Audio plugin parameters at Matlab are always sliders?

问题

When creating an audio plugin with Matlab's audio toolbox (either when I use the examples given by mathworks), the plugin parameters I add to the interface, always appear as sliders when loading the .dll in my DAWs (tried at Reaper and Cubase). It happens with all the kinds of mappings.

This is how I create the parameters:

properties (Constant)
    PluginInterface = audioPluginInterface(...
        'PluginName','Headphones Converter',...
        'InputChannels',1,...
        'OutputChannels',1,...
        audioPluginParameter('cascos', ...
        'DisplayName','Modelo de cascos', ...
        'Mapping',{'enum','K44','Sennheiser','Otro'}));
end

This is how appears when testing it with audioTestBench(Convolver):

After validateAudioPlugin Convolver and generateAudioPlugin Convolver this is how appears when I load the Convolver.dll file into the reaper. Instead a dropdown, a slider is drawn:

Why is not appearing a dropdown?

来源：https://stackoverflow.com/questions/60631314/audio-plugin-parameters-at-matlab-are-always-sliders