我有一个管理书籍收藏（例如播放列表）的应用程序。
我想在垂直的RecyclerView中显示收藏列表，在每行中显示水平的RecyclerView中的图书列表。
当我将内部水平RecyclerView的layout_height设置为300dp时，它可以正确显示，但是当我将其设置为wrap_content时，它不显示任何内容。 我需要使用wrap_content，因为我希望能够以编程方式更改布局管理器以在垂直和水平显示之间切换。
你知道我在做什么错吗？
我的片段布局：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/white">
<com.twibit.ui.view.CustomSwipeToRefreshLayout
android:id="@+id/swipe_container"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.v7.widget.RecyclerView
android:id="@+id/shelf_collection_listview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingTop="10dp"/>
</LinearLayout>
</com.twibit.ui.view.CustomSwipeToRefreshLayout>
</LinearLayout>
集合元素布局：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#FFF">
<!-- Simple Header -->
</RelativeLayout>
<FrameLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="@string/empty_collection"
android:id="@+id/empty_collection_tv"
android:visibility="gone"
android:gravity="center"/>
<android.support.v7.widget.RecyclerView
android:id="@+id/collection_book_listview"
android:layout_width="match_parent"
android:layout_height="wrap_content"/> <!-- android:layout_height="300dp" -->
</FrameLayout>
</LinearLayout>
图书清单项目：
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="180dp"
android:layout_height="220dp"
android:layout_gravity="center">
<ImageView
android:id="@+id/shelf_item_cover"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:maxWidth="150dp"
android:maxHeight="200dp"
android:src="@drawable/placeholder"
android:contentDescription="@string/cover"
android:adjustViewBounds="true"
android:background="@android:drawable/dialog_holo_light_frame"/>
</FrameLayout>
这是我的收藏适配器：
private class CollectionsListAdapter extends RecyclerView.Adapter<CollectionsListAdapter.ViewHolder> {
private final String TAG = CollectionsListAdapter.class.getSimpleName();
private Context mContext;
// Create the ViewHolder class to keep references to your views
class ViewHolder extends RecyclerView.ViewHolder {
private final TextView mHeaderTitleTextView;
private final TextView mHeaderCountTextView;
private final RecyclerView mHorizontalListView;
private final TextView mEmptyTextView;
public ViewHolder(View view) {
super(view);
mHeaderTitleTextView = (TextView) view.findViewById(R.id.collection_header_tv);
mHeaderCountTextView = (TextView) view.findViewById(R.id.collection_header_count_tv);
mHorizontalListView = (RecyclerView) view.findViewById(R.id.collection_book_listview);
mEmptyTextView = (TextView) view.findViewById(R.id.empty_collection_tv);
}
}
public CollectionsListAdapter(Context context) {
mContext = context;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int i) {
Log.d(TAG, "CollectionsListAdapter.onCreateViewHolder(" + parent.getId() + ", " + i + ")");
// Create a new view by inflating the row item xml.
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.shelf_collection, parent, false);
// Set the view to the ViewHolder
ViewHolder holder = new ViewHolder(v);
holder.mHorizontalListView.setHasFixedSize(false);
holder.mHorizontalListView.setHorizontalScrollBarEnabled(true);
// use a linear layout manager
LinearLayoutManager mLayoutManager = new LinearLayoutManager(mContext);
mLayoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
holder.mHorizontalListView.setLayoutManager(mLayoutManager);
return holder;
}
@Override
public void onBindViewHolder(ViewHolder holder, int i) {
Log.d(TAG, "CollectionsListAdapter.onBindViewHolder(" + holder.getPosition() + ", " + i + ")");
Collection collection = mCollectionList.get(i);
Log.d(TAG, "Collection : " + collection.getLabel());
holder.mHeaderTitleTextView.setText(collection.getLabel());
holder.mHeaderCountTextView.setText("" + collection.getBooks().size());
// Create an adapter if none exists
if (!mBookListAdapterMap.containsKey(collection.getCollectionId())) {
mBookListAdapterMap.put(collection.getCollectionId(), new BookListAdapter(getActivity(), collection));
}
holder.mHorizontalListView.setAdapter(mBookListAdapterMap.get(collection.getCollectionId()));
}
@Override
public int getItemCount() {
return mCollectionList.size();
}
}
最后，Book适配器：
private class BookListAdapter extends RecyclerView.Adapter<BookListAdapter.ViewHolder> implements View.OnClickListener {
private final String TAG = BookListAdapter.class.getSimpleName();
// Create the ViewHolder class to keep references to your views
class ViewHolder extends RecyclerView.ViewHolder {
public ImageView mCoverImageView;
public ViewHolder(View view) {
super(view);
mCoverImageView = (ImageView) view.findViewById(R.id.shelf_item_cover);
}
}
@Override
public void onClick(View v) {
BookListAdapter.ViewHolder holder = (BookListAdapter.ViewHolder) v.getTag();
int position = holder.getPosition();
final Book book = mCollection.getBooks().get(position);
// Click on cover image
if (v.getId() == holder.mCoverImageView.getId()) {
downloadOrOpenBook(book);
return;
}
}
private void downloadOrOpenBook(final Book book) {
// do stuff
}
private Context mContext;
private Collection mCollection;
public BookListAdapter(Context context, Collection collection) {
Log.d(TAG, "BookListAdapter(" + context + ", " + collection + ")");
mCollection = collection;
mContext = context;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int i) {
Log.d(TAG, "onCreateViewHolder(" + parent.getId() + ", " + i + ")");
// Create a new view by inflating the row item xml.
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.shelf_grid_item, parent, false);
// Set the view to the ViewHolder
ViewHolder holder = new ViewHolder(v);
holder.mCoverImageView.setOnClickListener(BookListAdapter.this); // Download or Open
holder.mCoverImageView.setTag(holder);
return holder;
}
@Override
public void onBindViewHolder(ViewHolder holder, int i) {
Log.d(TAG, "onBindViewHolder(" + holder.getPosition() + ", " + i + ")");
Book book = mCollection.getBooks().get(i);
ImageView imageView = holder.mCoverImageView;
ImageLoader.getInstance().displayImage(book.getCoverUrl(), imageView);
}
@Override
public int getItemCount() {
return mCollection.getBooks().size();
}
}