List of Items always null MVC 5 - asp.net

Question

I am stuck in this problem and i cannot solve it.
This is my ViewModel
public class AddOrderReceive
{
public string item_name { get; set; }
public DateTime? date_received { get; set; }
public decimal? quantity_received { get; set; }
public bool IsSelected { get; set; }
public decimal? item_rate { get; set; }
}
This is my View
#model List<newtest.Models.AddOrderReceive>
#if(Model != null && Model.Count > 0)
{
for(var i = 0; i < Model.Count; i++)
{
<tr>
#if(Model[i].quantity_remaining == 0)
{
<td colspan="6" class="text-center">Already Sent</td>
}
else
{
#Html.HiddenFor(r => Model[i].item_id)
<td>#Html.CheckBoxFor(r => Model[i].IsSelected)</td>
<td>#Html.EditorFor(r => Model[i].item_rate)</td>
}
</tr>
}
}
And finally, This is my Controller:
[HttpGet]
public ActionResult AddRAR(int? my_id)
{
try
{
var get_items = (from or in db.orders
where or.id == my_id
select new AddOrderReceive()
{
item_name = or.item_name,
quantity_received = or.quantity_receive,
date_received = or.date_receive,
order_receive_id = or.order_receive_id
}).ToList();
foreach(var t in get_items)
{
var get_remain = (from ra in db.order_detail
where ra.contract_id == t.ca_id && ra.order_receive_id == t.order_receive_id
select new
{
consump_quantity = ra.consump_quantity
});
t.quantity_remaining = t.quantity_received - get_remain.Sum(r => r.consump_quantity) ?? t.quantity_received;
}
return View(get_items);
}
catch(Exception ex)
{
}
}
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult AddReceivng(List<AddOrderReceive> rc_form)
{
//Some Logic
}
The problem is that whenever I post the form, it is always null. But when I remove this block:
#if(Model[i].quantity_remaining == 0)
{
<td colspan="6" class="text-center">Already Sent</td>
}
It starts working. I don't know what's the problem. I've searched everywhere but still can't figure out the problem here.

Answer 1

Your #if(Model[i].quantity_remaining == 0) block of code, if its executed in the first iteration, means that your collection indexers would not be zero based. The DefaultModelBinder requires that collection indexers start at zero and be consecutive.
You can override this behavior by including a hidden input for the indexer. Note also that an <input> is not a valid child of a <tr>, and should be inside a <td> element.
for(var i = 0; i < Model.Count; i++)
{
#if(Model[i].quantity_remaining == 0)
{
<td colspan="6" class="text-center">Already Sent</td>
}
else
{
<td>
<input type="hidden" name="Index" value="#i" /> // Add this
#Html.HiddenFor(r => r[i].item_id)
#Html.CheckBoxFor(r => r[i].IsSelected)
</td>
<td>#Html.EditorFor(r => r[i].item_rate)</td>
}
}