如何在从下一个片段按下的背面显示片段列表？

Question

我有 MyTrips fragment，其中包含 ViewPager。所以它包含两个选项卡，即两个片段，一个是 ScheduleListFrgment，另一个是 TripHistoryFragment.

现在，当我替换 MyTrips fragment 时，它首先显示 ScheduleListFragment，从服务器加载数据并显示在列表中，它还从服务器加载 tripHistory 的数据。

所以现在我已经给 ScheduleListFragment 的列表项提供了点击事件，所以 onClick 它将 ScheduleListFragment 替换为 PostDetailsFragment。

现在，在我从 PostDetailsFragment 返回后，它显示空 ScheduleListFragment，没有列表。

我想在用户从 PostDetailsFragment 按下时显示列表。

ScheduleListFragment

public class ScheduledTravelFragment extends Fragment implements GetScheduledTripsAsyncTask.GetScheduleTripsCallBack{

    public RecyclerView mRecyclerView_list;
    private ArrayList<Trips> mTripsList;
    private ScheduledTravelAdapter mTripsAdapter;
    public TextView mTextViewData;
    private String mDateTime;
    private SessionData sessionData;

    private RelativeLayout parentLayout;

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


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_scheduled_travel, container, false);


        setUpUI(view);


        return view;
    }
    @Override
    public void onStart()
    {
        super.onStart();

        GetScheduledTripsAsyncTask getScheduledTripsAsyncTask = new GetScheduledTripsAsyncTask(getActivity(),parentLayout,ScheduledTravelFragment.this,ScheduledTravelFragment.this);
        getScheduledTripsAsyncTask.execute(mDateTime,sessionData.getString("api_key",""));
    }

    public void setUpUI(View view)
    {

        mRecyclerView_list = (RecyclerView) view.findViewById(R.id.rv_tripList);
        mTextViewData = (TextView) view.findViewById(R.id.textViewData);
        parentLayout = (RelativeLayout) view.findViewById(R.id.parentPanel);

        mTripsList = new ArrayList<Trips>();
        mTripsAdapter = new ScheduledTravelAdapter(getActivity(),mTripsList, ScheduledTravelFragment.this);
        mRecyclerView_list.setLayoutManager(new LinearLayoutManager(getActivity()));
        mRecyclerView_list.setAdapter(mTripsAdapter);
        mRecyclerView_list.setHasFixedSize(true);
        mRecyclerView_list.setItemViewCacheSize(50);
        mRecyclerView_list.setDrawingCacheEnabled(true);
        mRecyclerView_list.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_HIGH);

        sessionData = new SessionData(getActivity());
        mDateTime = String.valueOf(CommonUtils.getCurrentDateTime());

    }

    @Override
    public void doPostExecute(ArrayList<Trips> list)
    {
        mTripsList.addAll(list);

        mTripsAdapter.notifyDataChanged();

    }


}

ScheduleListAdapter

public class ScheduledTravelAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {


    private Context context;
    private ArrayList<Trips> list;
    private ScheduledTravelFragment tripListFragment;
    static final int TYPE_LOAD_TRIP = 0, TYPE_LOAD_PROGRESS = 1;
    boolean isLoading = false, isMoreDataAvailable = true;
    TransportListAdapter.OnLoadMoreListener loadMoreListener;

    public ScheduledTravelAdapter(Context context, ArrayList<Trips> list,ScheduledTravelFragment tripListFragment) {
        this.context = context;
        this.list = list;
        this.tripListFragment = tripListFragment;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, final int viewType) {

        RecyclerView.ViewHolder viewHolder = null;
        LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        switch (viewType) {

            case TYPE_LOAD_TRIP:
                View v_order_header = inflater.inflate(R.layout.trip_layout, parent, false);
                viewHolder = new TripsHolder(v_order_header);
                break;

        }

        return viewHolder;
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {

        if (position >= getItemCount() - 1 && isMoreDataAvailable && !isLoading && loadMoreListener != null) {
            isLoading = true;
            loadMoreListener.onLoadMore();
        }

        if (getItemViewType(position) == TYPE_LOAD_TRIP) {
            TripsHolder tripsHolder = (TripsHolder) holder;
            retriveAllTrips(tripsHolder, position);
        } else {
        }

    }

    @Override
    public int getItemViewType(int position) {

        Object obj = list.get(position);

        if (obj instanceof Transport) {
            return TYPE_LOAD_TRIP;
        }

        return super.getItemViewType(position);
    }

    @Override
    public int getItemCount() {
        return list.size();
    }


    public void retriveAllTrips(final TripsHolder holder, int position) {


        final Trips data = (Trips) list.get(position);

        final String newDate = CommonUtils.formateDateFromstring("yyyy-MM-dd HH:mm:ss", "dd MMM, yyyy", data.getmDate());


        holder.tv_date.setText(newDate);
        holder.tv_from.setText(data.getmFrom());
        holder.tv_to.setText(data.getmTo());

        //go to post detail fragment

            holder.lay_row.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {

                    Bundle bundle = new Bundle();
                    bundle.putString("pt_id", data.getmPostId());
                    bundle.putString("pt_name", data.getmPostName());
                    bundle.putString("pt_details", data.getmPostDetails());
                    bundle.putString("pt_photo", data.getmImage());
                    bundle.putString("pt_date", data.getmDate());
                    bundle.putString("from", data.getmFrom());
                    bundle.putString("to", data.getmTo());

