
table.Rows.Add(dataRow);
}
return table;
}
}补充一个类
/// <summary>
/// 根据Excel列类型获取列的值
/// </summary>
/// <param name="cell">Excel列</param>
/// <returns></returns>
private static string GetCellValue(ICell cell)
{
if (cell == null)
return string.Empty;
switch (cell.CellType)
{
case CellType.BLANK:
return string.Empty;
case CellType.BOOLEAN:
return cell.BooleanCellValue.ToString();
case CellType.ERROR:
return cell.ErrorCellValue.ToString();
case CellType.NUMERIC:
case CellType.Unknown:
default:
return cell.ToString();//This is a trick to get the correct value of the cell. NumericCellValue will return a numeric value no matter the cell value is a date or a number
case CellType.STRING:
return cell.StringCellValue;
case CellType.FORMULA:
try
{
HSSFFormulaEvaluator e = new HSSFFormulaEvaluator(cell.Sheet.Workbook);
e.EvaluateInCell(cell);
return cell.ToString();
}
catch
{
return cell.NumericCellValue.ToString();
}
}
}得到DataTable后，就想怎么操作就怎么操作了
