未调用 onDateSet()

Question

查看了类似问题的答案，但不知道如何将它们应用到我的代码中。网上有关于此功能的信息，但可能是因为 Android 代码与其他代码相比非常繁琐（以我的经验），我很难找到问题所在。

日历片段：

public class CalendarFragment extends DialogFragment{

@RequiresApi(api = Build.VERSION_CODES.N)
@NonNull
@Override
public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {

    Calendar calendar = Calendar.getInstance();
    int year = calendar.get(Calendar.YEAR);
    int month = calendar.get(Calendar.MONTH);
    int day = calendar.get(Calendar.DAY_OF_MONTH);
    return new DatePickerDialog(getActivity(), (DatePickerDialog.OnDateSetListener)getTargetFragment(),
            year, month, day);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    return inflater.inflate(R.layout.fragment_calendar, container, false);
}

public void onViewCreated(@NonNull View view, Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
}
}

日期片段：

public class DatesFragment extends Fragment implements DatePickerDialog.OnDateSetListener {

String selectedDate;

@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable 

ViewGroup container, @Nullable Bundle savedInstanceState) {

    View view = inflater.inflate(R.layout.fragment_dates, container, false);
    showCalendar = view.findViewById(R.id.calendar_button);
    showCalendar.setOnClickListener(v -> {
    DialogFragment calendarFragment = new CalendarFragment();
    calendarFragment.show(getChildFragmentManager(), "calendar");
//        ...

    return view;
}

@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
}

@Override
public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) {
    Calendar calendar = Calendar.getInstance();
    calendar.set(Calendar.YEAR, year);
    calendar.set(Calendar.MONTH, month);
    calendar.set(Calendar.DAY_OF_MONTH, dayOfMonth);
    selectedDate = DateFormat.getDateInstance(DateFormat.FULL).format(calendar.getTime());
}

谢谢！

Answer 1

@laalto 提出了我在调用 getTargetFragment() 之前没有编写 setTargetFragment() 方法的可能性。就是这样，添加 setTargetFragment() 后调用 onDateSet()。