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：
1 <form class="layui-form" id="uploadForm"> 2 <input type="file" name="file" multiple value="选择" onchange="doUpload()" id="ajaxfile" /> 3 </form> 4 <script type="text/javascript"> 5 function doUpload() { 6 var formData = new FormData($("#uploadForm")[0]); 7 var url = '@Url.Action("ImportEquip", "FileUpload")'; 8 9 $.ajax({ 10 url: url, 11 type: 'POST', 12 data: formData, 13 async: false, 14 cache: false, 15 contentType: false, 16 processData: false, 17 success: function (returndata) { 18 layer.msg('上传成功！'); 19 location.reload(); 20 }, 21 error: function (returndata) { 22 console.log(returndata); 23 layer.msg('上传失败！'); 24 } 25 }); 26 } 27 </script>
后端页面：
1 private readonly IHostingEnvironment _hostingEnvironment; 2 private readonly GradeSettingsService _service; 3 public FileUploadController(IHostingEnvironment hostingEnvironment, GradeSettingsService service) 4 { 5 _hostingEnvironment = hostingEnvironment; 6 _service = service; 7 } 8 9 [AllowAnonymous] 10 [HttpPost] 11 public async Task<IActionResult> ImportEquip() 12 { 13 //获取Form提交的文件 14 var files = Request.Form.Files; 15 long size = files.Sum(f => f.Length); 16 string webRootPath = _hostingEnvironment.WebRootPath; //物理路径 17 string contentRootPath = _hostingEnvironment.ContentRootPath; 18 string showfilePath = ""; 19 bool IsSuccess = true; 20 foreach (var formFile in files) 21 { 22 if (formFile.Length > 0) 23 { 24 int count = formFile.FileName.Split('.').Length; 25 string fileExt = formFile.FileName.Split('.')[count - 1]; //文件扩展名，不含“.” 26 long fileSize = formFile.Length; //获得文件大小，以字节为单位 27 string newFileName = System.Guid.NewGuid().ToString() + "." + fileExt; //随机生成新的文件名 28 #region 文件夹不存在则创建 29 var filePath = webRootPath + "/upload"; 30 if (!Directory.Exists(filePath)) 31 { 32 Directory.CreateDirectory(filePath); 33 } 34 #endregion 35 #region 文件不存在则新建 36 filePath = webRootPath + "/upload/" + newFileName; 37 showfilePath = "upload/" + newFileName; 38 FileHelper.CreateFile(filePath); 39 #endregion 40 //把上传的图片复制到指定的文件中 41 using (var stream = new FileStream(filePath, FileMode.Create)) 42 { 43 await formFile.CopyToAsync(stream); 44 } 45 FileInfo file = new FileInfo(filePath); 46 using (ExcelPackage package = new ExcelPackage(file)) 47 { 48 StringBuilder sb = new StringBuilder(); 49 try 50 { 51 ExcelWorksheet worksheet = package.Workbook.Worksheets[1]; 52 List<Import_Equip> resultlist = worksheet.ConvertSheetToObjects<Import_Equip>().ToList(); 53 _service.ImportEquip(resultlist); 54 } 55 catch (Exception ex) 56 { 57 IsSuccess = false; 58 } 59 } 60 } 61 } 62 return Ok(new { count = files.Count, savepath = showfilePath, status = IsSuccess }); 63 }
附Epplus扩展类：
