Question

我正在关注此Tutorial，并以某种方式陷入从Firebase检索数据。

我从firebase获取数据，所以我认为这不是问题。

我尝试通过调用

来填充列表

loadData();

这是函数

 public void loadData() {

        for (int i = 0; i <= 20; i++) {
            mDataSet.add(new Schedules("1","Riverview " , "09151050674", "MOA" ,"01/01/18-11:00PM" , "1000"));

        }


    }

它有效！但不知何故，我试图用来自firebase的数据来填充它不起作用！

我的代码片段就在下面

import android.app.Fragment;
import android.content.Context;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;

import com.daimajia.swipe.SwipeLayout;
import com.daimajia.swipe.adapters.RecyclerSwipeAdapter;
import com.daimajia.swipe.util.Attributes;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;

import java.util.ArrayList;
import java.util.List;

import lim.bookings.Dialogs.AddScheduleDialog;
import lim.bookings.DividerItemDecoration;
import lim.bookings.Objects.Schedules;
import lim.bookings.R;


public class ScheduleFragment extends Fragment {

    private List<Schedules> mDataSet;
    private TextView textViewList;
    private RecyclerView recyclerView;
    private FloatingActionButton fab;
    private DatabaseReference databaseSchedule;

    @Override
    public void onStart() {
        super.onStart();
        //attaching value event listener
        databaseSchedule.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {

                //clearing the previous artist list
                mDataSet.clear();

                //iterating through all the nodes
                for (DataSnapshot postSnapshot : dataSnapshot.getChildren()) {
                    //getting artist
                    Schedules schedules = postSnapshot.getValue(Schedules.class);
                    //adding artist to the list
                    mDataSet.add(schedules);
                }

                //creating adapter
                SwipeRecyclerViewAdapter mAdapter = new SwipeRecyclerViewAdapter(getActivity(), mDataSet);


                // Setting Mode to Single to reveal bottom View for one item in List
                // Setting Mode to Mutliple to reveal bottom Views for multile items in List
                (mAdapter).setMode(Attributes.Mode.Single);

                recyclerView.setAdapter(mAdapter);
            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        //Inflate the layout for this fragment_packages
        final View view = inflater.inflate(R.layout.schedule_fragment, container, false);
        fab = view.findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
//                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
//                        .setAction("Action", null).show();
                AddScheduleDialog addScheduleDialog = new AddScheduleDialog(getActivity());
                addScheduleDialog.show();
            }
        });
        databaseSchedule = FirebaseDatabase.getInstance().getReference("Sched");


        initScheduleView(view);

        return view;
    }

    private void initScheduleView(View view){

        recyclerView = view.findViewById(R.id.recycleView);
        textViewList = view.findViewById(R.id.textViewList);

        // Layout Managers:
        recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));

        // Item Decorator:
        recyclerView.addItemDecoration(new DividerItemDecoration(getResources().getDrawable(R.drawable.divider)));

        mDataSet = new ArrayList<>();




        if (mDataSet.isEmpty()) {
            recyclerView.setVisibility(View.INVISIBLE);
            textViewList.setVisibility(View.VISIBLE);

        } else {
            recyclerView.setVisibility(View.VISIBLE);
            textViewList.setVisibility(View.GONE);
        }


        // Creating Adapter object


        /* Scroll Listeners */
        recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
                super.onScrollStateChanged(recyclerView, newState);
                Log.e("RecyclerView", "onScrollStateChanged");
            }

            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);
            }
        });
    }




    private class SwipeRecyclerViewAdapter extends RecyclerSwipeAdapter<SwipeRecyclerViewAdapter.SimpleViewHolder> {


        private Context mContext;
        private List<Schedules> schedulesList;

        public SwipeRecyclerViewAdapter(Context context, List<Schedules> objects) {
            this.mContext = context;
            this.schedulesList = objects;
        }

        @Override
        public SimpleViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.swipe_row_item, parent, false);
            return new SimpleViewHolder(view);
        }

        @Override
        public void onBindViewHolder(final SimpleViewHolder viewHolder, final int position) {
            final Schedules item = schedulesList.get(position);

            viewHolder.tvName.setText("Guest Name:"+item.getName());
            viewHolder.tvTime.setText("Time:"+ item.getDateTime());
            viewHolder.tvLocation.setText("Pick Up:"+item.getAddressFrom());
            viewHolder.tvLocation2.setText("Destination:"+item.getAddressTo());
            viewHolder.tvPrice.setText("Price:"+item.getPrice());



            viewHolder.swipeLayout.setShowMode(SwipeLayout.ShowMode.PullOut);

