Redirect / show view after generated file is dowloaded

Question

I\'ve got a controller action that downloads a dynamically generated file:

    public ActionResult DownloadFile()
    {
        var obj = new MyClass { MyStr         


        

Answer 1

Here is how I redirected after the file is downloaded. The main logic is to wait the redirect until the file is downloaded. To do that, a server side response is calculated and redirect is delayed using server side response time + some offset.

Server Side Controller Code:

[HttpPost]
public ActionResult GetTemplate()
    {
        return Json(new {Url = Url.Action("ReturnTemplate") });
    }

[HttpGet]
public ActionResult ReturnTemplate()
    {
        FileResult fileResult = // your file path ;
        return fileResult;
    }

Client Side Code:

<div id="btnGen" align="right"><button class="main-button"     id="generateTemplate" type="Submit"></div>

Javascript:

$("#generateTemplate").click(function () {
    var startTime = (new Date()).getTime(), endTime;

        $.ajax({
            url: '@Url.Action("GetTemplate", "Controller")',
            type: 'POST',
            traditional: true,
            dataType: "json",
            contentType: "application/json",
            cache: false,
            data: JSON.stringify(),
            success: function (result) {
                endTime = (new Date()).getTime();
                var serverResponseTime = endTime - startTime + 500;
                setInterval(function () { Back() }, serverResponseTime);
                window.location = result.Url;
            }
        });
});

function Back() {
    window.location = '@Url.Action("Index","Controller")';
}

Answer 2

Each HTTP request can only have one response - you're trying to sneak in two (the file, and a page).

Normally when you send a "Content-Disposition: attachment" HTTP header the browser will stay on the current page and pop a file save dialog (or automatically save the file in your downloads).

You're going to have to change your strategy if you want to prevent re-submission of the form. I'd suggest a bit of javascript to disable the form's submit button and show the "Completed" message in a div overlay?

Answer 3

As Ross has said, you can only return one response to a HTTP request. What i do in that case is:

1. Send the request to the server
2. The server generates the file and stores it in some server side data structure (Cache, Usersession, TempData)
3. The server returns a RedirectToAction() (POST, REDIRECT, GET pattern)
4. The redirected action returns a View with some javascript which
5. Triggers the download of the pregenerated file by setting window.location.href property to an special download action which sends the file back to the browser