How to prevent controllers from loading in ASP.NET Core 6 MVC

I would like to suppress loading of controllers based on a configuration variables available to Startup. I am using .NET 6.0.

I've tried implementing subclasses of either DefaultControllerFactory (inspired by this: How does DefaultControllerFactory Handle Content Requests) or DefaultHttpControllerTypeResolver (inspired by this: How to restrict Asp.net Web API / Owin discovery of controllers by namespace?), but neither of those classes seem to exist in my project.

Is there an updated class I should be using in .NET 6.0 or a different way to restrict loading of specific controllers in .NET 6.0?

You can implements IApplicationModelConvention:

public class MyControllerConvention : IApplicationModelConvention
{
    private readonly bool _shouldLoadControllers;

    public MyControllerConvention(IConfiguration configuration)
    {
        // Read the config value that decides whether to load controllers or not
        _shouldLoadControllers = configuration.GetValue<bool>("LoadControllers");
    }

    public void Apply(ApplicationModel application)
    {
        if (!_shouldLoadControllers)
        {
            //e.g  TestController, controller name is Test
            var controllersToRemove = application.Controllers
                .Where(c => c.ControllerName == "Test")
                .ToList();
            //if you want to exclude specific type of controller. eg.TestController inherit from ControllerBase
            //var controllersToExclude = application.Controllers
                 //.Where(c => c.ControllerType.BaseType == typeof(ControllerBase))
                 //.ToList();
            foreach (var controller in controllersToRemove)
            {
                application.Controllers.Remove(controller);
            }
        }
    }
}

Register the Custom Convention in Program.cs:

builder.Services.AddControllers(options =>
{
    options.Conventions.Add(new MyControllerConvention(builder.Configuration));
});

You can define a configuration value to control whether the controllers should be loaded or not in appsettings.json:

{    
  "LoadControllers": false    
}