Question

我正在尝试使用RecyclerView创建导航抽屉。我正在关注YouTube上的教程，因为我是新手。问题是RecyclerView没有显示适配器的任何数据。我需要帮助。对此有任何建议表示赞赏。

NavigationDrawerFragment.java

package com.pixalstudio.cakedekho;

import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;

import java.util.ArrayList;
import java.util.List;


/**
 * A simple {@link Fragment} subclass.
 */
public class NavigationDrawerFragment extends Fragment {
    int i=0;
    private RecyclerView recyclerView;
    public static final String PREF_FILE_NAME = "testpref";
    public static final String KEY_USER_LEARNED_DRAWER = "user_learned_drawer";
    private ActionBarDrawerToggle mDrawerToggle;
    private DrawerLayout mDrawerLayout;
    private InfoAdapter 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) {
        // Inflate the layout for this fragment

        View layout = inflater.inflate(R.layout.fragment_navigation_drawer, container, false);
        recyclerView = (RecyclerView) layout.findViewById(R.id.drawerList);
        adapter = new InfoAdapter(getActivity(), getData());
        recyclerView.setAdapter(adapter);
        recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
        return layout;
    }

    public List<Information> getData() {

        List<Information> data = new ArrayList<>();
        int[] icons = {R.drawable.seven1, R.drawable.seven2, R.drawable.seven3, R.drawable.seven4};
        String[] titles = {"Login", "Location", "Home", "About Us"};
        for (int i=0; i < titles.length && i < icons.length; i++) ;
        {

            Information current = new Information();
            current.iconId = icons[i];
            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(PREF_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(PREF_FILE_NAME, Context.MODE_PRIVATE);
        return sharedPreferences.getString(preferenceName, defaultValue);
    }

}

Information.java

package com.pixalstudio.cakedekho;

/**
 * Created by akkie on 7/10/2015.
 */
public class Information {
    int iconId;
    String title;
}

InfoAdapter.java

package com.pixalstudio.cakedekho;

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.ImageView;
import android.widget.TextView;

import java.util.Collections;
import java.util.List;

/**
 * Created by akkie on 7/10/2015.
 */
public class InfoAdapter extends RecyclerView.Adapter<InfoAdapter.MyViewHolder> {

    List<Information> data = Collections.emptyList();
    private LayoutInflater inflater;
    public InfoAdapter(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.customrow, 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);
        holder.icon.setImageResource(current.iconId);

    }

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

    class MyViewHolder extends RecyclerView.ViewHolder {

        TextView title;
        ImageView icon;


        public MyViewHolder(View itemView) {
            super(itemView);
            title = (TextView) itemView.findViewById(R.id.listText);
            icon = (ImageView) itemView.findViewById(R.id.listIcon);
        }

    }
}

customrow.xml

<?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:orientation="horizontal"
    >

    <ImageView

        android:id="@+id/listIcon"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical"
        android:padding="8dp"
        android:src="@drawable/seven1" />

    <TextView
        android:id="@+id/listText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical"
        android:padding="8dp"
        android:text="Dummy Text" />

</LinearLayout>

fragment_navigation_drawer.xml

    <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="#DADADA"
        tools:context="com.pixalstudio.cakedekho.NavigationDrawerFragment">

        <LinearLayout

            android:id="@+id/containerDrawerImage"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="#FB8C00">

            <ImageView
                android:layout_width="240dp"
                android:layout_height="140dp"
                android:src="@drawable/ic_abstract1" />

        </LinearLayout>

        <android.support.v7.widget.RecyclerView

            android:layout_below="@+id/containerDrawerImage"
            android:id="@+id/drawerList"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">


        </android.support.v7.widget.RecyclerView>

    </RelativeLayout>

如果有人需要任何其他信息来解决我的问题，请告诉我。提前谢谢。

RecyclerView数据未显示

0 个答案: