Android 带有gridlayoutmanager的FirebaseRecyclerAdapter

我让recyclerview接收来自firebase的数据，我想让上传的最后一个项目成为列表中的第一个项目。我使用GridLayoutManager，想显示一张带有文本的图片，所有这些都很好，但我想让它们像instagram一样有序，有人知道这样的事情吗

这是我的代码

public class ItemsUser extends Fragment {

private View mMainView;
private RecyclerView mUsersList;
private String user_id;

private DatabaseReference mUserDatabase;
private FirebaseRecyclerAdapter<ItemRecycleview,UserRecycleView> firebaseRecyclerAdapter;
private DatabaseReference mDatabaseReference;
private FirebaseListAdapter<ItemRecycleview> firebaseListAdapter;

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


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

    mUsersList = (RecyclerView) mMainView.findViewById(R.id.recyclerView_profile);
    mUsersList.setHasFixedSize(true);
    mUsersList.setLayoutManager(new GridLayoutManager(getActivity(),3));

    ProfileUser activity = (ProfileUser) getActivity();
    user_id = activity.getMyData();

    mDatabaseReference = FirebaseDatabase.getInstance().getReference();

    mUserDatabase = FirebaseDatabase.getInstance().getReference().child("Users_photos").child(user_id);
    mUserDatabase.keepSynced(true);
    return mMainView;
}
@Override
public void onStart() {
    super.onStart();
    firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<ItemRecycleview, UserRecycleView>(
            ItemRecycleview.class,
            R.layout.recycleview_item,
            UserRecycleView.class,
            mUserDatabase
    ) {


        @Override
        protected void populateViewHolder(UserRecycleView viewHolder, ItemRecycleview model, int position) {

            viewHolder.setImageName(model.getImageName());
            viewHolder.setImageURL(model.getImageURL(),getContext());

            viewHolder.mView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    String key = firebaseRecyclerAdapter.getRef(mUsersList.getChildLayoutPosition(v)).getKey();
                    Intent imageIntent = new Intent(getActivity(), ImageActivity.class);
                    imageIntent.putExtra("imageKey",key);
                    imageIntent.putExtra("user_id",user_id);
                    startActivity(imageIntent);
                }
            });

        }


    };
    mUsersList.setAdapter(firebaseRecyclerAdapter);
}

public static class UserRecycleView extends RecyclerView.ViewHolder {
    View mView;

    public UserRecycleView(View itemView) {
        super(itemView);
        mView = itemView;

    }
    public void setImageName(String imageName){

        TextView userNameView = (TextView) mView.findViewById(R.id.ImageNameTextView);
        userNameView.setText(imageName);

    }
    public void setImageURL(final String imageURL,final Context ctx){

        final ImageView userImageView = (ImageView) mView.findViewById(R.id.imageView);
        Picasso.with(ctx).load(imageURL).networkPolicy(NetworkPolicy.OFFLINE).into(userImageView, new Callback() {
            @Override
            public void onSuccess() {

            }

            @Override
            public void onError() {
                Picasso.with(ctx).load(imageURL).into(userImageView);
            }
        });

    }
}

---

}

您是否尝试过使用setReverseLayout（）方法将第一个元素设置为列表中的最后一个元素

GridLayoutManager mLayoutManager = new GridLayoutManager(getActivity(),3);
mLayoutManager.setReverseLayout(true);
mLayoutManager.setStackFromEnd(true);
mUsersList.setLayoutManager(mLayoutManager);

---

嘿，伙计们，我刚找到答案：D

您只需在firebaseRecyclerAdapter中添加此方法

这是：

firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<ItemRecycleview, UserRecycleView>(
            ItemRecycleview.class,
            R.layout.recycleview_item,
            UserRecycleView.class,
            mUserDatabase
    ) {
        @Override
        public ItemRecycleview getItem(int position) {
            return super.getItem(getItemCount() - 1 - position);
        }

        @Override
        protected void populateViewHolder(UserRecycleView viewHolder, ItemRecycleview model, int position) {

            viewHolder.setImageName(model.getImageName());
            viewHolder.setImageURL(model.getImageURL(),getContext());

            viewHolder.mView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    String key = firebaseRecyclerAdapter.getRef(mUsersList.getChildLayoutPosition(v)).getKey();
                    Intent imageIntent = new Intent(getActivity(), ImageActivity.class);
                    imageIntent.putExtra("imageKey",key);
                    imageIntent.putExtra("user_id",user_id);
                    startActivity(imageIntent);
                }
            });

        }


    };

firebaseRecyclerAdapter=新的firebaseRecyclerAdapter(
ItemRecycleview.class，
R.layout.recycleview_项目，
UserRecycleView.class，
博物馆数据库
) {
@凌驾
公共项回收查看getItem（内部位置）{
返回super.getItem（getItemCount（）-1-位置）；
}
@凌驾
受保护的void populateViewHolder（UserRecycleView视图持有人、ItemRecycleview模型、int位置）{
setImageName（model.getImageName（））；
setImageURL（model.getImageURL（），getContext（））；
viewHolder.mView.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
String key=firebaseRecyclerAdapter.getRef（muserList.getChildLayoutPosition（v））.getKey（）；
Intent-imageIntent=新的意图（getActivity（），ImageActivity.class）；
imageIntent.putExtra（“imageKey”，key）；
imageIntent.putExtra（“用户id”，用户id）；
星触觉（imageIntent）；
}
});
}
};

---

这样就可以完成了

所以你要获取一个数组，该数组将被设置到列表适配器？是的，没错，我希望上传的最后一个项目是第一个位置。你能理解我吗！您的代码是否有一个数组循环，其中所有数据都显示在列表视图中？如果是，你能把它贴在这里吗？不，这是所有的代码逻辑很简单。。只需在显示结果时反转数组即可。也就是说，从下到上显示数组，for循环等于数组的大小，每次执行时—而不是++。明白了吗？是的，我试过了，但它显示了错误：GridLayoutManager不支持从末尾堆栈。考虑使用反向布局应该是一个评论

firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<ItemRecycleview, UserRecycleView>(
            ItemRecycleview.class,
            R.layout.recycleview_item,
            UserRecycleView.class,
            mUserDatabase
    ) {
        @Override
        public ItemRecycleview getItem(int position) {
            return super.getItem(getItemCount() - 1 - position);
        }

        @Override
        protected void populateViewHolder(UserRecycleView viewHolder, ItemRecycleview model, int position) {

            viewHolder.setImageName(model.getImageName());
            viewHolder.setImageURL(model.getImageURL(),getContext());

            viewHolder.mView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    String key = firebaseRecyclerAdapter.getRef(mUsersList.getChildLayoutPosition(v)).getKey();
                    Intent imageIntent = new Intent(getActivity(), ImageActivity.class);
                    imageIntent.putExtra("imageKey",key);
                    imageIntent.putExtra("user_id",user_id);
                    startActivity(imageIntent);
                }
            });

        }


    };