在MVC和.NET中使用iText 7生成要下载的PDF [英] Generate PDF for Download using iText 7 in MVC and .NET

问题描述

我一直在尝试获取MVC应用程序以生成PDF(填充数据)并提示将其下载给用户.我已经设置了一个测试方法来查看它的完成方式，并且我试图在内存中创建文档，因为我知道浏览器并不总是知道如果只将字节流传递给它，该怎么办.

这是我使用的方法:

    //Test Report
    public ActionResult Report()
    {
        MemoryStream stream = new MemoryStream();        
        PdfWriter wri = new PdfWriter(stream);
        PdfDocument pdf = new PdfDocument(wri);
        Document doc = new Document(pdf);
        doc.Add(new Paragraph("Hello World!"));
        doc.Close();

        return new FileStreamResult(stream, "application/pdf");
     }

每次尝试加载Report()方法时，都会收到一条错误消息，指出该流已关闭，因此无法访问.我研究了为什么这样做的几种不同解释，但它们似乎都是针对iTextSharp和iText 5的，因此解决方案不起作用.

这是我在做错什么吗?

解决方案

尝试处置任何IDisposable对象并返回原始数组

public ActionResult Report()
{ 
  byte[] pdfBytes;
  using (var stream = new MemoryStream())
  using (var wri = new PdfWriter(stream))
  using (var pdf = new PdfDocument(wri))
  using (var doc = new Document(pdf))
  {
    doc.Add(new Paragraph("Hello World!"));
    doc.Flush();
    pdfBytes = stream.ToArray();
  }
  return new FileContentResult(pdfBytes, "application/pdf");
 }

I have been trying to get an MVC application to generate a PDF(populated with data) and prompt to download it to the user. I've setup a test method just to see how it would be done, and I'm trying to create the document in memory since I know browsers don't always know what to do if you just pass it a byte stream.

Here is the method I'm using:

    //Test Report
    public ActionResult Report()
    {
        MemoryStream stream = new MemoryStream();        
        PdfWriter wri = new PdfWriter(stream);
        PdfDocument pdf = new PdfDocument(wri);
        Document doc = new Document(pdf);
        doc.Add(new Paragraph("Hello World!"));
        doc.Close();

        return new FileStreamResult(stream, "application/pdf");
     }

Every time I attempt to load the Report() method, I get an error saying that the stream cannot be accessed because it's closed. I've looked into a few different explanations into why this is, but all of them seem to be for iTextSharp and iText 5, so the solutions don't work.

What am I doing wrong, here?

解决方案

try to dispose any IDisposable object and return a raw array

public ActionResult Report()
{ 
  byte[] pdfBytes;
  using (var stream = new MemoryStream())
  using (var wri = new PdfWriter(stream))
  using (var pdf = new PdfDocument(wri))
  using (var doc = new Document(pdf))
  {
    doc.Add(new Paragraph("Hello World!"));
    doc.Flush();
    pdfBytes = stream.ToArray();
  }
  return new FileContentResult(pdfBytes, "application/pdf");
 }

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