Question

在我的博客应用中，发布包含（标题，说明和图片）。无法从Firebase检索数据并使用RecyclerView适配器显示它。我无法确定问题所在。代码是： -

public class MainActivity extends AppCompatActivity {

    private RecyclerView mBlogList;

    private DatabaseReference mDatabase;

    private static final String TAG = "MainActivity";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mDatabase = FirebaseDatabase.getInstance().getReference().child("Blog");

        mBlogList = (RecyclerView)findViewById(R.id.blog_list);
        mBlogList.setHasFixedSize(true);
        mBlogList.setLayoutManager(new LinearLayoutManager(this));

    }

    @Override
    protected void onStart() {
        super.onStart();
        Query query = FirebaseDatabase.getInstance()
                .getReference()
                .child("Blog_Images");

        FirebaseRecyclerOptions<Blog> options =
                new FirebaseRecyclerOptions.Builder<Blog>()
                        .setQuery(query, Blog.class)
                        .build();

        FirebaseRecyclerAdapter<Blog, BlogViewHolder> firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<Blog, BlogViewHolder>
                (options) {
            @Override
            public BlogViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
                View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.blog_row,parent,false);
                return new BlogViewHolder(view);
            }
            @Override
            protected void onBindViewHolder(@NonNull BlogViewHolder holder, int position, @NonNull Blog model) {
                holder.setTitle(model.getTitle());
                holder.setDescription(model.getDescription());
                holder.setImage(getApplicationContext(),model.getImage());
            }
        };
        mBlogList.setAdapter(firebaseRecyclerAdapter);
    }

    public class BlogViewHolder extends RecyclerView.ViewHolder {

        View mView;

        public BlogViewHolder(View itemView) {
            super(itemView);
            mView = itemView;
        }

        public void setTitle(String title)
        {
            TextView post_title = (TextView) mView.findViewById(R.id.post_title);
            post_title.setText(title);
        }

        public void setDescription(String desc)
        {
            TextView post_desc = (TextView) mView.findViewById(R.id.post_desc);
            post_desc.setText(desc);
        }

        public void setImage(Context ctx, String image)
        {
            ImageView post_image = (ImageView) mView.findViewById(R.id.post_image);
            //Picasso.with(ctx).load(image).into(post_image);
            Glide.with(MainActivity.this).load(image).into(post_image);
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main_menu,menu);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (item.getItemId() == R.id.action_add)
        {
            startActivity(new Intent(MainActivity.this,PostActivity.class));
        }
        return super.onOptionsItemSelected(item);
    }
}

我的MainActivity只是空白。我不知道问题出在哪里。我尝试了ValueEventListener，addValueEventListener但没有结果，事实上它在LOGCAT中说：

无法找到布局，跳过此

Answer 1

在聊天中与OP交谈后，他导出了JSON，父节点的名称为Blog，而不是Blog_images，所以我告诉他改变这个：

 Query query = FirebaseDatabase.getInstance()
            .getReference()
            .child("Blog_Images");

进入这个：

 Query query = FirebaseDatabase.getInstance()
            .getReference()
            .child("Blog");

无法在FirebaseRecyclerAdapter（Android Studio）中使用自定义布局

1 个答案: