Display ASP.NET generated pdf byte[] to web page without saving the file

问题

I'm using iTextSharp for generating a pdf. I can save the PDF file from the PDF byte[].

byte[] outputPDF = cnt.CreateBreakPDF();
File.WriteAllBytes(pdfOutPutPath, outputPDF);

What is the best way to display the output byte[] to a web page?

I want to show the PDF inside a div in my page. Not the PDF as a full response.

I've seen answers for MVC, but I'm using ASP.NET Web Application.

Is there a better way than using HTTP handlers to do so? I don't want to send all the details for creating PDF as query string.

回答1:

I tried this in jsFiddle, and it works well in Chrome & FF, need to check on other browsers as well.

Convert the byte[] to Base64 using,

string base64PDF = System.Convert.ToBase64String(outputPDF, 0, outputPDF.Length);

All I had to do is specify the MIME type as data:application/pdf;base64, in the source and give the Base64 version of the PDF.

<object data="data:application/pdf;base64, JVBERi0xLjQKJeLjz9MKMyA..." type="application/pdf" width="160px">
    <embed src="data:application/pdf;base64, JVBERi0xLjQKJeLjz9MKMyA..." type="application/pdf" />
</object>

I couldn't be able to hide the top toolbar which appears in FF by appending #toolbar=0&navpanes=0&statusbar=0.

IE8 needs a saved pdf file to be displayed.

回答2:

Try this

Response.ContentType = "application/pdf";
Response.AddHeader("content-length", outputPDF.Length.ToString());
Response.BinaryWrite(outputPDF);

回答3:

I have being using Convert.ToBase64String(content) for some projects without any issue, until today with a 18 page file at about 1 MB. The error from Chrome's console is Failed to load resource: net::ERR_INVALID_URL. I guess it's because of the string size?!

I ended up using web api and just return it as FileStreamResult instead of Base64 string.

var stream = new MemoryStream();
await stream.WriteAsync(content, 0, content.Length);
stream.Position = 0;
return new FileStreamResult(stream, "application/pdf");

Update: It's basically the same to display it on a razor page. I just copied my code for retrieving fax content using RingCentral here. And better yet, just use FileContentResult as you already have the byte[].

public async Task<IActionResult> OnGet(string messageId)
{
    try
    {
        using (var rc = new RingCentral.RestClient(setting.ClientId, setting.ClientSecret, setting.Production, "Fax"))
        {
            await rc.Authorize(setting.UserName, setting.Extension, setting.Password);
            var extension = rc.Restapi().Account().Extension();
            var outputPDF = await extension.MessageStore(messageId).Content(messageId).Get();

            return new FileContentResult(outputPDF, "application/pdf");
        }
        return Page();
    }
    catch (Exception ex)
    {
        _logger.Error(ex.Message);
        throw;
    }
}

回答4:

Would something like this work?

<div>
<object data="myPDF.pdf" type="application/pdf" width="200" height="500">
alt : <a href="myPDF.pdf">myPDF.pdf</a>
</object>
</div>

You would just need to pass your pdf into the object data source.

来源：https://stackoverflow.com/questions/17108278/display-asp-net-generated-pdf-byte-to-web-page-without-saving-the-file

标签

ASP.NET

pdf

itextsharp

mime