Metadata were not loaded using MetadataType

Question

I've got a some problem/question about MetadataType. I've got DLL helper-project for data access from MS SQL Server using LinqToSQL. I've also need to add a metadata for a generated class ClientInfoView. I've done it following way:

using System;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel;

namespace DataAPI.LINQToSQL
{
    [MetadataType(typeof(ClientInfoViewMetaData))]
    public partial class ClientInfoView
    {
        internal sealed class ClientInfoViewMetaData
        {
            [Category("Main Data"), DisplayName("Client ID")]
            public int ID { get; set; }

            [Category("Main Data"), DisplayName("Login")]
            public string Login { get; set; }

            ...
        }
    }
}

But when I checked the attributes in runtime, I've found that ClientInfoView hasn't got any attributes.

Can you please help me to find a mistake?

Answer 1

To give some part of the answer , you can check ClientInfoView has got attributes. Some small demo that worked for me. Still trying to find why I can't access those attributes in ClientInfoViewMetaData individual properties

    static void Main(string[] args)
    {
        TypeDescriptor.AddProviderTransparent(
        new AssociatedMetadataTypeTypeDescriptionProvider(typeof(ClientInfoView), typeof(ClientInfoViewMetaData)), typeof(ClientInfoView));
        ClientInfoView cv1 = new ClientInfoView() { ID = 1 };
        var df = cv1.GetType().GetCustomAttributes(true);
        var dfd = cv1.ID.GetType().GetCustomAttributes(typeof(DisplayNameAttribute), true);
        var context = new ValidationContext(cv1, null, null);
        var results = new List<ValidationResult>();
        var isValid = Validator.TryValidateObject( cv1,context, results, true);
    }
}

    [MetadataType(typeof(ClientInfoViewMetaData))]
    public partial class ClientInfoView
    {
        public int ID { get; set; }
        public string Login { get; set; }
    }

public class ClientInfoViewMetaData
{        
    [Required]
    [Category("Main Data"), DisplayName("Client ID")]
    public int ID { get; set; }

    [Required]
    [Category("Main Data"), DisplayName("Login")]
    public string Login { get; set; }

}