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The property 'UserId' cannot be configured as a navigation property. The property must be a valid entity type and the property should have a non-abstract getter and setter. For collection properties the type must implement ICollection<T> where T is a valid entity type.

کد مربود به content

using System;
using System.ComponentModel.DataAnnotations;
using Languages.Resources;
using System.ComponentModel.DataAnnotations.Schema;
using System.Collections.Generic;
using Domain.ViewModels;
using System.Web.Mvc;

namespace Domain.Domain
{
    public abstract class Content
    {
        public Content()
        {
            this.LastModifyDate = DateTime.Now;
        }

        #region public
        [Required]
        [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int Id { get; set; }
        [StringLength(1000, ErrorMessageResourceName = "Between", ErrorMessageResourceType = typeof(Error), MinimumLength = 1)]
        [Required(ErrorMessageResourceName = "IsRequired", ErrorMessageResourceType = typeof(Error))]
        [Display(Name = "Title", ResourceType = typeof(DomainLabel))]
        [MaxLength(1000)]
        public string Title { get; set; }
       .
       .
       .
        [ForeignKey("User")]
        public int UserId { get; set; }
        public virtual User User { get; set; }

        #endregion



    }
}

کد مربوط به جدول User

using Languages.Resources;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

namespace Domain.Domain
{
    public class User
    {
        [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int Id { get; set; }
        [Required(ErrorMessageResourceName = "IsRequired", ErrorMessageResourceType = typeof(Error))]
        [Display(Name = "Alias", ResourceType = typeof(DomainLabel))]
        [MaxLength(100)]
        public string Alias { get; set; }
        [Display(Name = "Avatar", ResourceType = typeof(DomainLabel))]
        public string Avatar { get; set; }
        [Required(ErrorMessageResourceName = "IsRequired", ErrorMessageResourceType = typeof(Error))]
        [Display(Name = "Email", ResourceType = typeof(DomainLabel))]
        [MaxLength(200)]
        [DataType(DataType.EmailAddress, ErrorMessageResourceName = "IsNotValid", ErrorMessageResourceType = typeof(Error))]
        public string Email { get; set; }
        public string HashPassword { get; set; }
        [ForeignKey("Role")]
        public int RoleId { get; set; }
        public virtual Role Role { get; set; }

    }
}