单击一项后，具有相同设计的 RecyclerView 的 Onclicklistener

Question

在这个问题之后我需要使用Adaptor：Implementing an RecycleView or CardView items with the same design for eachother

但是，这个实现有问题。这是我的MainActivity：

public class MainActivity extends AppCompatActivity {

    String TITLES[] = {"Home", "My Account", "Help", "About"};
    int ICONS[] = {R.drawable.ic_home, R.drawable.acc, R.drawable.ic_help, R.drawable.ic_about};
    String NAME = "Hi user!";
    int PROFILE = R.drawable.ic_account;
    RecyclerView mRecyclerView;
    RecyclerView.Adapter mAdapter;
    RecyclerView.LayoutManager mLayoutManager;
    //items
    RecyclerView recycle2;
    RecyclerView.Adapter adapter;
    RecyclerView.LayoutManager rec2lay;
    DrawerLayout Drawer;
    ActionBarDrawerToggle mDrawerToggle;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //FOR each item
        recycle2 = (RecyclerView)findViewById(R.id.rv);
        recycle2.setHasFixedSize(true);
        mRecyclerView = new RecyclerView(this);
        recycle2.setLayoutManager(rec2lay);
        adapter = new CardAdapter();
        recycle2.setAdapter(adapter);
                                            //try debuging
                //Codes for MainRecycle view
        mRecyclerView = (RecyclerView)findViewById(R.id.recycler_view);
        mRecyclerView.setHasFixedSize(true);
        mLayoutManager = new LinearLayoutManager(this);
        mRecyclerView.setLayoutManager(mLayoutManager);
        mAdapter = new CardAdapter();
        mRecyclerView.setAdapter(mAdapter);

        Toolbar toolbar = (Toolbar) findViewById(R.id.tool_bar);
        setSupportActionBar(toolbar);
        toolbar.setPadding(0, getStatusBarHeight(), 0, 0);

        mRecyclerView = (RecyclerView) findViewById(R.id.RecyclerView);
        mRecyclerView.setHasFixedSize(true);
        mAdapter = new MyAdapter(TITLES,ICONS,NAME,PROFILE,this);
        mRecyclerView.setAdapter(mAdapter);
        mLayoutManager = new LinearLayoutManager(this);
        mRecyclerView.setLayoutManager(mLayoutManager);
        Drawer = (DrawerLayout) findViewById(R.id.DrawerLayout);
        mDrawerToggle = new ActionBarDrawerToggle(this,Drawer, toolbar, R.string.openDrawer, R.string.closeDrawer){
            @Override
            public void onDrawerOpened(View drawerView) {
                super.onDrawerOpened(drawerView);
            }
            @Override
            public void onDrawerClosed(View drawerView) {
                super.onDrawerClosed(drawerView);
            }
        };
        Drawer.setDrawerListener(mDrawerToggle);
        mDrawerToggle.syncState();
    }
    public int getStatusBarHeight() {
        int result = 0;
        int resourceId = getResources().getIdentifier("status_bar_height", "dimen", "android");
        if (resourceId > 0) {
            result = getResources().getDimensionPixelSize(resourceId);
        }
        return result;
    }
}

我正在使用这个适配器在 ma​​inLayout 中显示 Recycleview：

public class CardAdapter extends RecyclerView.Adapter<CardAdapter.ViewHolder> {

    List<NatureItem> mItems;

    public CardAdapter() {
        super();
        mItems = new ArrayList<NatureItem>();
        NatureItem nature = new NatureItem();
        nature.setName("The Great Barrier Reef");
        nature.setDes("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt" +
                      "ut labore et dolore magna aliqua. Ut enim ad minim veniam.");
        nature.setThumbnail(R.drawable.great_barrier_reef);
        mItems.add(nature);

        nature = new NatureItem();
        nature.setName("Grand Canyon");
        nature.setDes("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt" +
                "ut labore et dolore magna aliqua.");
        nature.setThumbnail(R.drawable.grand_canyon);
        mItems.add(nature);

        nature = new NatureItem();
        nature.setName("Baltoro Glacier");
        nature.setDes("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt" +
                "ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis.");
        nature.setThumbnail(R.drawable.baltoro_glacier);
        mItems.add(nature);

        nature = new NatureItem();
        nature.setName("Iguazu Falls");
        nature.setDes("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt" +
                "ut labore et dolore magna aliqua. Ut enim ad minim veniam.");
        nature.setThumbnail(R.drawable.ig);
        mItems.add(nature);


        nature = new NatureItem();
        nature.setName("Aurora Borealis");
        nature.setDes("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt" +
                      "ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud.");
        nature.setThumbnail(R.drawable.aurora_borealis);
        mItems.add(nature);
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        View v = LayoutInflater.from(viewGroup.getContext())
                .inflate(R.layout.recycler_view_card_item, viewGroup, false);
        ViewHolder viewHolder = new ViewHolder(v);
        return viewHolder;
    }

    @Override
    public void onBindViewHolder(ViewHolder viewHolder, int i) {
        NatureItem nature = mItems.get(i);
        viewHolder.tvNature.setText(nature.getName());
        viewHolder.tvDesNature.setText(nature.getDes());
        viewHolder.imgThumbnail.setImageResource(nature.getThumbnail());
    }

