I have a Entity Framework generated class for one of my context items. (EF8 /.net8 Blazor Server) This class looks like this:

namespace ChargeModels
{
    public partial class Individual
    {
        public Individual()
        {
            BatchLines = new HashSet<BatchLine>();
        }

        public int id { get; set; }
        public int name { get; set; }
        public int? reference { get; set; }
    }
}

I want to “extend” this class to have some methods I can call directly from an “individual” object. I have created this class to do this:

namespace ChargeModels
{
    public partial class Individual
    {
        private readonly IDbContextFactory<ChargingContext> _factory;

        public Individual(IDbContextFactory<ChargingContext> factory)
        {
            _factory = factory;
        }
        public bool HasBills()
        {
            using (var context = _factory.CreateDbContext())
            {
               return context.ExistingBills.Where(x => x.IndividualId==id).Any(); 
            }
        }
    }
}

In my Program.cs I do this:

 builder.Services.AddDbContextFactory<ChargingContext>(options => options.UseSqlServer(config.GetConnectionString("ChargingConnection")));

With this pattern I was hoping to be able to perform this kind of operation:

    public Individual BuildModel(int id)
    {
        var individual = _service.GetIndividual(id);
        var hasBills = individual.HasBills();
    }

Some of this is working as I might expect. I can get an “Individual” object from the database and it has .HasBills() available as a method I can call. The part I cannot figure out is why my _factory is always null. The overload constructor is never called leading to _factory never getting enumerated from my DI factory being passed in.

I am using the same factory in all my “normal” services just fine so I must be using this partial incorrectly.

Can anyone offer me any advice on what I am doing wrong?