Spire.xls -从流中返回文件以供客户端下载

Question

这就是我想要达到的目标。

我正在创建一个asp.net MVC应用程序。我的限制是不能以编程方式将任何内容保存到服务器的文件结构中，因此不能将其保存为主机上的物理文件，然后抓取它供客户端下载。

我正在将PDF加载到流中，从PDF中提取信息，动态构建excel文件，然后将该文件提供给客户端。我的密码在下面。

    // Loads the incoming PDF document to stream
    PdfDocument doc = new PdfDocument();
    using (var stream = model.BudgetPdfFile.OpenReadStream())
    {
        doc.LoadFromStream(stream);
    }
    
    var pageCount = doc.Pages.Count;
    var date = DateTime.Now.ToShortDateString().Replace("/", "-");
    
    // Extracts data from the PDF and separates it by NewLine
    SimpleTextExtractionStrategy strategy = new SimpleTextExtractionStrategy();
    StringBuilder allText = new StringBuilder();
    for (var i = 0; i < pageCount; i++)
    {
        allText.Append(doc.Pages[i].ExtractText(strategy));
    }
    var fullDocText = allText.ToString();
    List<string> linesList = new List<string>(fullDocText.Split(new[] { Environment.NewLine }, StringSplitOptions.None).ToList());
    
    // generates a comparison list for output data manipulation from static data
    var finalList = linesList.BuildFinalList(budgetItems);
    
    // creates a new Spire.PDF.Workbook for the final output excel file
    var result = new Workbook();
    
    // checks for whether the submitted budget is for a case in litigation or not and builds the correct excel workbook
    if (model.isTrial)
    {
        result = ExportExcelBudget.TrialBudgetSheet(model, finalList);
    }
    else
    {
        result = ExportExcelBudget.PreTrialBudgetSheet(model, finalList);
    }

当然，直到下面最后一节，一切都是完美的。但是，我不知道如何将工作簿加载到一个新的流中，然后返回该文件供下载。

    // saves the final workbook to a stream and offers it for download to the client 
    Stream outStream = new MemoryStream();
    var fileName = "Budget Report_" + model.ClaimNumber + "_" + date + ".xlsx";
    var contentType = "application/vnd.ms-excel";
    result.SaveToStream(outStream, Spire.Xls.FileFormat.Version2016);
    
    return File(outStream, contentType, fileName);

我搜索并尝试了多个不同的变体，但是当应用程序命中返回File()时，它返回一个null。

我已经通过了执行，结果似乎在那里，但它没有通过任何东西。如能对这里的问题提供任何帮助，我们将不胜感激。

Answer 1

    Stream outStream = new MemoryStream();
    var fileName = "Budget Report_" + model.ClaimNumber + "_" + date + ".xlsx";
    var contentType = "application/vnd.ms-excel";
    result.SaveToStream(outStream, Spire.Xls.FileFormat.Version2016);
    **outStream.Position = 0;**

    return File(outStream, contentType, fileName);

必须将流位置重置为0。现在工作得很好。