Bind viewmodel to partial view - asp.net-mvc

Question

I have a model, which can represent 3 categories. I want in my view, make 3 different tables for each category with relevant fields. I think for this I need to use partial view with viewmodel for each category.
So my main model is "Ad", which have 3 sub viewmodels (Realty, Auto and Service).
Here the example how I implement Realty action on my home controller:
public ActionResult Realty()
{
var ads = db.Ads.Include(a => a.Realty);
var vm = new List<RealtyViewModel>();
foreach (var ad in ads)
{
vm.Add(new RealtyViewModel
{
Title = ad.Title,
Descirpiton = ad.Descirpiton,
Type = ad.Realty.Type,
NumberOfRooms = ad.Realty.NumberOfRooms
});
}
return PartialView(vm);
}
Then my partial view, looks like this:
#model IEnumerable<OGAS.Areas.Category.ViewModels.RealtyViewModel>
<table class="table">
<tr>
<th>
#Html.DisplayNameFor(model => model.Title)
</th>
<th>
#Html.DisplayNameFor(model => model.Type)
</th>
<th>
#Html.DisplayNameFor(model => model.Descirpiton)
</th>
<th>
#Html.DisplayNameFor(model => model.NumberOfRooms)
</th>
<th></th>
</tr>
#foreach (var item in Model)
{
<tr>
<td>
#Html.DisplayFor(modelItem => item.Title)
</td>
<td>
#Html.DisplayFor(modelItem => item.Type)
</td>
<td>
#Html.DisplayFor(modelItem => item.Descirpiton)
</td>
<td>
#Html.DisplayFor(modelItem => item.NumberOfRooms)
</td>
</tr>
}
</table>
Then in my Index page (without using any models), I call partial view like this:
#{Html.RenderPartial("Realty");}
But then I'm getting following error:
An exception of type 'System.NullReferenceException' occurred in App_Web_gdyh352c.dll but was not handled in user code
Could you please advise if this approach is good (calling 3 vms), if yes how to implement this?
Thanks.

Answer 1

Try to replace #{Html.RenderPartial("Realty");} and use #Html.Action("Realty") in this case, as you need to call back to the controller action, in order to create the model for the partial view.
See MVC Html.Partial or Html.Action for more information.

Answer 2

Use this, for .net core and mvc. #Html.Action has been removed from .net core
#await Html.PartialAsync("_YourPartialViewName", YourModel)