                    //go to post details screen
                    FragmentManager fragmentManager = tripListFragment.getFragmentManager();
                    PostDetailsFragment fragment = new PostDetailsFragment();
                    fragment.setArguments(bundle);
                    fragmentManager.beginTransaction().replace(R.id.mycontainer, fragment, "POST_DETAILS_FRAGMENT").addToBackStack("O").commit();

                }
            });

 }
    public void notifyDataChanged() {
        notifyDataSetChanged();
        isLoading = false;
    }

}

编辑：

MyTrips 片段：

public class MyTripsFragment extends Fragment {

    private ViewPager viewPager;
    private TabsPagerAdapter mAdapter;
    private CharSequence Titles[]={"Scheduled Travel","Travel History"};
    private int Numboftabs =2;
    private SlidingTabLayout tabs;
    private TabLayout tabLayout;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_my_trips, container, false);

        final Toolbar toolbar = (Toolbar) ((HomeActivity) getActivity()).findViewById(R.id.toolbar);
        ((HomeActivity) getActivity()).setSupportActionBar(toolbar);

        ImageView mLogo = (ImageView) getActivity().findViewById(R.id.imgLogo);
        mLogo.setVisibility(View.GONE);

        TextView title = (TextView) getActivity().findViewById(R.id.textTitle);
        title.setVisibility(View.VISIBLE);
        title.setText(R.string.myTrips);

        mAdapter =  new TabsPagerAdapter(getActivity().getFragmentManager(),Titles,Numboftabs);
        viewPager = (ViewPager)view.findViewById(R.id.pager);

        setupViewPager(viewPager);

        tabLayout = (TabLayout)view.findViewById(R.id.tabs);
        tabLayout.setupWithViewPager(viewPager);

        return view;
    }

    @Override
    public void onResume()
    {
        super.onResume();
    }

    private void setupViewPager(ViewPager viewPager) {
        ViewPagerAdapter adapter = new ViewPagerAdapter(getFragmentManager());
        adapter.addFragment(new ScheduledTravelFragment(), "Scheduled Travel");
        adapter.addFragment(new TravelHistoryFragment(), "Travel History");
        viewPager.setAdapter(adapter);
    }
    class ViewPagerAdapter extends FragmentStatePagerAdapter {
        private final List<Fragment> mFragmentList = new ArrayList<>();
        private final List<String> mFragmentTitleList = new ArrayList<>();

        public ViewPagerAdapter(FragmentManager manager) {
            super(manager);
        }

        @Override
        public Fragment getItem(int position) {
            return mFragmentList.get(position);
        }

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

        public void addFragment(Fragment fragment, String title) {
            mFragmentList.add(fragment);
            mFragmentTitleList.add(title);
        }

        @Override
        public CharSequence getPageTitle(int position) {
            return mFragmentTitleList.get(position);
        }
    }

}

第一次创建的片段标题是mytrips。

在下一个片段更改文本。`

final Toolbar toolbar = (Toolbar) ((HomeActivity) getActivity()).findViewById(R.id.toolbar); ((HomeActivity) getActivity()).setSupportActionBar(toolbar);

    ImageView mLogo = (ImageView)getActivity().findViewById(R.id.imgLogo);
    mLogo.setVisibility(View.GONE);

    TextView title = (TextView) getActivity().findViewById(R.id.textTitle);
    title.setVisibility(View.VISIBLE);
    title.setText(R.string.tripDetails);`

下一个片段的 OnBackpress。 Carry 应用程序徽标设置在我可见的主要片段上。

Answer 1

尝试将所有这些放在 onResume 中：

GetScheduledTripsAsyncTask getScheduledTripsAsyncTask = new GetScheduledTripsAsyncTask(getActivity(),parentLayout,ScheduledTravelFragment.this,ScheduledTravelFragment.this);
        getScheduledTripsAsyncTask.execute(mDateTime,sessionData.getString("api_key",""));

mTripsList = new ArrayList<Trips>();
        mTripsAdapter = new ScheduledTravelAdapter(getActivity(),mTripsList, ScheduledTravelFragment.this);
        mRecyclerView_list.setLayoutManager(new LinearLayoutManager(getActivity()));
        mRecyclerView_list.setAdapter(mTripsAdapter);
        mRecyclerView_list.setHasFixedSize(true);
        mRecyclerView_list.setItemViewCacheSize(50);
        mRecyclerView_list.setDrawingCacheEnabled(true);
        mRecyclerView_list.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_HIGH);

        sessionData = new SessionData(getActivity());
        mDateTime = String.valueOf(CommonUtils.getCurrentDateTime());

Answer 2

你不应该使用替换。为了您的目的，请尝试添加。

fragmentManager
.beginTransaction()
.add(R.id.mycontainer, fragment, "POST_DETAILS_FRAGMENT")
.addToBackStack("O")
.commit();

这样你的最后一个片段保持在它的状态不会改变也不会再次创建。

别忘了让您的下一个片段根布局可点击。这样，如果你点击任何地方，它不会点击底部片段。

android:clickable="true"

另外不要忘记为您的下一个片段提供背景

Answer 3

尝试使用 PostDetailsFragment 作为 ScheduleListFrgment 的子项。这个bug永远不会出现。

getChildFragmentManager().beginTransaction() 和进一步的步骤。

如何在从下一个片段按下的背面显示片段列表？

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