Services as controller properties in a Resource Oriented Architecture

ChatRoomsController.cs

public class ChatRoomsController : ResourceController<ChatRoom>
{
    public ChatRoomsController() : base()
    {
        this.Service = new ChatRoomService(this.ConnectionString); // ConnectionString is inherited from a super class
    }
    
    public ActionResult Index()
    {
        var chatRooms = this.Service.FindAll(cr => cr.Active).Select(cr => new ChatRoomViewModel(cr));
        return this.View(chatRooms);
    }
}

ChatRoomService.cs

public class ChatRoomService : Service<ChatRoom>
{
    public ChatRoomService(string connectionString) : base(connectionString) { }
    
    public override DbSet<ChatRoom> Relation(ChatDbContext context)
    {
        return context.ChatRooms;
    }
}

ResourceController.cs

public abstract class ResourceController<T> : BaseController
{
    public Service<T> Service { get; private set; }
}

Service.cs

public abstract class Service<T>
{
    public string ConnectionString { get; private set; }
    public abstract DbSet<T> Relation(ChatDbContext context);
        
    public Service(string connectionString)
    {
        this.ConnectionString = connectionString;
    }
    
    public List<T> FindAll(Func<T,bool> predicate)
    {
        List<T> results;
        using (var context = new ChatDbContext(this.ConnectionString))
        {
            results = this.Relation(context).All(predicate).ToList();
        }
        
        return results;
    }
}