在客户端上下载Web API发送的pdf字节数组

Question

I am exporting crystal report to a pdf document and there is a button in UI that downloads that pdf in "Downloads" folder. To achieve this I have a method in web api that gets executed on button click and that method returns HttpResponseMessage whose contents are the byte array (the pdf resides on blob and I download that file to a byte array). From UI, using window.open method of javascript I am directly opening the URL of the web api method which when executed downloads the file in downloads folder.

This works fine. But now I have added [Authorize] attribute to the web api controller and hence when javascript window opens with the method URL, user is prompted for a user name and password value.

I am trying to post an ajax request to the server which returns me byte array on client. After the ajax request is executed, I have written the code below:

data = "data:application/octet-stream;base64," + data;
document.location = data;

The file does get downloaded but it gets downloaded as a "download" file for which I have to use "Open with.." option to view the file. How can I download it as a pdf document ?

Answer 1

If you are trying to serve a file with WebApi, you can do this:

 HttpResponseMessage response = Request.CreateResponse(HttpStatusCode.OK);
 Stream fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read, 4096, true);
 response.Content = new StreamContent(fileStream);
 response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
 response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment");
 response.Content.Headers.ContentDisposition.FileName = "myfilename.pdf";

  return response;

You don't need to manually dispose the stream, the framework calls HttpResponseMessage.Dispose, which calls StreamContent.Dispose, which calls FileStream.Dispose.