使用NPOI库导入导出EXCEL

一、EXCEL 导入（Excel 导入导出实际项目中会被封装成**Helper 本示例只对简单功能做演示）

NPOI 包引用

视图view

@{ViewBag.Title = "NPOIExcel";
}<h2>NPOIExcel</h2>
<form action="@Url.Action("NPOIInport", "Home")" method="post" enctype="multipart/form-data"><input type="file" name="Importexcelfile" /><button type="submit">提交</button>
</form>//enctype="multipart/form-data"  上传文件时form 表单必加

Action

命名空间引用

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

 /// <summary>/// NPOI 导入excel/// </summary>/// <returns></returns>
        [HttpPost]public ActionResult NPOIInport(){bool isok = false;string msg = string.Empty;var file = Request.Files["Importexcelfile"];//接收的文件对象var filename = SaveUploadExcel(file);//将文件保存至某一路径下 并形成新的文件名称var filePath=System.Configuration.ConfigurationManager.AppSettings["Upload"] + @"\excel\" + filename;//新路径IWorkbook workbook = null; //定义工作簿接口ISheet sheet=null;//定义sheet表DataTable data = new DataTable();FileStream filestream = new FileStream(filePath, FileMode.Open, FileAccess.Read);if (file.ContentLength>0){if (filePath.IndexOf(".xlsx") > 0){workbook = new XSSFWorkbook(filestream);//.xlsx 文件
                }else{workbook = new HSSFWorkbook(filestream);//.xls文件
                }sheet = workbook.GetSheetAt(0);//默认第一个sheet sheet 下标//sheet = workbook.GetSheet("sheet的名字");//获取想要查询sheet的名字if (sheet!=null){for (int i = 0; i < sheet.LastRowNum; i++){IRow row = sheet.GetRow(i);//获取第一行 一般都是表头var firstvalue = row.GetCell(0);//第一行的第一列var secondvalue = row.GetCell(1);}//常见读取excel 已经够用  实际项目中会遇到 再次封装数据形成table  一般这个帮助类会叫**HelperIRow firstrow = sheet.GetRow(0);int cellcount = firstrow.LastCellNum;//总列数for (int i = firstrow.FirstCellNum; i < cellcount; i++){ICell icell = firstrow.GetCell(i);if (icell!=null){string cellvalue = icell.StringCellValue;//获取当前单元格的valueDataColumn column = new DataColumn(cellvalue);data.Columns.Add(column);//添加表头
                        }}int startrow = sheet.FirstRowNum + 1;for (int i = startrow; i < sheet.LastRowNum; i++){IRow row = sheet.GetRow(i);if (row!=null){DataRow datarow = data.NewRow();for (int j = row.FirstCellNum; j < cellcount; j++){if (row.GetCell(j)!=null){datarow[j] = row.GetCell(j).ToString();}}data.Rows.Add(datarow);}}//return data;
                }}return Json(new { Isok = isok, Msg = msg });}public static string SaveUploadExcel(HttpPostedFileBase fileexcel){string filename = fileexcel.FileName;string extension = Path.GetExtension(filename);int filesize = fileexcel.ContentLength;if (filesize>int.Parse(System.Configuration.ConfigurationManager.AppSettings["UploadFileSize"])){return "文件超过上限";}string dirPath = System.Configuration.ConfigurationManager.AppSettings["Upload"] + @"\excel\";//生成新的文件名string newFileName = string.Format("{0}{1}", DateTime.Now.ToString("yyMMddHHmmssfffffff"), extension);if (!Directory.Exists(dirPath))Directory.CreateDirectory(dirPath);fileexcel.SaveAs(dirPath + newFileName);//返回新生成的文件名称return newFileName;}