c# - iTextSharp 文件操作和显示到 FileStreamResults

Question

我正在尝试使用 iTextSharp 打开 PDF 文件，将数据集添加到文件以预填充数据，然后将其保存到流中以便我可以将其显示给用户。我不想将它保存在本地文件中。我不断收到错误消息“无法访问已关闭的流”。我不知道哪个流是错误的。

这是我的代码:

public FileStreamResult PushDataIntoPDFStream(string filename)
{     
     var reader = new PdfReader(Path.Combine(Server.MapPath(path), filename));
     var xml = @"<?xml version=""1.0"" encoding=""UTF-8""?>
          <form1>  
             <firstName>test</firstName>
             <lastName>user</lastName>
             <driveCar>0</driveCar>
             <gender>1</gender>
             <birthdate>2011-08-12</birthdate>
             <numPets>4</numPets>
          </form1>";

     using (var outstream = new MemoryStream())
     { 
          using (var stamper = new PdfStamper(reader, outstream))
          {
               var bytes = System.Text.Encoding.UTF8.GetBytes(xml);
               using (var ms = new MemoryStream(bytes))
               {
                    stamper.AcroFields.Xfa.FillXfaForm(ms);
               }
          }

          return new FileStreamResult(outstream, "application/pdf")
          {
                FileDownloadName = "file.pdf";
          };
     }      
  }

Answer 1

PdfStamper 在其内部输出流上有一个 .CloseStream 属性；尝试将其设置为 false:

using (var stamper = new PdfStamper(reader, outstream))
{
    stamper.Writer.CloseStream = false;