.Net Core Excel导出和导入

项目中Excel导入和导出算是常用的功能，以下记录和总结:

1.Excel导入

导入功能从之前的附件上传功能（ https://www.cnblogs.com/ywkcode/p/11703523.html）进行了修改，原理是通过CopyToAsync生成Excel文件，通过EPPlus.Core操作Excel文件，读取文件内容，解析成集合进行业务操作，使用前需要引用：EPPlus.Core

 

前端页面：

<form class="layui-form" id="uploadForm">  
   <input type="file" name="file" multiple value="选择" onchange="doUpload()" id="ajaxfile"  />
</form>
<script type="text/javascript">
  function doUpload() {
              var formData = new FormData($("#uploadForm")[0]);
              var  url = '@Url.Action("ImportEquip", "FileUpload")';
              
              $.ajax({
                url: url,
                type: 'POST',
                data: formData,
                async: false,
                cache: false,
                contentType: false,
                processData: false,
                success: function (returndata) {
                    layer.msg('上传成功！');
                    location.reload();
                },
                error: function (returndata) {
                    console.log(returndata);
                    layer.msg('上传失败！');
                }
            });
        }
</script>

后端页面：

  private readonly IHostingEnvironment _hostingEnvironment;
        private readonly GradeSettingsService _service;
        public FileUploadController(IHostingEnvironment hostingEnvironment,  GradeSettingsService  service)
        {
            _hostingEnvironment = hostingEnvironment;
            _service = service;
        }        

        [AllowAnonymous]
        [HttpPost]
        public async Task<IActionResult> ImportEquip()
        {
            //获取Form提交的文件
            var files = Request.Form.Files;
            long size = files.Sum(f => f.Length);
            string webRootPath = _hostingEnvironment.WebRootPath; //物理路径
            string contentRootPath = _hostingEnvironment.ContentRootPath;
            string showfilePath = "";
            bool IsSuccess = true;
            foreach (var formFile in files)
            {
                if (formFile.Length > 0)
                {
                    int count = formFile.FileName.Split('.').Length;
                    string fileExt = formFile.FileName.Split('.')[count - 1]; //文件扩展名，不含“.”
                    long fileSize = formFile.Length; //获得文件大小，以字节为单位
                    string newFileName = System.Guid.NewGuid().ToString() + "." + fileExt;  //随机生成新的文件名
                    #region 文件夹不存在则创建
                    var filePath = webRootPath + "/upload";
                    if (!Directory.Exists(filePath))
                    {
                        Directory.CreateDirectory(filePath);
                    }
                    #endregion
                    #region 文件不存在则新建
                    filePath = webRootPath + "/upload/" + newFileName;
                    showfilePath = "upload/" + newFileName;
                    FileHelper.CreateFile(filePath);
                    #endregion
                    //把上传的图片复制到指定的文件中
                    using (var stream = new FileStream(filePath, FileMode.Create))
                    {
                        await formFile.CopyToAsync(stream);
                    }
                    FileInfo file = new FileInfo(filePath);
                    using (ExcelPackage package = new ExcelPackage(file))
                    {
                        StringBuilder sb = new StringBuilder();
                        try
                        {
                            ExcelWorksheet worksheet = package.Workbook.Worksheets[1];
                            List<Import_Equip> resultlist =  worksheet.ConvertSheetToObjects<Import_Equip>().ToList();
                            _service.ImportEquip(resultlist);
                        }
                        catch (Exception ex)
                        {
                            IsSuccess = false;
                        }
                    }
                }
            }
            return Ok(new { count = files.Count, savepath = showfilePath, status =  IsSuccess });
        }

附Epplus扩展类：

public static class EppLusExtensions
    {
        /// <summary>
        /// 获取标签对应excel的Index
        /// </summary>
        /// <param name="ws"></param>
        /// <param name="columnName"></param>
        /// <returns></returns>
        /// <exception cref="ArgumentNullException"></exception>
        public static int GetColumnByName(this OfficeOpenXml.ExcelWorksheet ws, string  columnName)
        {
            if (ws == null) throw new ArgumentNullException(nameof(ws));
            return ws.Cells["1:1"].First(c => c.Value.ToString() ==  columnName).Start.Column;
        }
        /// <summary>
        /// 扩展方法
        /// </summary>
        /// <param name="worksheet"></param>
        /// <typeparam name="T"></typeparam>
        /// <returns></returns>
        public static IEnumerable<T> ConvertSheetToObjects<T>(this  OfficeOpenXml.ExcelWorksheet worksheet) where T : new()
        {
            Func<CustomAttributeData, bool> columnOnly = y => y.AttributeType ==  typeof(ExcelColumn);
            var columns = typeof(T)
                .GetProperties()
                .Where(x => x.CustomAttributes.Any(columnOnly))
                .Select(p => new
                {
                    Property = p,
                    Column = p.GetCustomAttributes<ExcelColumn>().First().ColumnName
                }).ToList();
            var rows = worksheet.Cells
                .Select(cell => cell.Start.Row)
                .Distinct()
                .OrderBy(x => x);
            var collection = rows.Skip(1)
                .Select(row =>
                {
                    var tnew = new T();
                    columns.ForEach(col =>
                    {
                        var val = worksheet.Cells[row, GetColumnByName(worksheet,  col.Column)];
                        if (val.Value == null)
                        {
                            col.Property.SetValue(tnew, null);
                            return;
                        }
                      
                        if (col.Property.PropertyType == typeof(int))
                        {
                            col.Property.SetValue(tnew, val.GetValue<int>());
                            return;
                        }
                        
                        if (col.Property.PropertyType == typeof(double))
                        {
                            col.Property.SetValue(tnew, val.GetValue<double>());
                            return;
                        }
                     
                        if (col.Property.PropertyType == typeof(DateTime?))
                        {
                            col.Property.SetValue(tnew, val.GetValue<DateTime?>());
                            return;
                        }
                     
                        if (col.Property.PropertyType == typeof(DateTime))
                        {
                            col.Property.SetValue(tnew, val.GetValue<DateTime>());
                            return;
                        }
                      
                        if (col.Property.PropertyType == typeof(bool))
                        {
                            col.Property.SetValue(tnew, val.GetValue<bool>());
                            return;
                        }
                        col.Property.SetValue(tnew, val.GetValue<string>());
                    });
                    return tnew;
                });
            return collection;
        }
    }

2.Excel导出

前端：

  <a asp-action="ExportSun"  class="layui-btn layui-btn-sm" id="btnexcel">导出</a>

后端：

   public IActionResult ExportSun()
        {
            string sWebRootFolder = _hostingEnvironment.WebRootPath;
            //获取数据集
            var datalist = _service.GetExportSunData();
            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 = "班级ID";
                worksheet.Cells[1, 2].Value = "学校名称";
                worksheet.Cells[1, 3].Value = "年级类型"; 
                 
                int Count = 2;
                foreach (var model in datalist)
                {
                    worksheet.Cells["A" + Count.ToString()].Value = model.ClassID;
                    worksheet.Cells["B" + Count.ToString()].Value = model.DeptName;
                    worksheet.Cells["C" + Count.ToString()].Value = model.GradeTypeName;
                    
                    Count++;
                }
                package.Save();
            }
            return File(sFileName,  "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        }

 

参考文档： https://www.cnblogs.com/Vincent-yuan/p/10909307.html

 

以上仅用于学习和记录