How to let a ASP.NET page know when a file is ready for download from the server

Question

I\'m maintaining a legacy VB.Net Webforms App and I\'ve got a strange issue after adding one section.

This is this code in the aspx page which shows the giphy.gif w

Answer 1

You are downloading a file (contacts.csv) the UI is never updated because the server can only send one type of response at a time (a file or a html page), so the image will remain visible after download.

To fix this either open the download in a new browser window.

Download CSV

Download CSV

If the download must come after a PostBack then the above solution will not work. A possible solution would be to just hide the image after the average download time of the file.

function ShowProgress() {

    //rest of code

    setTimeout(function () {
        loading.hide();
    }, 2000);
}