Question

Can you please help me understand what is the issue with generic collection? Thanks in advance!

Error: The model item passed into the dictionary is of type ‘System.Collections.Generic.List1[DomainModel.Product]', but this dictionary requires a model item of type 'System.Collections.Generic.IEnumerable1[DomainModel.Entities.Product]’.

MODEL:

namespace DomainModel.Concrete
{
    public class SqlProductsRepository : IProductsRepository
    {
        private Table<Product> productsTable;

        public SqlProductsRepository(string connString)
        {
            productsTable = (new ProaductDataContext(connString)).GetTable<Product>();
        }

        public IQueryable<Product> Products
        {
            get { return productsTable; }
        }
    }
}

INTERFACE

namespace DomainModel.Abstract
{
    public interface IProductsRepository
    {
        IQueryable<Product> Products { get; }
    }
}

VIEW

<%@ Page Title="" Language="C#"  MasterPageFile="~/Views/Shared/ViewMaster.Master" 
        Inherits="System.Web.Mvc.ViewPage<IEnumerable<DomainModel.Entities.Product>>" %>
<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
Products
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">

    <% foreach (var product in Model)
       { %>
       <div class = "item">
       <h3> <%=product.Name%></h3>
       <%= product.Description%>
       <h4><%= product.Price.ToString("c")%></h4>
       </div>
       <%} %>
</asp:Content>

Answer 1

The error message tells you all your need to know;

The model item passed into the dictionary is of type 
'System.Collections.Generic.List1[DomainModel.Product]', 
but this dictionary requires a model item of type 
'System.Collections.Generic.IEnumerable1[DomainModel.Entities.Product]'.

If you look at your view you can see

<%@ Page Title="" Language="C#"  MasterPageFile="~/Views/Shared/ViewMaster.Master" 
        Inherits="System.Web.Mvc.ViewPage<IEnumerable<DomainModel.Entities.Product>>" %>

The Inherits="System.Web.Mvc.ViewPage<IEnumerable<DomainModel.Entities.Product>>" is what’s tripping you up. You’re passing in an IEnumerable of DomainModel.Product, but you’re expecting something else. It’s a bit strange you have two classes named the same within close to the same namespace, but never mind, you need to ensure you’re using the same class, in the same namespace in both the controller and the view.

So I’d try changing your view to become

<%@ Page Title="" Language="C#"  MasterPageFile="~/Views/Shared/ViewMaster.Master" 
        Inherits="System.Web.Mvc.ViewPage<IEnumerable<DomainModel.Product>>" %>

Then try to figure out why you have two Product classes 🙂