PartialView redirects rather than inserts - asp.net-mvc

Question

I have a form and a partial view on my razor page, the idea being that if I change the dropdownlist, the Controller does some work and sets a ViewBag.ShowAlert (bool) that triggers the partial view to be displayed.
While this works, instead of just showing the code within the partial view, the partial view shows as a new view rather than on the same view.
Any idea why?
The view looks like this
#using (Html.BeginForm("AlterVote", "ChangeVoteType"))
{
#Html.AntiForgeryToken()
<div class="form-horizontal">
<h1>New voting preference</h1>
<hr />
<p>Please select the type of vote you wish to change to #Html.DropDownListFor(model=>model.SelectedType, ViewBag.myList as SelectList, "Voting type", new { onchange = "this.form.submit();"})</p>
<div id="partialDiv">
#if (ViewBag.ShowAlert)
{
#Html.Partial("VotingChange")
}
</div>
</div>
}
The controller handling the HttpPost is this
[HttpPost]
public PartialViewResult AlterVote(Dropdown dropType)
{
ChangeBoilerPlate(dropType.SelectedType);
dropType.CurrentType = VoteTypeNames[(int)HomeController.VoterModel.CurrentVoteType];
return PartialView("VotingChange", dropType);
}
I'm guessing that this is down to the initial view being a form, so the partial gets confused as to where to insert the view.

Answer 1

If I understand correctly, by the partial view shows as a new view you mean it comes with a html tag, body and the full layout again. To solve this, you need to set up the layout to null inside your partial view, like so:
#model YourNamespace.Dropdown
#{
Layout = null;
}
<!-- partial view html below -->
<div>
</div>
The div tag is just to illustrate.
While this might solve your problem, you might want to load the partial view without reloading the whole page again. This is possible using ajax, like so:
Main View
#using (Html.BeginForm("AlterVote", "ChangeVoteType"))
{
#Html.AntiForgeryToken()
<div class="form-horizontal">
<h1>New voting preference</h1>
<hr />
<p>Please select the type of vote you wish to change to #Html.DropDownListFor(model=>model.SelectedType, ViewBag.myList as SelectList, "Voting type", new { id = "vote"})</p>
<div id="partialDiv">
</div>
</div>
}
<script type="text/javascript">
$(document).ready(function () {
$('#vote').change(function() {
var selectedType = $(this).val();
$.post('yourserver/YourController/AlterVote', { "SelectedType": selectedType })
.done(function (data) {
$('#partialDiv').html(data);
})
.fail(function () {
console.log('Whoops, something went wrong!!!');
});
});
});
</script>
So I just added a javascript to listen to that same change event on your dropdrown, but instead of submitting the form, I just use ajax to load the partial view html without reloading the entire page.
Just fix the URL and remember to set up layout to null in your partial view. Also, you might want this javascript in a separate file, thus loading it with bundles.