ASP.Net MVC 6 PartialView model binding confusion - asp.net-core-mvc

Question

Background
We need to submit model with items. For that purpose, we make this complex model:
public class PaymentViewModel
{
public decimal? Payment { get; set; }
public string Description { get; set; }
public List<SplittedPaymentViewModel> SplittedPayment { get; set; } = new List<SplittedPaymentViewModel>();
}
public class SplittedPaymentViewModel
{
public short SplittedPaymentId { get; set; }
public decimal? Payment { get; set; }
public string Description { get; set; }
}
For rendering html, we this two views, one regular: CreatePayment
#model ZevApp.ViewModels.Record.PaymentViewModel
...
<input class="form-control" asp-for="Payment" type="number" />
<input class="form-control" asp-for="Description" />
...
<div class="panel-body" id="SplittedPayments">
#foreach (var spItem in Model.SplittedPayment)
{
#Html.Partial("SplittedPaymentPartial", spItem);
}
...
</div>
And the other Partial: SplittedPaymentPartial
#model ZevApp.ViewModels.Record.SplittedPaymentViewModel
...
<input class="form-control" asp-for="Payment" type="number" />
<input class="form-control" asp-for="Description" />
...
As you can see, from the first view, we call partial view and pass them item by item form the SplittedPayment list.
Unexpectedly behavior
We run the code but unexpectedly behavior is occur:
Each partial view bind Payment and Description form parent PaymentViewModel, not from a passed item?
Does anybody know what is wrong?
Each view define model at the beginning of the file.
From the controller we return PaymentViewModel, and for a test, there are tree SplittedPaymentViewModels. But we can't see values from the items.

Answer 1

I found that problem was CreatePayment.cshtml (thanks to the people from MVC community). It doesn't provide any information about the spItem expression when invoking the partial view.
var savePrefix = ViewData.TemplateInfo.HtmlFieldPrefix;
for (var i = 0; i < Model.SplittedPayment.Count; i++)
{
ViewData.TemplateInfo.HtmlFieldPrefix = Html.NameFor(m => m.SplittedPayment[i]);
var spItem = Model.SplittedPayment[i];
#Html.Partial("SplittedPaymentPartial", spItem);
ViewData.TemplateInfo.HtmlFieldPrefix = savePrefix;
}
You can find full description on https://github.com/aspnet/Mvc/issues/4106