Question

以下是我的LINQ

 IQueryable<ReportMapper> query;

                    query = (from c in entities.tDocumentStatus
                             join d in entities.tTOCStructures on c.DocumentId equals d.DocumentID
                             join e in entities.tUsers on d.LastUpdatedBy equals e.UserUID
                             orderby d.CreatedOn descending
                             where
                              (docMode <= 0 || docModes.Contains(c.StatusId)) &&
                              d.FolderType == 2 && d.isDeleted == false && d.ClientID == clientId &&
                              (EntityFunctions.TruncateTime(d.CreatedOn) >= startDate.Date && EntityFunctions.TruncateTime(d.CreatedOn) <= endDate.Date) 
                             select new ReportMapper()
                             {
                                 DocumentName = d.DocumentName,
                                 AssignedDate = c.AssignedDate==null? (EntityFunctions.TruncateTime(d.LastUpdatedOn)):  (EntityFunctions.TruncateTime(c.AssignedDate)),
                                 ReviewStatus = c.tStatu.StatusName,
                                 ActionPerformedBy = e.FirstName + " " + e.LastName
                             });

我需要将此数据导出为excel。我需要从指定日期删除完整的时间部分。

当我使用EntityFunctions.TruncateTime时，它会将时间截断为00:00:00

但我需要删除此部分。

我尝试了以下方法： -

(EntityFunctions.TruncateTime(d.LastUpdatedOn)).Value.Date
(EntityFunctions.TruncateTime(d.LastUpdatedOn).GetValueOrDefault().Date)
(EntityFunctions.TruncateTime(d.LastUpdatedOn)).ToString().Date

导出到Excel

   public void ExportToExcel()
    {
        ExcelPackage excel = new ExcelPackage();
            var worksheet = excel.Workbook.Worksheets.Add("Sheet1");
       fileName = "Document_Status_Report_" + DateTime.Now.ToString("yyyyMMdHHmmss") + ".xlsx";
                worksheet.Cells[1, 1].LoadFromCollection(data, true);
 using (MemoryStream swObj = new MemoryStream())
            {
                response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
                response.AddHeader("Content-Disposition", "attachment; filename=" + fileName + "");
                excel.SaveAs(swObj);
                swObj.WriteTo(response.OutputStream);
                return;
            }

    }

Answer 1

使用.Value.Date已经尝试过了。从不字符串。

您的问题不是时间部分（@PanagiotisKanavos解释），但格式应用于Excel中的单元格。只需调整此项即可仅显示日期部分。

Answer 2

DateTime总是有时间，你不能截断或删除Datetime的时间。如果你只想要日期，那么建议在ReportMapper类中添加新的字符串属性并仅指定日期string。如下面的代码所示，我已将“MM/dd/yyyy”格式的日期指定给AssignedDateString。

IQueryable<ReportMapper> query;

                    query = (from c in entities.tDocumentStatus
                             join d in entities.tTOCStructures on c.DocumentId equals d.DocumentID
                             join e in entities.tUsers on d.LastUpdatedBy equals e.UserUID
                             orderby d.CreatedOn descending
                             where
                              (docMode <= 0 || docModes.Contains(c.StatusId)) &&
                              d.FolderType == 2 && d.isDeleted == false && d.ClientID == clientId &&
                              (EntityFunctions.TruncateTime(d.CreatedOn) >= startDate.Date && EntityFunctions.TruncateTime(d.CreatedOn) <= endDate.Date) 
                             select new ReportMapper()
                             {
                                 DocumentName = d.DocumentName,
                                 AssignedDate = c.AssignedDate==null? (EntityFunctions.TruncateTime(d.LastUpdatedOn)):  (EntityFunctions.TruncateTime(c.AssignedDate)),
                                 ReviewStatus = c.tStatu.StatusName,
                                 ActionPerformedBy = e.FirstName + " " + e.LastName
                                 AssignedDateString= c.AssignedDate==null? (d.LastUpdatedOn.ToString("MM/dd/yyyy")):  (c.AssignedDate.ToString("MM/dd/yyyy")),
                             });

如何从LINQ中的Nullable <datetime>中删除时间部分

2 个答案: