Android 里面自定義監(jiān)聽(tīng)器我沒(méi)搞明白. 監(jiān)聽(tīng)器是能夠做到每時(shí)每刻監(jiān)聽(tīng)是嗎? 那像這些自己寫(xiě)出來(lái)的監(jiān)聽(tīng)器究竟是怎么做到監(jiān)聽(tīng)的?像這個(gè)Android 幫助文檔上的實(shí)現(xiàn) dialog 的代碼(代碼如下), 自己編的一個(gè) interface 被 MainActivity 繼承為什么就能做到監(jiān)聽(tīng)? — NoticeDialogListener為什么能夠接收到點(diǎn)擊按鈕的事件呢?以下是上述文檔的代碼. 當(dāng)然我問(wèn)的也不僅僅是這個(gè)代碼了… 謝謝回答!For example, here's a DialogFragment that defines an interface throughwhich it delivers the events back to the host activity:public class NoticeDialogFragment extends DialogFragment {    /* The activity that creates an instance of this dialog fragment must     * implement this interface in order to receive event callbacks.     * Each method passes the DialogFragment in case the host needs to query it. */    public interface NoticeDialogListener {        public void onDialogPositiveClick(DialogFragment dialog);        public void onDialogNegativeClick(DialogFragment dialog);    }    // Use this instance of the interface to deliver action events    NoticeDialogListener mListener;    // Override the Fragment.onAttach() method to instantiate the NoticeDialogListener    @Override    public void onAttach(Activity activity) {        super.onAttach(activity);        // Verify that the host activity implements the callback interface        try {            // Instantiate the NoticeDialogListener so we can send events to the host            mListener = (NoticeDialogListener) activity;        } catch (ClassCastException e) {            // The activity doesn't implement the interface, throw exception            throw new ClassCastException(activity.toString()                    + " must implement NoticeDialogListener");        }    }    ... }The activity hosting the dialog creates an instance of the dialog withthe dialog fragment's constructor and receives the dialog's eventsthrough an implementation of the NoticeDialogListener interface:public class MainActivity extends FragmentActivity                          implements NoticeDialogFragment.NoticeDialogListener{    ...