由于某种原因，我的 inflate 没有显示 xml 文件，这是为什么呢？

Question

由于某种原因，我的 inflate 没有显示 xml 文件？

我的家.java：

package com.example.soulforge.fragments;

import android.os.Bundle;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.example.soulforge.R;
import com.example.soulforge.adapter.HomeAdapter;
import com.example.soulforge.model.HomeModel;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.firestore.CollectionReference;
import com.google.firebase.firestore.DocumentReference;
import com.google.firebase.firestore.EventListener;
import com.google.firebase.firestore.FirebaseFirestore;
import com.google.firebase.firestore.FirebaseFirestoreException;
import com.google.firebase.firestore.QueryDocumentSnapshot;
import com.google.firebase.firestore.QuerySnapshot;

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


public class Home extends Fragment {

    private RecyclerView recyclerView;


    HomeAdapter adapter;

    private List<HomeModel> list;

    private FirebaseUser user;

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


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

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

        init(view);

        list = new ArrayList<>();
        adapter = new HomeAdapter(list, getContext());
        recyclerView.setAdapter(adapter);

        loadDataFromFirestore();
    }

    private void init(View view) {

        Toolbar toolbar = view.findViewById(R.id.toolbar);
        if (getActivity() != null)
            ((AppCompatActivity) getActivity()).setSupportActionBar(toolbar);

        recyclerView = view.findViewById(R.id.recyclerView);
        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));

        FirebaseAuth auth = FirebaseAuth.getInstance();
        user = auth.getCurrentUser();
    }

    public void loadDataFromFirestore() {
        CollectionReference reference = FirebaseFirestore.getInstance().collection("Users")
                .document(user.getUid())
                .collection("Post Images");

        reference.addSnapshotListener(new EventListener<QuerySnapshot>() {
            @Override
            public void onEvent(@Nullable QuerySnapshot value, @Nullable FirebaseFirestoreException error) {
                if (error != null) {
                    Log.e("Error: ", error.getMessage());
                    return;
                }
                if (value == null)
                    return;
                for (QueryDocumentSnapshot snapshot : value) {
                    if (!snapshot.exists())
                        return;

                    HomeModel model = snapshot.toObject(HomeModel.class);
                    list.add(new HomeModel(
                            model.getUserName(),
                            model.getProfileImage(),
                            model.getImageUrl(),
                            model.getUid(),
                            model.getComments(),
                            model.getDescription(),
                            model.getId(),
                            model.getTimestamp(),
                            model.getLikeCount()
                    ));
                }
                adapter.notifyDataSetChanged();
            }
        });

    }
}

还有我的 HomeAdapter.java：

package com.example.soulforge.adapter;

import android.content.Context;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import com.bumptech.glide.Glide;
import com.example.soulforge.R;
import com.example.soulforge.model.HomeModel;
import com.google.firebase.firestore.EventListener;
import com.google.firebase.firestore.QuerySnapshot;

import java.util.List;
import java.util.Random;

import de.hdodenhof.circleimageview.CircleImageView;


public class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.HomeHolder>{

    private List<HomeModel> list;
    Context context;

    public HomeAdapter(List<HomeModel> list, Context context) {
        this.list = list;
        this.context = context;
    }



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

    }


    @Override
    public void onBindViewHolder(@NonNull HomeHolder holder, int position) {

        holder.userNameTv.setText(list.get(position).getUserName());
        holder.timeTv.setText(""+list.get(position).getTimestamp());


        int count = list.get(position).getLikeCount();
        if(count ==0){
            holder.likeCountTv.setVisibility(View.INVISIBLE);
        }else if (count == 1){
            holder.likeCountTv.setText(count + " like");
        }else{
            holder.likeCountTv.setText(count + " likes");
        }

        holder.descriptionTv.setText(list.get(position).getDescription());


        Random random = new Random();

        int color = Color.argb(255, random.nextInt(256), random.nextInt(256), random.nextInt(256));

        Glide.with(context.getApplicationContext())
                .load(list.get(position).getProfileImage())
                .placeholder(R.drawable.ic_person)
                .timeout(6500)
                .into(holder.profileImage);

        Glide.with(context.getApplicationContext())
                .load(list.get(position).getImageUrl())
                .placeholder(new ColorDrawable(color))
                .timeout(7000)
                .into(holder.imageView);

    }

    @Override
    public int getItemCount() {

        return list.size();
    }

    static class HomeHolder extends RecyclerView.ViewHolder{
        private CircleImageView profileImage;
        private TextView userNameTv, timeTv, likeCountTv, descriptionTv;
        private ImageView imageView;
        private ImageButton likeBtn, commentBtn, shareBtn;

        public HomeHolder(@NonNull View itemView) {
            super(itemView);

            profileImage = itemView.findViewById(R.id.profileImage);
            imageView = itemView.findViewById(R.id.imageView);
            userNameTv = itemView.findViewById(R.id.nameTv);
            timeTv = itemView.findViewById(R.id.timeTv);
            likeCountTv = itemView.findViewById(R.id.likeCountTv);
            likeBtn = itemView.findViewById(R.id.likeBtn);
            commentBtn = itemView.findViewById(R.id.commentBtn);
            shareBtn = itemView.findViewById(R.id.shareBtn);
            descriptionTv = itemView.findViewById(R.id.descTv);


        }
    }
}

所以我想知道我做了你应该做的一切，但是它没有在我的 fragment_home 上显示我的 home_items.xml。它仅显示 fragment_home 仅缺少 home_items。有没有办法帮助解决这个问题，我在这里被困了好几天，想尝试解决这个问题:(

Answer 1

可能是错误的，因为我没有检查详细信息。您可以尝试将 adapter.notifydataset 向上移动一个元素（即在 } 之前）。可能是错误的，但它似乎没有通知数据集更改它必须在正确的位置在 for 快照循环内。可能又错了

Answer 2

请移动

    adapter = new HomeAdapter(list, getContext());
    recyclerView.setAdapter(adapter);

在for循环结束位置的上方但下方

    adapter.notifydatachange();

因为您首先将列表传递给适配器，然后从 firebase 获取数据并始终在活动/片段的 onStart 中调用您的 loadDataFromFirestore() 这种类型的方法，因为每次当您的活动/片段从后台返回时都会执行 onstart停止后的前台，onCreate 仅在您的活动/片段创建时调用一次。