android - 获取当前 fragment 变量值

Question

我正在使用 FragmentViewPagerAdapter 创建日历 Activity 。每个 fragment 代表一天，我的主要 Activity 上有一个开关，允许用户过滤每个 fragment 的结果。 我正在使用 ViewModel 请求数据，所以当切换被选中时，我需要向我的服务器发出新请求以获取每个 fragment 的新数据，我的问题是当我发出请求时，发送的日期是下一个 fragment 的日期，不是现在的。

我已经尝试将屏幕页面限制为 0，但没有任何改变。

public class PoiPlanningFragment extends Fragment implements InitApplicationListener{

MutableLiveData<Boolean> filtered = new MutableLiveData<>();
private Context mContext;
DateTime startTime;
DateTime  endTime;
switcher = getActivity().findViewById(R.id.app_switcher);

public PoiPlanningFragment() {
    // Required empty public constructor
}


public static Fragment getInstance(int position, String date, String resourceId, String resourceType,boolean filter) {
    Bundle bundle = new Bundle();
    bundle.putInt("pos", position );
    bundle.putString("date", date);
    bundle.putString(ARG_RESOURCE_ID, resourceId);
    bundle.putString(ARG_RESOURCE_TYPE, resourceType);
    PoiPlanningFragment tabFragment = new PoiPlanningFragment();
    tabFragment.setArguments(bundle);
    return tabFragment;
}

  @Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    DateTimeFormatter horaire = DateTimeFormat.forPattern("yyyy-MM-dd HH:mm");
    startTime = horaire.parseDateTime(date.concat(" " + STARTHOUR));
    endTime = horaire.parseDateTime(date.concat(" " + ENDHOUR));
    // Inflate the layout for this fragment
    return inflater.inflate(R.layout.fragment_poi_planning, container, false);
}

 @Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {

//Switch my meetings
    switcher.setOnCheckedChangeListener(new SwitchClickedListener(this.filtered));

     //Observes whether the user has a filter on own meetings or not
    filtered.observe(this, filtered -> {
        //here startTime always shows next tab startTime and endTime
        BookingRepository.getUserPlanning(planning,resourceId,Utility.toTimeStamp(startTime),Utility.toTimeStamp(endTime), filtered);
        loader.setVisibility(View.VISIBLE);
    });

}

}

private class SwitchClickedListener implements CompoundButton.OnCheckedChangeListener{
    MutableLiveData<Boolean> listener;

    SwitchClickedListener(MutableLiveData<Boolean> listener){
        this.listener = listener;
    }
    @Override
    public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
        //Set filter to true
        this.listener.setValue(b);
    }
}


public class PoiPlanningViewPagerAdapter extends FragmentStatePagerAdapter {

private final static String TAG = PoiPlanningViewPagerAdapter.class.getName();
private List<Date> dateList;
private Context context;
private String poiId;
private String resouceType;

public PoiPlanningViewPagerAdapter(FragmentManager fm, List<Date> dates, String poidId,String resourceType, Context context) {
    super(fm);
    this.dateList = dates;
    this.context = context;
    this.poiId = poidId;
    this.resouceType = resourceType;
}

@Override
public Fragment getItem(int position) {
    Date datetime = dateList.get(position);
    DateFormat df = new SimpleDateFormat("yyyy-MM-dd");
    String date = df.format(datetime);
    PoiPlanningFragment planningFragment = (PoiPlanningFragment) PoiPlanningFragment.getInstance(position, date, poiId,resouceType,false);
    return planningFragment;
}

@Override
public int getCount() {
    return dateList.size();
}

@Override
public CharSequence getPageTitle(int position) {
    Date datetime = dateList.get(position);
    DateFormat df = new SimpleDateFormat(context.getString(R.string.date_format));
    String date = df.format(datetime);
    return date;
}


}

在前面的代码中，如果我检查开关并且我在星期一 02 11 它将加载星期二的数据。

Answer 1

您可以使用 supportFragmentManager 获取当前 fragment 。

下面的代码会帮助你。

if (getSupportFragmentManager().getBackStackEntryCount() > 1) {
        val frag = getSupportFragmentManager().findFragmentById(R.id.container);
        if (frag is HomeFragment) {
           Fragment currentFragment = (HomeFragment) frag;
            //do your code
            return
        }
    } 

希望对您有所帮助。