我在 xml 中使用 arraylist 并循环但导航抽屉不显示

Question

我该如何解决？

导航Drawer.java

public class NavigationDrawerFragment extends Fragment {
public static final String PRE_FILE_NAME = "testpre";
public static final String KEY_USER_LEARNED_DRAWER = "user_learned_drawer";
private RecyclerView recyclerView;
private ActionBarDrawerToggle mDrawerToggle;
private DrawerLayout mDrawerLayout;
private MyAdapter adapter;
private boolean mUserLearnedDrawer;
private boolean mFromSavedInstanceState;
private View containerView;

public NavigationDrawerFragment() {
    // Required empty public constructor
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mUserLearnedDrawer = Boolean.valueOf(readFromPreferences(getActivity(), KEY_USER_LEARNED_DRAWER, "false"));
    if (savedInstanceState != null) {
        mFromSavedInstanceState = true;
    }
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View layout = inflater.inflate(R.layout.fragment_navigation_drawer, container, false);
    recyclerView = (RecyclerView) layout.findViewById(R.id.drawerList);
    adapter = new MyAdapter(getActivity(), getData());
    recyclerView.setAdapter(adapter);
    recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
    return layout;
}

public List<Information> getData() {
    List<Information> data = new ArrayList<>();
    String[] titles = getResources().getStringArray(R.array.drawer_item_array);
    for (int i = 0; i < titles.length; i++) {
        Information current = new Information();
        current.title = titles[i];
        data.add(current);
    }
    return data;
}

public void setUp(int fragmentId, DrawerLayout drawerLayout, final Toolbar toolbar) {
    containerView = getActivity().findViewById(fragmentId);
    mDrawerLayout = drawerLayout;
    mDrawerToggle = new ActionBarDrawerToggle(getActivity(), drawerLayout, toolbar, R.string.drawer_open, R.string.drawer_close) {
        @Override
        public void onDrawerOpened(View drawerView) {
            super.onDrawerOpened(drawerView);
            if (!mUserLearnedDrawer) {
                mUserLearnedDrawer = true;
                saveToPreferences(getActivity(), KEY_USER_LEARNED_DRAWER, mUserLearnedDrawer + "");
            }
            getActivity().invalidateOptionsMenu();
        }

        @Override
        public void onDrawerClosed(View drawerView) {
            super.onDrawerClosed(drawerView);
            getActivity().invalidateOptionsMenu();
        }
    };
    if (!mUserLearnedDrawer && !mFromSavedInstanceState) {
        mDrawerLayout.openDrawer(containerView);
    }
    mDrawerLayout.setDrawerListener(mDrawerToggle);
    mDrawerLayout.post(new Runnable() {
        @Override
        public void run() {
            mDrawerToggle.syncState();
        }
    });
}

public static void saveToPreferences(Context context, String preferenceName, String preferenceValue) {
    SharedPreferences sharedPreferences = context.getSharedPreferences(PRE_FILE_NAME, Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = sharedPreferences.edit();
    editor.putString(preferenceName, preferenceValue);
    editor.apply();
}

    public static String readFromPreferences(Context context, String preferenceName, String defaultValue) {
        SharedPreferences sharedPreferences = context.getSharedPreferences(PRE_FILE_NAME, Context.MODE_PRIVATE);
        return sharedPreferences.getString(preferenceName, defaultValue);
    }
}

Information.java

public class Information {
   String title;
}

MyAdapter.java

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import java.util.Collections;
import java.util.List;

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder>            {

private LayoutInflater inflater;
List<Information> data = Collections.emptyList();

public MyAdapter(Context context, List<Information> data){
    inflater = LayoutInflater.from(context);
    this.data = data;
}

@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = inflater.inflate(R.layout.custom_row, parent, false);
    MyViewHolder holder = new MyViewHolder(view);
    return holder;
}

@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
    Information current = data.get(position);
    holder.title.setText(current.title);
}

@Override
public int getItemCount() {
    return 0;
}

class MyViewHolder extends RecyclerView.ViewHolder{
    TextView title;
    public MyViewHolder(View itemView) {
        super(itemView);
        title = (TextView) itemView.findViewById(R.id.listItem);
     }
    }
  }

custom_row.xml 在 layout.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">

<TextView
    android:id="@+id/listItem"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_vertical"
    android:textColor="@color/textPrimaryColor"/>
</LinearLayout>

naviagataion_drawer.xml 布局

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#FFF"    
    <android.support.v7.widget.RecyclerView
        android:id="@+id/drawerList"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
    </android.support.v7.widget.RecyclerView>
</RelativeLayout>

string.xml

<resource>
  <string name="action_settings">Settings</string>
    <string name="drawer_open" translatable="false">Open</string>
    <string name="drawer_close" translatable="false">Close</string>
    <array name="drawer_item_array">
     <item>Read</item>
     <item>Create</item>
     <item>Edit</item>
     <item>Questionnaire</item>
     <item>Settings</item>
   </array>
 </resource>

我确实关注[url]https://www.youtube.com/watch?v=OoCySqneJno&index=14&list=PLonJJ3BVjZW6CtAMbJz1XD8ELUs1KXaTD[/url] 他在 NavigationDrawer.java 中使用数组，但我在 string.xml

中使用数组

感谢您的帮助。

Answer 1

在您的 class MyAdapter 中，您写道：

@Override
public int getItemCount() {
    return 0;
}

这应该是

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

我在 xml 中使用 arraylist 并循环但导航抽屉不显示

I'm using arraylist in xml and cycling but navigation drawer doesn't show

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