【发布时间】：2014-12-26 06:46:18
【问题描述】：
我有一个应用程序来管理图书收藏（如播放列表）。
我想显示一个带有垂直 RecyclerView 的集合列表，并在每行内显示一个水平 RecyclerView 中的书籍列表。
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 当我将它设置为 wrap_content 时，它什么也不显示。 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。
你知道我做错了什么吗？
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>
书单项：
<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>
这是我的收集适配器：
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();
}
}
最后是 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();
}
}
【问题讨论】：
-
为什么要使用wrap_content来改变layoutmanager的纵横？
-
如果我将 layout_height 设置为一个特定的值（比如说水平布局管理器的元素高度），它只显示垂直布局管理器列表的第一行。
-
但是 recyclerView 有一个内置的滚动视图，所以你可以滚动浏览项目......或者我错过了这里的重点？抱歉试图理解
-
我想滚动浏览收藏项目，但不想滚动内部图书列表（水平方向除外）。像 ExpandableListView 之类的东西。
-
我和你有同样的问题，你现在解决了吗？
标签： android android-layout android-studio android-recyclerview android-support-library