Asp.net '；数据表'；没有定义键

尝试添加新迁移时出错

我在谷歌上搜索了一下，似乎解决办法是在ID中添加一个[Key]，但这在我的情况下不起作用。我怀疑这个错误是概念性的。这是我的模型：

namespace steer.Models
{
    public class UpFile
    {
        [Display(Name="Auðkenni")]
        public int ID { get; set; }
        [Required]
        [Display(Name="Nafn")]
        public string Name { get; set; }

        [Display(Name = "Hlaðið þann")]
        public DateTime Date { get; set; }

        [Display(Name="Tegund")]
        public string FileType { get; set; }

        [Display(Name = "Stærð (kB)")]
        public int Size { get; set; }

        public DataTable Excel { get; set; }

        public class UpFileDBContext : DbContext
        {
            public DbSet<UpFile> UpFiles { get; set; }
        }

    }
}

One or more validation errors were detected during model generation:

steer.Models.DataTable: : EntityType 'DataTable' has no key defined. Define the key for this EntityType.
steer.Models.CultureInfo: : EntityType 'CultureInfo' has no key defined. Define the key for this EntityType.
steer.Models.DateTimeFormatInfo: : EntityType 'DateTimeFormatInfo' has no key defined. Define the key for this EntityType.
DataTables: EntityType: EntitySet 'DataTables' is based on type 'DataTable' that has no keys defined.
CultureInfoes: EntityType: EntitySet 'CultureInfoes' is based on type 'CultureInfo' that has no keys defined.
DateTimeFormatInfoes: EntityType: EntitySet 'DateTimeFormatInfoes' is based on type 'DateTimeFormatInfo' that has no keys defined.