            // Drag From Left
            viewHolder.swipeLayout.addDrag(SwipeLayout.DragEdge.Left, viewHolder.swipeLayout.findViewById(R.id.bottom_wrapper1));

            // Drag From Right
            viewHolder.swipeLayout.addDrag(SwipeLayout.DragEdge.Right, viewHolder.swipeLayout.findViewById(R.id.bottom_wrapper));


            // Handling different events when swiping
            viewHolder.swipeLayout.addSwipeListener(new SwipeLayout.SwipeListener() {
                @Override
                public void onClose(SwipeLayout layout) {
                    //when the SurfaceView totally cover the BottomView.
                }

                @Override
                public void onUpdate(SwipeLayout layout, int leftOffset, int topOffset) {
                    //you are swiping.
                }

                @Override
                public void onStartOpen(SwipeLayout layout) {

                }

                @Override
                public void onOpen(SwipeLayout layout) {
                    //when the BottomView totally show.
                }

                @Override
                public void onStartClose(SwipeLayout layout) {

                }

                @Override
                public void onHandRelease(SwipeLayout layout, float xvel, float yvel) {
                    //when user's hand released.
                }
            });

        /*viewHolder.swipeLayout.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                if ((((SwipeLayout) v).getOpenStatus() == SwipeLayout.Status.Close)) {
                    //Start your activity

                    Toast.makeText(mContext, " onClick : " + item.getName() + " \n" + item.getContactNum(), Toast.LENGTH_SHORT).show();
                }

            }
        });*/

            viewHolder.swipeLayout.getSurfaceView().setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Toast.makeText(mContext, " onClick : " + item.getName() + " \n" + item.getContactNum(), Toast.LENGTH_SHORT).show();
                }
            });


            viewHolder.tvDone.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    Toast.makeText(v.getContext(), "Clicked on Map " + viewHolder.tvName.getText().toString(), Toast.LENGTH_SHORT).show();
                }
            });


            viewHolder.tvShare.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {

                    Toast.makeText(view.getContext(), "Clicked on Share " + viewHolder.tvName.getText().toString(), Toast.LENGTH_SHORT).show();
                }
            });

            viewHolder.tvEdit.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {

                    Toast.makeText(view.getContext(), "Clicked on Edit  " + viewHolder.tvName.getText().toString(), Toast.LENGTH_SHORT).show();
                }
            });


            viewHolder.tvDelete.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    mItemManger.removeShownLayouts(viewHolder.swipeLayout);
                    schedulesList.remove(position);
                    notifyItemRemoved(position);
                    notifyItemRangeChanged(position, schedulesList.size());
                    mItemManger.closeAllItems();
                    Toast.makeText(view.getContext(), "Deleted " + viewHolder.tvName.getText().toString(), Toast.LENGTH_SHORT).show();
                }
            });


            // mItemManger is member in RecyclerSwipeAdapter Class
            mItemManger.bindView(viewHolder.itemView, position);

        }

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

        @Override
        public int getSwipeLayoutResourceId(int position) {
            return R.id.swipe;
        }


        //  ViewHolder Class

        public class SimpleViewHolder extends RecyclerView.ViewHolder {
            SwipeLayout swipeLayout;
            TextView tvName;
            TextView tvTime,tvLocation,tvLocation2;
            TextView tvDelete;
            TextView tvEdit;
            TextView tvShare;
            TextView tvDone;
            TextView tvPrice;

            public SimpleViewHolder(View itemView) {
                super(itemView);
                swipeLayout =  itemView.findViewById(R.id.swipe);
                tvName =  itemView.findViewById(R.id.tvName);
                tvTime = itemView.findViewById(R.id.tvTime);
                tvLocation = itemView.findViewById(R.id.tvLocation);
                tvLocation2 = itemView.findViewById(R.id.tvLocation2);
                tvPrice = itemView.findViewById(R.id.tvPrice);
                tvDelete =  itemView.findViewById(R.id.tvDelete);
                tvEdit = itemView.findViewById(R.id.tvEdit);
                tvShare =  itemView.findViewById(R.id.tvShare);
                tvDone =  itemView.findViewById(R.id.tvDone);


            }
        }
    }
}

Answer 1

我认为您应该在react-dom中设置recyclerview适配器。在initScheduleView()中，获取数据列表，将其传递到适配器并调用databaseSchedule.addValueEventListener(new ...)。

对于性能问题，请使用adapter.notifyDataSetChanged()代替DiffUtil。

修改

notifyDataSetChanged()

...希望它可以帮助你。

Android List无法填充数据，但可以从firebase检索数据

1 个答案: