我正在尝试从模板中将卡片视图添加到我的应用程序中，它已经正常工作，我正在理解，从这个模板中学习和开发，我想我理解它，但显然不是。
当我尝试将其添加到我的应用程序时，我会收到有关recyclerview的一些问题，我正在尝试进行预处理
我的相关主要代码是：
public class MainActivity extends ActionBarActivity
implements NavigationDrawerCallbacks {
(...)
private List<Anime> items = new ArrayList<>();
private RecyclerView recycler;
private RecyclerView.Adapter adapter;
private RecyclerView.LayoutManager lManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mToolbar = (Toolbar) findViewById(R.id.toolbar_actionbar);
setSupportActionBar(mToolbar);
mNavigationDrawerFragment = (NavigationDrawerFragment)
getFragmentManager().findFragmentById(R.id.fragment_drawer);
// Set up the drawer.
mNavigationDrawerFragment.setup(R.id.fragment_drawer, (DrawerLayout) findViewById(R.id.drawer), mToolbar);
coordinates = new String[3];
coordinates[0]="";coordinates[1]="";coordinates[2]="";
location = null;
textViewTitulo = (TextView) findViewById(R.id.textViewCoordinates);
//this line is the SOLUTION
recicle();
}
(...)
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
(...)
items.add(new Anime(R.drawable.iamhere, "You are at:", "lat. 4.59 long. 67.9 alt. 0.0"));
recicle();
}
public void recicle() {
//Obtaining the recicler
recicler = (RecyclerView) findViewById(R.id.reciclador);
recicler.setHasFixedSize(true);
// Usar un administrador para LinearLayout
lManager = new LinearLayoutManager(this);
recycler.setLayoutManager(lManager);
// Crear un nuevo adaptador
adapter = new AnimeAdapter(items);
recycler.setAdapter(adapter);
}
Anime类只包含一个int和两个字符串作为atruibutes
编译好，但我认为问题出在布局上。我有一个导航抽屉片段，我几乎可以肯定我的问题是管理XML中片段中的recyclerView。这是我的主要XML：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent"
android:layout_height="match_parent">
<include android:id="@+id/toolbar_actionbar" layout="@layout/toolbar_default"
android:layout_width="match_parent" android:layout_height="wrap_content" />
<android.support.v4.widget.DrawerLayout android:id="@+id/drawer"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent"
android:layout_below="@+id/toolbar_actionbar">
<FrameLayout android:id="@+id/container" android:layout_width="match_parent"
android:clickable="true" android:layout_height="match_parent" >
<!---This is the RecyclerView at hand -->
<android.support.v7.widget.RecyclerView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/reciclador"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="3dp"
android:scrollbars="vertical" />
</FrameLayout>
<!-- android:layout_marginTop="?android:attr/actionBarSize"-->
<fragment android:id="@+id/fragment_drawer"
android:name="com.example.jesus.myapplication.NavigationDrawerFragment"
android:layout_width="@dimen/navigation_drawer_width"
android:layout_height="match_parent" android:layout_gravity="start"
app:layout="@layout/fragment_navigation_drawer" />
</android.support.v4.widget.DrawerLayout>
</RelativeLayout>
由于我的其他应用程序（来自模板的应用程序）运行良好，我认为问题不在于膨胀或与此相关的问题。
如果有人想要获取此模板，则基本版本中的here为{}。我没有添加引用，因为我已经更改了代码。但这来自here（西班牙语）。
Logcat将此返回给我：
07-23 13:52:10.962 21206-21206/com.example.jesus.myapplication E/RecyclerView? No adapter attached; skipping layout
07-23 13:52:11.006 21206-21206/com.example.jesus.myapplication D/AndroidRuntime? Shutting down VM
07-23 13:52:11.010 21206-21206/com.example.jesus.myapplication E/AndroidRuntime? FATAL EXCEPTION: main
Process: com.example.jesus.myapplication, PID: 21206
java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.support.v7.widget.RecyclerView$LayoutManager.canScrollVertically()' on a null object reference
at android.support.v7.widget.RecyclerView.computeVerticalScrollRange(RecyclerView.java:1535)
at android.view.View.onDrawScrollBars(View.java:12943)
at android.view.View.draw(View.java:15237)
at android.support.v7.widget.RecyclerView.draw(RecyclerView.java:2997)
at android.view.View.updateDisplayListIfDirty(View.java:14167)
at android.view.View.getDisplayList(View.java:14189)
at android.view.View.draw(View.java:14959)
at android.view.ViewGroup.drawChild(ViewGroup.java:3405)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3198)
at android.view.View.updateDisplayListIfDirty(View.java:14162)
at android.view.View.getDisplayList(View.java:14189)
at android.view.View.draw(View.java:14959)
at android.view.ViewGroup.drawChild(ViewGroup.java:3405)
at android.support.v4.widget.DrawerLayout.drawChild(DrawerLayout.java:1089)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3198)
at android.view.View.updateDisplayListIfDirty(View.java:14162)
at android.view.View.getDisplayList(View.java:14189)
at android.view.View.draw(View.java:14959)
at android.view.ViewGroup.drawChild(ViewGroup.java:3405)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3198)
at android.view.View.updateDisplayListIfDirty(View.java:14162)
at android.view.View.getDisplayList(View.java:14189)
at android.view.View.draw(View.java:14959)
at android.view.ViewGroup.drawChild(ViewGroup.java:3405)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3198)
at android.view.View.updateDisplayListIfDirty(View.java:14162)
at android.view.View.getDisplayList(View.java:14189)
at android.view.View.draw(View.java:14959)
at android.view.ViewGroup.drawChild(ViewGroup.java:3405)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3198)
at android.view.View.updateDisplayListIfDirty(View.java:14162)
at android.view.View.getDisplayList(View.java:14189)
at android.view.View.draw(View.java:14959)
at android.view.ViewGroup.drawChild(ViewGroup.java:3405)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3198)
at android.view.View.updateDisplayListIfDirty(View.java:14162)
at android.view.View.getDisplayList(View.java:14189)
at android.view.View.draw(View.java:14959)
at android.view.ViewGroup.drawChild(ViewGroup.java:3405)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3198)
at android.view.View.updateDisplayListIfDirty(View.java:14162)
at android.view.View.getDisplayList(View.java:14189)
at android.view.View.draw(View.java:14959)
at android.view.ViewGroup.drawChild(ViewGroup.java:3405)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3198)
at android.view.View.draw(View.java:15234)
at android.widget.FrameLayout.draw(FrameLayout.java:598)
at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:2650)
at android.view.View.updateDisplayListIfDirty(View.java:14167)
at android.view.View.getDisplayList(View.java:14189)
at android.view.ThreadedRenderer.updateViewTreeDisplayList(ThreadedRenderer.java:273)
at android.view.ThreadedRenderer.updateRootDisplayList(ThreadedRenderer.java:279)
at android.view.ThreadedRenderer.draw(ThreadedRenderer.java:318)
at android.view.ViewRootImpl.draw(ViewRootImpl.java:2530)
at android.view.ViewRootImpl.performDraw(ViewRootImpl.java:2352)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1982)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1061)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5885)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
at android.view.Choreographer.doCallbacks(Choreographer.java:580)
at android.view.Choreographer.doFrame(Choreographer.java:550)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
at android.os.Handler.handleCallback(Handler
然后，我们可以看到RecyclerView像我假设的那样有罪。它解释了我，RecyclerView指向一个空指针，然后得到一个空指针异常但是，真诚地，我不知道如何解决它。
你能帮我试一下我的错误吗？它编译好了，当我尝试在我的设备中运行它时它会在开放时返回给我一个FC。
答案 0 :(得分：1)
我刚刚意识到这是错的。它没有任何与回收者视图或布局有关的东西。我只是没有初始化变量： LinearLayoutManager和我的适配器（AnimeAdapter）。
只需添加recicle（）;到oncreate方法工作