Question

I have the following type hierarchy for ClientIndexModel:

public class ViewModel
{
    public virtual IDictionary<string, SelectList> SelectListDictionary
    {
        get
        {
            var props = GetType().GetProperties().Where(p => p.PropertyType == typeof(SelectList));
            return props.ToDictionary(prop => prop.Name, prop => (SelectList)prop.GetValue(this, null));
        }
    }
}
public class IndexModel<TIndexItem, TEntity> : ViewModel where TIndexItem : ViewModel where TEntity : new()
{
    public List<TIndexItem> Items { get; private set; }
}
public class ClientIndexModel: IndexModel<ClientIndexItem, Client>
{
}

I instantiate in and return a ClientIndexModel from an ApiController as follows:

public ClientIndexModel Get()
{
    var model = new ClientIndexModel();
    return model;
}

If I inspect model with a breakpoint on the return model; line, the Items property is present, with a count of 0. Yet the JSON returned from this action only has the SelectListDictionary property and no Items property. Why could this be?

Answer 1

Your Items property has a private setter. Properties with private setters are intentionally omitted from serialization as it makes no sense to serialize them because they can never be deserialized back as their values cannot be modified from the outside. So you should either completely remove the setter (as you have done for the SelectListDictionary property), make it public or write a custom formatter using some custom serializer that is capable of serializing properties with private setters.