回收人员查看项目不显示

Question

FolderListAdapter代码

public class FolderListAdapter extends RecyclerView.Adapter<FolderListAdapter.myViewHolder> {
    private final Context context;
    private final ArrayList<Folder> folderList;

    public FolderListAdapter(Context context, ArrayList<Folder> folderList) {
        this.context = context;
        this.folderList = folderList;
    }

    @NonNull
    @Override
    public myViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(context).inflate(R.layout.folder_view, parent, false);
        return new myViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull myViewHolder holder, int position) {
        Folder folder = folderList.get(position);
        Glide.with(context).load(folder.getFolder()).into(holder.imageView);
        holder.folder_name.setText(folder.getFolder().getName());
        holder.folder_item_count.setText(folder.getFilesList().size() + " Items");
    }

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

    public class myViewHolder extends RecyclerView.ViewHolder {
        private final ShapeableImageView imageView;
        private final TextView folder_name;
        private final TextView folder_item_count;
        public myViewHolder(@NonNull View itemView) {
            super(itemView);

            imageView = itemView.findViewById(R.id.folder_image_view);
            folder_name = itemView.findViewById(R.id.folder_name_text_view);
            folder_item_count = itemView.findViewById(R.id.folder_items_count_text_view);
        }
    }
}

RecyclerView的Mainactive代码

FolderListAdapter adapter = new FolderListAdapter(this, folderList);

RecyclerView recyclerView = binding.folderRecyclerView;
recyclerView.setAdapter(adapter);

recyclerView.setLayoutManager(new GridLayoutManager(this, 2));

回收器视图的XML代码

<androidx.recyclerview.widget.RecyclerView
        android:id="@+id/folder_recyclerView"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layoutManager="androidx.recyclerview.widget.GridLayoutManager"
        app:spanCount="2"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:listitem="@layout/folder_view" />

• folderList的大小为2
• 我还检查了适配器的大小。它也是2，我不知道我在哪里犯了错误，为什么它现在在活动中什么都没有显示

Answer 1

在xml中，将属性设置为android:layout\u width=“0dp”和android:layout\u height=“0dp”

在设置适配器之前，在您的主活动中，将代码集设置为布局管理器。代码是这样的：

//Defining RecyclerView and setting LayoutManager
RecyclerView recyclerView = binding.folderRecyclerView;
FolderListAdapter adapter = new FolderListAdapter(this, folderList);

//Setting up Adapter
recyclerView.setLayoutManager(new GridLayoutManager(this, 2));
recyclerView.setAdapter(adapter);