未调用 onDateSet()

问题描述

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。互联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过于繁琐（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,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！

解决方法

@laalto 提出我在调用 getTargetFragment() 之前没有编写 setTargetFragment() 方法的可能性。就是这种情况，在添加 setTargetFragment() 之后调用了 onDateSet()。