RecyclerView条目不显示问题排查求助

在Android开发中遇到RecyclerView条目不显示的问题，页面完全空白，已做以下排查：

• folderList的长度为2
• Adapter的getItemCount()返回值为2
• 尝试重新创建Adapter，问题依然存在

相关代码如下：

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 初始化代码 #

FolderListAdapter adapter = new FolderListAdapter(this, folderList);

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

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

RecyclerView 布局XML（预览配置） #

<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" />

条目布局 folder_view.xml #

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <com.google.android.material.imageview.ShapeableImageView
        android:id="@+id/folder_image_view"
        android:layout_width="150dp"
        android:layout_height="150dp"
        android:layout_marginTop="10dp"
        android:scaleType="centerCrop"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:background="?android:attr/selectableItemBackground"
        app:shapeAppearanceOverlay="@style/ShapeAppearanceOverlay.App.CornerSize50Percent"
        tools:srcCompat="@tools:sample/backgrounds/scenic" />

    <TextView
        android:id="@+id/folder_name_text_view"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="4dp"
        android:text="Camera"
        android:textColor="@android:color/primary_text_light"
        android:textSize="16sp"
        app:layout_constraintEnd_toEndOf="@+id/folder_image_view"
        app:layout_constraintStart_toStartOf="@+id/folder_image_view"
        app:layout_constraintTop_toBottomOf="@+id/folder_image_view" />

    <TextView
        android:id="@+id/folder_items_count_text_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="600 Items"
        android:textSize="12sp"
        app:layout_constraintStart_toStartOf="@+id/folder_name_text_view"
        app:layout_constraintTop_toBottomOf="@+id/folder_name_text_view" />
</androidx.constraintlayout.widget.ConstraintLayout>

页面布局 activity_folder.xml #

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ui.addFiles.FoldersActivity">

    <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:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

运行效果 #

求帮忙排查为何页面没有显示任何内容。

内容的提问来源于stack exchange，提问作者Hammad Zafar Bawara