public void RemoveSoundListener(IChangeSoundListener listener) { if((_soundListeners != null)&&(_soundListeners.Contains(listener))) { _soundListeners.Remove(listener); } }
public void AddNewSoundListener(IChangeSoundListener listener) { if(_soundListeners == null) _soundListeners = new List<IChangeSoundListener>(); if(!_soundListeners.Contains(listener)) { _soundListeners.Add(listener); } }