Writing a file as well as JavaScript (to be executed) to an ASP.NET Response

Question

I have code which successfully writes a PDF file to the response:

JS:

function DownloadPDF() {
    ShowLoader();
    window.location.href = _appPath + 'export/' + id;
}

C#:

System.Web.HttpResponse response = System.Web.HttpContext.Current.Response;
response.Clear();
response.AddHeader("Content-Type", "application/pdf");
response.AddHeader("Content-Disposition", String.Format("attachment; filename=" + filename + ".pdf; size={0}", buffer.Length.ToString()));
response.BinaryWrite(buffer);
response.End();

I am trying to also send a single line of JavaScript back to the client (which is not working):

// the following appears just before the response.End()
response.Write("<script type='text/javascript'>");
response.Write("HideLoader();");
response.Write("</script>");

Probably self-explanatory, but when the user clicks to download the file, I want there to be an AJAX-like loader gif, which then is hidden once the response is complete. How do I achieve something like this?

edit: I tried Page.ClientScript.RegisterStartupScript(GetType(), "hideloader", "HideLoader();", true); before and after the block of code that writes the file. It doesn't work either.

try with the function in this answer http://stackoverflow.com/a/29924444/4773983, then call it like this callJavascriptFunction("HideLoader();"); — Enrique Zavaleta, Jul 15 '15 at 13:26
@EnriqueZavaleta, I should've mentioned - I already tried that method and it doesn't work — notAnonymousAnymore, Jul 15 '15 at 13:27
It doesn't hide the loader gif :) (I've executed JS with `RegisterStartupScript` before and it works, but never alongside writing a file like this) — notAnonymousAnymore, Jul 15 '15 at 13:31
You could use an ajax request, example in this question (http://stackoverflow.com/questions/20830309/download-file-using-an-ajax-request), and call the `HideLoader()` function in the success callback. — Bryan Weaver, Jul 15 '15 at 13:31
If you are navigating to a new page, why not just use $.ready() JQuery and hide the loader? Or use a javascript callback with ajax? — Daniel Hoffmann-Mitscherling, Jul 15 '15 at 13:33
Have you tried delete the response.End(); line and use the RegisterStartupScript you say that works? — Enrique Zavaleta, Jul 15 '15 at 13:36

Writing a file as well as JavaScript (to be executed) to an ASP.NET Response

0 Answers0