How to generate PDF with iTextSharp and show/download it from web browser within a WebApi2 C#/.NET project?

Question

This one is driving me mad. I'm trying to implement this example, which is working if you download the project, but I have a WebApi2 app, not the classic aspx, so I have problems with Response (The name 'Response' does not exist in the current context).

var document = new Document(PageSize.A4, 50, 50, 25, 25);

var output = new MemoryStream();
var writer = PdfWriter.GetInstance(document, output);

document.Open();

document.Add(new Paragraph("Hello World"));

document.Close();

Response.ContentType = "application/pdf";
Response.AddHeader("Content-Disposition", string.Format("attachment;filename=testDoc.pdf", "some string"));
Response.BinaryWrite(output.ToArray());

I tried several things like adding HttpContext.Current to the Response like this:

HttpContext.Current.Response.ContentType = "application/pdf";
HttpContext.Current.Response.AddHeader("Content-Disposition", string.Format("attachment;filename=testDoc.pdf", "some string"));
HttpContext.Current.Response.BinaryWrite(output.ToArray());

But there's no way I can make the .pdf document to show on/download from the browser.

What am I to do here?

From what context are you doing this? You don't need the Response object to return a file from a Web API controller. See for example [Returning binary file from controller in ASP.NET Web API](https://stackoverflow.com/questions/9541351/returning-binary-file-from-controller-in-asp-net-web-api). — CodeCaster, Jun 26 '17 at 10:58
if your method signature is like this `public HttpResponseMessage YourMethodName(HttpRequestMessage request)`, then you get full control over the response you want to send from your method — Subbu, Jun 26 '17 at 11:26
He means, if you are in a controller action, you should be returning a `HttpResponseMessage` or an `IHttpActionResult`. Not be writing to `HttpContext.Current.Response` directly. — peco, Jun 26 '17 at 12:49
Yes, it's a controller method. Still, the fact that I need to return a `HttpResponseMessage` is not helping me. — Tomo, Jun 26 '17 at 12:55

peco · Accepted Answer · 2017-06-27T10:53:42.910

2

With HttpResponseMessage:

public HttpResponseMessage ExampleOne()
{
    var stream = CreatePdf();

    return new HttpResponseMessage
    {
        Content = new StreamContent(stream)
        {
            Headers =
            {
                ContentType = new MediaTypeHeaderValue("application/pdf"),
                ContentDisposition = new ContentDispositionHeaderValue("attachment")
                {
                    FileName = "myfile.pdf"
                }
            }
        },
        StatusCode = HttpStatusCode.OK
    };
}

With IHttpActionResult:

public IHttpActionResult ExampleTwo()
{
    var stream = CreatePdf();

    return ResponseMessage(new HttpResponseMessage
    {
        Content = new StreamContent(stream)
        {
            Headers =
            {
                ContentType = new MediaTypeHeaderValue("application/pdf"),
                ContentDisposition = new ContentDispositionHeaderValue("attachment")
                {
                    FileName = "myfile.pdf"
                }
            }
        },
        StatusCode = HttpStatusCode.OK
    });
}

Here is the CreatePdf method:

private Stream CreatePdf()
{
    using (var document = new Document(PageSize.A4, 50, 50, 25, 25))
    {
        var output = new MemoryStream();

        var writer = PdfWriter.GetInstance(document, output);
        writer.CloseStream = false;

        document.Open();
        document.Add(new Paragraph("Hello World"));
        document.Close();

        output.Seek(0, SeekOrigin.Begin);

        return output;
    }
}

edited Jun 27 '17 at 10:53

answered Jun 26 '17 at 13:02

peco

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How to put the created pdf in the variable `stream`? – Tomo Jun 26 '17 at 14:08
Updated the answer, hope it helps! – peco Jun 26 '17 at 15:00
I pasted your code in my project, but it won't work. I get these errors: `ReadTimeout = 'output.ReadTimeout' threw an exception of type 'System.InvalidOperationException'` and `WriteTimeout = 'output.WriteTimeout' threw an exception of type 'System.InvalidOperationException'` – Tomo Jun 28 '17 at 16:27
When are you getting that exception? `MemoryStream` does not support accessing those properties https://msdn.microsoft.com/en-us/library/system.io.stream.cantimeout(v=vs.110).aspx – peco Jun 28 '17 at 20:12
In the memory stream output. It gets `ReadTimeout` and `WriteTimeout` at t he time of creation. – Tomo Jun 29 '17 at 09:09
Hm, the code works fine for me. Are you sure you are not accessing those properties? https://stackoverflow.com/questions/37006582/stream-read-write-timeout-causes-invalid-operation-exception – peco Jun 29 '17 at 10:26
I don't think it's a timeout problem. CanTimeout is set to false. – Tomo Jun 29 '17 at 11:53
It was a client side - AngularJs issue, nothing to do with your code, which is working like a charm. Anyway, I resolved it. Thank you. – Tomo Jul 03 '17 at 12:06

How to generate PDF with iTextSharp and show/download it from web browser within a WebApi2 C#/.NET project?

1 Answers1