    @Override
    public int getItemCount() {
        return mItems.size();
    }

    class ViewHolder extends RecyclerView.ViewHolder{

        public ImageView imgThumbnail;
        public TextView tvNature;
        public TextView tvDesNature;

        public ViewHolder(View itemView) {
            super(itemView);
            imgThumbnail = (ImageView)itemView.findViewById(R.id.img_thumbnail);
            tvNature = (TextView)itemView.findViewById(R.id.tv_nature);
            tvDesNature = (TextView)itemView.findViewById(R.id.tv_des_nature);
        }
    }
}

来自这个很好的教程：http://www.exoguru.com/android/ui/cardview/custom-android-list.html

这是我的适配器，当用户单击上述项目中的一个项目时（实际上是 5 个项目） item（五项），但是，在这个活动中使用不同的图片和不同的名称：

ItemsAdaptor：

public class ItemsAdaptor extends RecyclerView.Adapter<ItemsAdaptor.PersonViewHolder> {

    @Override
    public PersonViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.activity_main, viewGroup, false);
        PersonViewHolder pvh = new PersonViewHolder(v);
        return pvh;
    }



    @Override
    public void onBindViewHolder(PersonViewHolder personViewHolder, int i) {
        personViewHolder.personName.setText(persons.get(i).name);
        personViewHolder.personAge.setText(persons.get(i).age);
        personViewHolder.personPhoto.setImageResource(persons.get(i).photoId);
    }
    @Override
    public void onAttachedToRecyclerView(RecyclerView recyclerView) {
        super.onAttachedToRecyclerView(recyclerView);
    }

    @Override
    public int getItemCount() {
        return persons.size();
    }
    List<Person> persons;

    ItemsAdaptor(List<Person> persons){
        this.persons = persons;
    }

    public static class PersonViewHolder extends RecyclerView.ViewHolder {
        CardView cv;
        TextView personName;
        TextView personAge;
        ImageView personPhoto;

        PersonViewHolder(View itemView) {
            super(itemView);
            cv = (CardView)itemView.findViewById(R.id.cv);
            personName = (TextView)itemView.findViewById(R.id.person_name);
            personAge = (TextView)itemView.findViewById(R.id.person_age);
            personPhoto = (ImageView)itemView.findViewById(R.id.person_photo);
        }
    }

}

那么，我们如何才能实现这一目标以及我们需要做什么？

这是执行此操作后的日志错误：

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.test.test/com.test.test.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.widget.RecyclerView.setHasFixedSize(boolean)' on a null object reference
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2325)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
            at android.app.ActivityThread.access$800(ActivityThread.java:151)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5254)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.widget.RecyclerView.setHasFixedSize(boolean)' on a null object reference
            at com.test.test.MainActivity.onCreate(MainActivity.java:41)
            at android.app.Activity.performCreate(Activity.java:5990)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
            at android.app.ActivityThread.access$800(ActivityThread.java:151)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5254)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

看来，android.support.v7.widget.RecyclerView.setHasFixedSize(boolean)有错误

有什么问题？

编辑： MainActivty 布局：

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/DrawerLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:elevation="7dp">

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <include
        android:id="@+id/tool_bar"
        layout="@layout/tool_bar">
    </include>
    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
</LinearLayout>
<android.support.v7.widget.RecyclerView
    android:id="@+id/RecyclerView"
    android:layout_width="290dp"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    android:background="#ffffff"
    android:scrollbars="vertical">
</android.support.v7.widget.RecyclerView>

还有，items_recycleview：

<?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"
    android:padding="16dp"
    android:orientation="vertical">
    <android.support.v7.widget.CardView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/cv"
        >
        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:padding="16dp"
            >
            <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/person_photo"
                android:src="@mipmap/ic_launcher"
                android:layout_alignParentLeft="true"
                android:layout_alignParentTop="true"
                android:layout_marginRight="16dp"
                />
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/person_name"
                android:layout_toRightOf="@+id/person_photo"
                android:layout_alignParentTop="true"
                android:textSize="30sp"
                />
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/person_age"
                android:layout_toRightOf="@+id/person_photo"
                android:layout_below="@+id/person_name"
                />
        </RelativeLayout>
    </android.support.v7.widget.CardView>
    <android.support.v7.widget.RecyclerView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/rv"/>
</LinearLayout>

如何解决这个问题？

类似于 whatsapp 联系人或 Telegram 联系人，当您单击一项联系人时，它向我们展示了相同的设计，但数字或图片不同。在设计上，没有任何变化。

谢谢

Answer 1

由于您的布局文件中有 3 个 RecyclerView，因此您需要创建 3 个 RecyclerView 变量。现在，您将两个 RecyclerView 分配给名为 mRecylcerView 的同一个变量。创建一个新的 RecyclerView 变量，您将在其中创建其他变量并使用它。例如：

RecyclerView recycle3;
RecyclerView.Adapter adapter2;
RecyclerView.LayoutManager rec3lay;