1 public static class EppLusExtensions 2 { 3 /// <summary> 4 /// 获取标签对应excel的Index 5 /// </summary> 6 /// <param name="ws"></param> 7 /// <param name="columnName"></param> 8 /// <returns></returns> 9 /// <exception cref="ArgumentNullException"></exception> 10 public static int GetColumnByName(this OfficeOpenXml.ExcelWorksheet ws, string columnName) 11 { 12 if (ws == null) throw new ArgumentNullException(nameof(ws)); 13 return ws.Cells["1:1"].First(c => c.Value.ToString() == columnName).Start.Column; 14 } 15 /// <summary> 16 /// 扩展方法 17 /// </summary> 18 /// <param name="worksheet"></param> 19 /// <typeparam name="T"></typeparam> 20 /// <returns></returns> 21 public static IEnumerable<T> ConvertSheetToObjects<T>(this OfficeOpenXml.ExcelWorksheet worksheet) where T : new() 22 { 23 Func<CustomAttributeData, bool> columnOnly = y => y.AttributeType == typeof(ExcelColumn); 24 var columns = typeof(T) 25 .GetProperties() 26 .Where(x => x.CustomAttributes.Any(columnOnly)) 27 .Select(p => new 28 { 29 Property = p, 30 Column = p.GetCustomAttributes<ExcelColumn>().First().ColumnName 31 }).ToList(); 32 var rows = worksheet.Cells 33 .Select(cell => cell.Start.Row) 34 .Distinct() 35 .OrderBy(x => x); 36 var collection = rows.Skip(1) 37 .Select(row => 38 { 39 var tnew = new T(); 40 columns.ForEach(col => 41 { 42 var val = worksheet.Cells[row, GetColumnByName(worksheet, col.Column)]; 43 if (val.Value == null) 44 { 45 col.Property.SetValue(tnew, null); 46 return; 47 } 48 49 if (col.Property.PropertyType == typeof(int)) 50 { 51 col.Property.SetValue(tnew, val.GetValue<int>()); 52 return; 53 } 54 55 if (col.Property.PropertyType == typeof(double)) 56 { 57 col.Property.SetValue(tnew, val.GetValue<double>()); 58 return; 59 } 60 61 if (col.Property.PropertyType == typeof(DateTime?)) 62 { 63 col.Property.SetValue(tnew, val.GetValue<DateTime?>()); 64 return; 65 } 66 67 if (col.Property.PropertyType == typeof(DateTime)) 68 { 69 col.Property.SetValue(tnew, val.GetValue<DateTime>()); 70 return; 71 } 72 73 if (col.Property.PropertyType == typeof(bool)) 74 { 75 col.Property.SetValue(tnew, val.GetValue<bool>()); 76 return; 77 } 78 col.Property.SetValue(tnew, val.GetValue<string>()); 79 }); 80 return tnew; 81 }); 82 return collection; 83 } 84 }
2.Excel导出
前端：
1 <a asp-action="ExportSun" class="layui-btn layui-btn-sm" id="btnexcel">导出</a>
后端：
1 public IActionResult ExportSun() 2 { 3 string sWebRootFolder = _hostingEnvironment.WebRootPath; 4 //获取数据集 5 var datalist = _service.GetExportSunData(); 6 string sFileName = $"{Guid.NewGuid()}.xlsx"; 7 FileInfo file = new FileInfo(Path.Combine(sWebRootFolder, sFileName)); //Path.Combine把多个字符串组成一个路径 8 using (ExcelPackage package = new ExcelPackage(file)) //ExcelPackage 操作excel的主要对象 9 { 10 // 添加worksheet 11 ExcelWorksheet worksheet = package.Workbook.Worksheets.Add("aspnetcore"); 12 //添加头 13 worksheet.Cells[1, 1].Value = "班级ID"; 14 worksheet.Cells[1, 2].Value = "学校名称"; 15 worksheet.Cells[1, 3].Value = "年级类型"; 16 17 int Count = 2; 18 foreach (var model in datalist) 19 { 20 worksheet.Cells["A" + Count.ToString()].Value = model.ClassID; 21 worksheet.Cells["B" + Count.ToString()].Value = model.DeptName; 22 worksheet.Cells["C" + Count.ToString()].Value = model.GradeTypeName; 23 24 Count++; 25 } 26 package.Save(); 27 } 28 return File(sFileName, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"); 29 }
以上仅用于学习和记录