java - 单个微调器上的多个 onItemSelected 监听器

Question

我有一个微调器，它附加了一个基本的 onItemSelected 监听器。现在我想要的是将多个其他 onItemSelected 监听器添加到此微调器中，并且我希望它们全部执行。如何实现？

Answer 1

将其设置为 Spinner 的监听器，然后将其他监听器添加到此:

class ItemSelectedMultiListener implements OnItemSelectedListener {

    private List<OnItemSelectedListener> mListeners = new ArrayList<>();

    public void addListener(OnItemSelectedListener listener) {
        mListeners.add(listener);
    }

    public void removeListener(OnItemSelectedListener listener) {
        mListeners.remove(listener);
    }

    @Override
    public void onItemSelected(...args...) {
        for (OnItemSelectedListener listener : mListeners) {
            listener.onItemSelected(...args...);
        }
    }

    @Override
    public void onNothingSelected(...args...) {
        for (OnItemSelectedListener listener : mListeners) {
            listener.onNothingSelected(...args...);
        }
    }
}