If I have a property like this in my model:
[BindProperty]
public IPagedList<Product> Products { get; set; }
then when I try to post, I get this error:
An unhandled exception occurred while processing the request.
InvalidOperationException: Could not create an instance of type 'X.PagedList.IPagedList`1[Data.Models.Product, Data, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]'. Model bound complex types must not be abstract or value types and must have a parameterless constructor. Alternatively, set the 'Products' property to a non-null value in the 'Areas.Catalog.Pages.ProductListModel' constructor.
The error says I can set the property to a non-null value in the constructor, so I try to do this in the constructor:
Products = new PagedList<Product>(Enumerable.Empty<Product>(), 1, 10);
But I get the same error.
If a new Razor Pages project is created and the following amends made it works fine:
Product.cs:
public class Product
{
public int Id { get; set; }
public string Name { get; set; }
}
Index.cshtml:
@page
@using X.PagedList;
@using X.PagedList.Mvc.Core;
@model IndexModel
@{
ViewData["Title"] = "Home page";
}
<div class="text-center">
<h1 class="display-4">Welcome</h1>
<p>Learn about <a href="https://docs.microsoft.com/aspnet/core">building Web apps with ASP.NET Core</a>.</p>
</div>
@{
foreach (var item in Model.Products)
{
<div> @item.Name</div>
}
}
@Html.PagedListPager((IPagedList)Model.Products, page => Url.Action("Index", new { page }))
Index.cshtml.cs
public class IndexModel : PageModel
{
public IndexModel()
{
Products = new PagedList<Product>(Enumerable.Empty<Product>(), 1, 10);
}
[BindProperty]
public IPagedList<Product> Products { get; set; }
public void OnGet()
{
}
}
As such I suspect the issue to be with complexity in your Product class which you have not provided the code for.
To verify that, use a temporary simple Product class (like that in my example) as a test.
Once confirmed, try projecting the product class to a simpler class using Automapper or linq's Select method and see if that helps:
https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/concepts/linq/basic-linq-query-operations#selecting-projections
http://docs.automapper.org/en/stable/Projection.html
When I remove [BindProperty] it works. I was under the impression I needed that to bind a property on a Razor page, but I guess not?
