OpenXML Excel 文档的 MemoryStream 为空

Question

我通常会使用 ClosedXML 生成 Excel 文件。核心项目迫使我只使用 OpenXML。

将下载生成的 Excel 文件。

我遇到了一个问题，即提供给 SpreadsheetDocument 的内存流是空的。

我尝试了多种方法来生成流。下面的代码代表了一个精简版本，只创建了基本要素。同样，内存流的长度为 0。

我知道我应该使用 using() 等。这只是简化代码以尝试让它工作。

生成excel的代码；这是来自 File 对象的构造函数。 AsMemoryStream 是一个属性声明为 public MemoryStream AsMemoryStream { get; private set; }

public File(IList<T> items)
        {
            if (!items.Any())
                throw new InvalidOperationException("items cannot be empty");


            MemoryStream documentStream = new MemoryStream();
            SpreadsheetDocument document = SpreadsheetDocument.Create(documentStream, DocumentFormat.OpenXml.SpreadsheetDocumentType.Workbook);

            WorkbookPart workbookPart = document.AddWorkbookPart();
            workbookPart.Workbook = new Workbook();

            WorksheetPart worksheetPart = workbookPart.AddNewPart<WorksheetPart>();
            worksheetPart.Worksheet = new Worksheet();

            Sheets sheets = workbookPart.Workbook.AppendChild(new Sheets());
            Sheet sheet = new Sheet { Id = workbookPart.GetIdOfPart(worksheetPart), SheetId = 1, Name = "Export" };

            sheets.Append(sheet);

            // have tried various Save() calls
            // worksheetPart.Worksheet.Save(); 
            // workbookPart.Workbook.Save();

            AsMemoryStream = new MemoryStream();
            documentStream.CopyTo(AsMemoryStream);
}

我在控制器中将文件下载为：

public IActionResult TransactionDetails(int transactionId)
        {

            IList<Partner> details = _dataService.GetTransactionPartners(transactionId).Result;
            MemoryStream excelStream = _excelRepository.TransactionDetailExcel(details).AsMemoryStream;
            ContentDisposition contentDisposition = new ContentDisposition
            {
                FileName = "transactionDetails.xlsx",
                Inline = false
            };
            Response.Headers.Add("content-disposition", contentDisposition.ToString());
            return File(excelStream.ToArray(), "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        }

文件已下载，但长度为 0 字节。与正在使用的任何内存流一样。

谁能指出我正确的方向？

Answer 1

SpreadSheetDocument 跟踪需要写入流的内容。它仅在调用 Close 或 Dispose 时这样做。在那一刻之前，它不会创建任何 OpenXmlPackage，因为它无法确定文档是否完整。

修复代码的方法如下：

MemoryStream documentStream = new MemoryStream();
using(SpreadsheetDocument document = SpreadsheetDocument.Create(documentStream, DocumentFormat.OpenXml.SpreadsheetDocumentType.Workbook))
{
    WorkbookPart workbookPart = document.AddWorkbookPart();

    workbookPart.Workbook = new Workbook();

    WorksheetPart worksheetPart = workbookPart.AddNewPart<WorksheetPart>();
    worksheetPart.Worksheet = new Worksheet();

    Sheets sheets = workbookPart.Workbook.AppendChild(new Sheets());
    Sheet sheet = new Sheet { Id = workbookPart.GetIdOfPart(worksheetPart), SheetId = 1, Name = "Export" };

    sheets.Append(sheet);
    document.Close();
}

// the stream is complete here
AsMemoryStream = new MemoryStream();
documentStream.CopyTo(AsMemoryStream);

OpenXML Excel 文档的 MemoryStream 为空

MemoryStream is empty for an OpenXML Excel document

c#

excel

openxml

openxml-sdk

asp.net-core