Why isn't viewbag value passing back to the view?

Question

straight forward question , can\'t seem to get my viewBag value to display in a view that the user is directed to after completing a form.

Please advise..thanks

Answer 1

ViewBag only lives for the current request. In your case you are redirecting, so everything you might have stored in the ViewBag will die along wit the current request. Use ViewBag, only if you render a view, not if you intend to redirect.

Use TempData instead:

TempData["Message"] = "Profile Updated Successfully";
return RedirectToAction("Index");

and then in your view:

@if (TempData["Message"] != null)
{
    <div>
        <button type="button">@TempData["Message"]</button>
    </div>
}

Behind the scenes, TempData will use Session but it will automatically evict the record once you read from it. So it's basically used for short-living, one-redirect persistence storage.

Alternatively you could pass it as query string parameter if you don't want to rely on sessions (which is probably what I would do).

Answer 2

You can try this way also

Controller

public ActionResult Test()
    {
ViewBag.controllerValue= "testvalue";
 ..................
    }

View - define top of razor page @{string testvalue= (string)ViewBag.controllerValue;}

$(function () {
       var val= '@testvalue';
});

Answer 3

RedirectToAction causes an HTTP 302 response, which makes the client make another call to the server and request a new page.

You should be returning a view instead of redirecting.

Answer 4

The RedirectToAction(msdn) instructs your browser to make a new request.
So your server will be called again but it will be a new request with a blank viewbag and all
You could do a sort of internal redirect by just calling the index method, this way the viewbag will still have its data.

Edit : you'll also have to modify your index method or your View(model) line will try to render the edit.
Full code below

public ActionResult Index()
{
    var source = _repository.GetByUserID(_applicationUser.ID);
    var model = new RefModel
    {
        test1 = source.test1,
    };
    return View("Index",model);
}


[HttpPost]
public ActionResult Edit(RefModell model)
{
    if (ModelState.IsValid)
    {
        var source = _repository.GetByUserID(_applicationUser.ID);
        if (source == null) return View(model);

        source.test1 = model.test1;
        _uow.SaveChanges();

        @ViewBag.Message = "Profile Updated Successfully";
        return Index();      
    }
    return View(model);
}