我有一个不显示任何项目的RecyclerView。最初它是空的,但后来我添加了项目并调用notifyDatasetChanged()。调用getItemCount()并返回25,onBindViewHolder被调用3次并正确设置视图。
public AlbumListAdapter(FacebookActivity activity, long pageId, OnItemClickListener listener){
this.listener = listener;
this.inflater = LayoutInflater.from(activity);
this.service = new PagedGraphService<Album>(String.format("https://graph.facebook.com/%d/albums", pageId),
new PagedGraphService.ServiceUpdateListener() {
@Override
public void dataUpdated() {
notifyDataSetChanged();
}
@Override
public void endReached() {
}
},
new TypeToken<PagedGraphService.GraphResponse<Album>>(){}.getType());
}
@Override
public AlbumHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
return new AlbumHolder(inflater.inflate(R.layout.photo_album_list_card, viewGroup, false));
}
@Override
public void onBindViewHolder(AlbumHolder viewHolder, int i) {
viewHolder.setAlbum(service.get(i));
}
@Override
public int getItemCount() {
return service.getLoadedCount();
}
它的要点。该服务包含一个专辑列表,并通过调用dataUpdated()和endReached()通知适配器更改。
更多代码:
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
RecyclerView view = (RecyclerView) inflater.inflate(R.layout.recycler, container, false);
view.setLayoutManager(new LinearLayoutManager(activity, LinearLayoutManager.VERTICAL, false));
view.setHasFixedSize(false);
AlbumListAdapter adapter = new AlbumListAdapter(activity, FacebookActivity.PSM_PAGE_ID, this);
view.setAdapter(adapter);
return view;
}
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.RecyclerView
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
</android.support.v7.widget.RecyclerView>
更多代码:
活动布局
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">
<include layout="@layout/toolbar"/>
<FrameLayout
android:id="@+id/content"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
列出项目布局:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/album_list_title"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</android.support.v7.widget.CardView>
列表布局:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.RecyclerView
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
</android.support.v7.widget.RecyclerView>
我一直在把代码戳了几个小时,我不知道它为什么不起作用
答案 0 :(得分:21)
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">
<include layout="@layout/toolbar"/>
<FrameLayout
android:id="@+id/content"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
LinearLayout
的默认方向是水平的,工具栏的宽度是match_parent
,因此我的内容不在屏幕上。这可能是Android上最流行的错误之一,这就是为什么你会收到警告,但是include
必须隐藏它。