mvc手把手教你写excel导入[mvc+三层，没用EF]

<div class="filebtn"> 
                @using (Html.BeginForm("importexcel", "foot", FormMethod.Post, new { enctype = "multipart/form-data" }))
                    {
                        <samp>请选择要上传的Excel文件：</samp>
                        <span  id="txt_Path"></span>
                        <strong>选择文件<input name="file" type="file" id="file" /></strong>@*
                        @Html.AntiForgeryToken()  //防止跨站请求伪造(CSRF:Cross-site request forgery)攻击
                     *@<input type="submit" id="ButtonUpload" value="提交"   class="offer"/> 
                    }
            </div>

public class footController : Controller
    {
        //
        // GET: /foot/
        private static readonly String Folder = "/files";
        public ActionResult excel()
        {
            return View();
        }

        /// 导入excel文档
        public ActionResult importexcel()
        {
            //1.接收客户端传过来的数据
            HttpPostedFileBase file = Request.Files["file"];
            if (file == null || file.ContentLength <= 0)
            {
                return Json("请选择要上传的Excel文件", JsonRequestBehavior.AllowGet);
            }
           //string filepath =  Server.MapPath(Folder);
           //if (!Directory.Exists(filepath))
           //{
           //    Directory.CreateDirectory(filepath);
           //}
           //var fileName = Path.Combine(filepath, Path.GetFileName(file.FileName));
           // file.SaveAs(fileName);
            //获取一个streamfile对象，该对象指向一个上传文件，准备读取改文件的内容
            Stream streamfile = file.InputStream;
            DataTable dt = new DataTable();
            string FinName = Path.GetExtension(file.FileName);
            if (FinName != ".xls" && FinName != ".xlsx")
            {
                return Json("只能上传Excel文档",JsonRequestBehavior.AllowGet);
            }
            else
            {
                try
                {
                    if (FinName == ".xls")
                    {
                        //创建一个webbook，对应一个Excel文件(用于xls文件导入类)
                        HSSFWorkbook hssfworkbook = new HSSFWorkbook(streamfile);
                        dt = excelDAL.ImExport(dt, hssfworkbook);
                    }
                    else
                    {
                        XSSFWorkbook hssfworkbook = new XSSFWorkbook(streamfile);
                        dt = excelDAL.ImExport(dt, hssfworkbook);
                    }
                    return Json("",JsonRequestBehavior.AllowGet);
                }
                catch(Exception ex)
                {
                    return Json("导入失败 ！"+ex.Message, JsonRequestBehavior.AllowGet);
                }
        }
            
        }

}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using NPOI;
using NPOI.SS.UserModel;
using NPOI.HSSF.UserModel;
using System.Data;
using NPOI.XSSF.UserModel;

namespace GJL.Compoent
{
   public class excelDAL
    {
       ///<summary>
        /// #region 两种不同版本的操作excel
        /// 扩展名*.xlsx
       /// </summary>
       public static DataTable ImExport(DataTable dt, XSSFWorkbook  hssfworkbook)
       {
           NPOI.SS.UserModel.ISheet sheet = hssfworkbook.GetSheetAt(0);
           System.Collections.IEnumerator rows = sheet.GetRowEnumerator();
           for (int j = 0; j < (sheet.GetRow(0).LastCellNum); j++)
           {
               dt.Columns.Add(sheet.GetRow(0).Cells[j].ToString());
           }
           while (rows.MoveNext())
           {
               XSSFRow row = (XSSFRow)rows.Current;
               DataRow dr = dt.NewRow();
               for (int i = 0; i < row.LastCellNum; i++)
               {
                   NPOI.SS.UserModel.ICell cell = row.GetCell(i);
                   if (cell == null)
                   {
                       dr[i] = null;
                   }
                   else
                   {
                       dr[i] = cell.ToString();
                   }
               }
               dt.Rows.Add(dr);
           }
           dt.Rows.RemoveAt(0);
           if (dt!=null && dt.Rows.Count != 0)
           {
               for (int i = 0; i < dt.Rows.Count; i++)
               {
                   string categary = dt.Rows[i]["页面"].ToString();
                   string fcategary = dt.Rows[i]["分类"].ToString();
                   string fTitle = dt.Rows[i]["标题"].ToString();
                   string fUrl = dt.Rows[i]["链接"].ToString();
                   FooterDAL.Addfoot(categary, fcategary, fTitle, fUrl);
               }
           }
           return dt;
       }

        #region 两种不同版本的操作excel
        ///<summary>
        /// 扩展名*.xls
        /// </summary>
       public static DataTable ImExport(DataTable dt, HSSFWorkbook hssfworkbook)
       {
           // 在webbook中添加一个sheet,对应Excel文件中的sheet,取出第一个工作表，索引是0 
           NPOI.SS.UserModel.ISheet sheet = hssfworkbook.GetSheetAt(0);
           System.Collections.IEnumerator rows = sheet.GetRowEnumerator();
           for (int j = 0; j < (sheet.GetRow(0).LastCellNum); j++)
           {
               dt.Columns.Add(sheet.GetRow(0).Cells[j].ToString());
           }
           while (rows.MoveNext())
           {
               HSSFRow row = (HSSFRow)rows.Current;
               DataRow dr = dt.NewRow();
               for (int i = 0; i < row.LastCellNum; i++)
               {
                   NPOI.SS.UserModel.ICell cell = row.GetCell(i);
                   if (cell == null)
                   {
                       dr[i] = null;
                   }
                   else 
                   {
                       dr[i] = cell.ToString();
                   }
               }
               dt.Rows.Add(dr);
           }
           dt.Rows.RemoveAt(0);
           if (dt != null && dt.Rows.Count != 0)
           {
               for (int i = 0; i < dt.Rows.Count; i++)
               {
                   string categary = dt.Rows[i]["页面"].ToString();
                   string fcategary = dt.Rows[i]["分类"].ToString();
                   string fTitle = dt.Rows[i]["标题"].ToString();
                   string fUrl = dt.Rows[i]["链接"].ToString();
                   FooterDAL.Addfoot(categary, fcategary, fTitle, fUrl);
               }

           }
           return dt;
       }
        #endregion
    }
}

 public static partial class FooterDAL
    {
        /// <summary>
        /// 添加
        /// </summary>
        /// <param name="id"></param>
        /// <param name="catgary"></param>
        /// <param name="fcatgary"></param>
        /// <param name="fTitle"></param>
        /// <param name="fUrl"></param>
        /// <returns></returns>
        public static int  Addfoot(string categary, string fcategary, string fTitle, string fUrl)
        {
            string sql = string.Format("insert into Foot (categary,fcategary,fTitle,fUrl)values(@categary,@fcategary,@fTitle,@fUrl)");
            SqlParameter[] parm = 
                { 
                     new SqlParameter("@categary",categary)
                    ,new SqlParameter("@fcategary",fcategary)
                    ,new SqlParameter("@fTitle",fTitle)
                    ,new SqlParameter("@fUrl",fUrl)
                };
            return new DBHelperSQL<Foot>(CommonTool.dbname).ExcuteSql(sql,parm);   
        }
}