asp.net core web的导入导出excel功能

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using OfficeOpenXml;

namespace EPPlusDemo.Controllers
{
    public class XlsxController : Controller
    {
        //用来获取路径相关
        private IHostingEnvironment _hostingEnvironment;

        public XlsxController(IHostingEnvironment hostingEnvironment)
        {
            _hostingEnvironment = hostingEnvironment;
        }
        public IActionResult Index()
        {
            return View();
        }

        /// <summary>
        /// excel导出功能
        /// </summary>
        /// <returns></returns>
        public IActionResult Export()
        {
            string sWebRootFolder = _hostingEnvironment.WebRootPath;
            string sFileName = $"{Guid.NewGuid()}.xlsx";
            FileInfo file = new FileInfo(Path.Combine(sWebRootFolder, sFileName));  //Path.Combine把多个字符串组成一个路径
            using (ExcelPackage package = new ExcelPackage(file))   //ExcelPackage 操作excel的主要对象
            {
                // 添加worksheet
                ExcelWorksheet worksheet = package.Workbook.Worksheets.Add("aspnetcore");
                //添加头
                worksheet.Cells[1, 1].Value = "ID";
                worksheet.Cells[1, 2].Value = "Name";
                worksheet.Cells[1, 3].Value = "Url";
                //添加值
                worksheet.Cells["A2"].Value = 1000;
                worksheet.Cells["B2"].Value = "baidu";
                worksheet.Cells["C2"].Value = "https://www.baidu.com/";

                worksheet.Cells["A3"].Value = 1001;
                worksheet.Cells["B3"].Value = "博客园";
                worksheet.Cells["C3"].Value = "https://www.cnblogs.com/";
                worksheet.Cells["C3"].Style.Font.Bold = true;

                package.Save();
            }
            return File(sFileName, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        }

　　　　　//导入功能
        [HttpPost]
        public IActionResult Import(IFormFile excelfile)
        {
            string sWebRootFolder = _hostingEnvironment.WebRootPath;
            string sFileName = $"{Guid.NewGuid()}.xlsx";
            FileInfo file = new FileInfo(Path.Combine(sWebRootFolder, sFileName));
            try
            {
                //把excelfile中的数据复制到file中
                using (FileStream fs = new FileStream(file.ToString(), FileMode.Create)) //初始化一个指定路径和创建模式的FileStream
                {
                    excelfile.CopyTo(fs);
                    fs.Flush();  //清空stream的缓存，并且把缓存中的数据输出到file
                }

                using (ExcelPackage package = new ExcelPackage(file))
                {
                    StringBuilder sb = new StringBuilder();
                    ExcelWorksheet worksheet = package.Workbook.Worksheets[1];
                    int rowCount = worksheet.Dimension.Rows;
                    int ColCount = worksheet.Dimension.Columns;
                    
                    for (int row = 1; row <= rowCount; row++)
                    {
                        for (int col = 1; col <= ColCount; col++)
                        {
                            //sb.Append(worksheet.Cells[row, col].Value.ToString() + "\t"); //这种写法遇到为null的为报错
                            sb.Append(worksheet.Cells[row, col].Value + "\t");
                        }
                        sb.Append(Environment.NewLine);
                    }
                    return Content(sb.ToString());
                }
            }
            catch (Exception ex)
            {
                return Content(ex.Message);
            }
        }


    }

@{
    ViewData["Title"] = "Index";
}


<h2>ASP.NET Core 导入导出Excel xlsx 文件</h2>

<a asp-action="Export">导出Excel</a>
<hr />

<!--导入-->
<form enctype="multipart/form-data" method="post" asp-action="Import">
    <input type="file" name="excelfile" />
    <input type="submit" value="上传" />
</form>