Question

我正在关注slidenerd Material design tutorial（Android RecyclerView示例第1,2,3,4部分）＆amp;我正在使用真实设备来测试我的android应用程序。我已成功构建导航抽屉和放大器当我尝试通过添加适配器（ThalakazAdapter.java）将RecylerView添加到其中时，应用程序很快就会停止。

这是我的NavigationDrawerFragment.java

Regexp.union("?","!",".")

这是我的适配器（ThalakazAdapter.java）

/\?|!|\./

我的信息.java类

package com.thaalakaz.nadeesha.materialdesignapp1;


import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
//import android.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.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.support.v4.app.Fragment;

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

/**
 * A simple {@link Fragment} subclass.
 */
public class NavigationDrawerFragment extends Fragment {

    private RecyclerView recyclerView;
    public static final String PREF_FILE_NAME = "testpref";
    public static final String KAY_USER_LEARNED_DRAWER ="user_learned_drawer";

    private ActionBarDrawerToggle mDrawerToggle;
    private DrawerLayout mDrawerLayout;

    private  ThalakazAdapter 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(),KAY_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.drawer_layout);

        adapter = new ThalakazAdapter(getActivity(),getData());
        recyclerView.setAdapter(adapter);
        recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
        return layout;
    }

    public static List<Information> getData(){

        List<Information> data = new ArrayList<>();
        int[] icons ={R.drawable.ic_m,R.drawable.ic_m1,R.drawable.ic_m2,R.drawable.ic_m3};
        String[] titles = {"Nadeesha","Thilakarathne","Semini","Roshani"};

        for (int  i=0;i<titles.length && i<icons.length;i++){
            Information current = new Information();
            current.iconId = icons[i];
            current.titlel = 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(),KAY_USER_LEARNED_DRAWER,mUserLearnedDrawer+"");
               }
                getActivity().invalidateOptionsMenu();
            }

            @Override
            public void onDrawerClosed(View drawerView) {
                super.onDrawerClosed(drawerView);
                getActivity().invalidateOptionsMenu();
            }

            @Override
            public void onDrawerSlide(View drawerView, float slideOffset) {

                if (slideOffset<0.6){
                    toolbar.setAlpha(1-slideOffset);
                }

            }

        };

        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 prferenceName,String preferenceValue){
        SharedPreferences sharedPreferences = context.getSharedPreferences(PREF_FILE_NAME,Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.putString(prferenceName,preferenceValue);
        editor.apply();
    }

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

您可以从here

查看我的整个项目

logcat的

package com.thaalakaz.nadeesha.materialdesignapp1;

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.ListView;
import android.widget.TextView;

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

/**
 * Created by hp on 7/22/2015.
 */
public class ThalakazAdapter extends RecyclerView.Adapter <ThalakazAdapter.myViewHolder>{

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

    public ThalakazAdapter(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.titlel);
       holder.icon.setImageResource(current.iconId);
    }



    @Override
    public int getItemCount() {

        return 0;
    }

    class myViewHolder extends RecyclerView.ViewHolder{
        ImageView icon;
        TextView title;
        public myViewHolder(View itemView) {

            super(itemView);
            title = (TextView) itemView.findViewById(R.id.listText);
            icon = (ImageView) itemView.findViewById(R.id.listIcon);

        }
    }
}

fragment_navigation_drawer.xml

package com.thaalakaz.nadeesha.materialdesignapp1;

/**
 * Created by hp on 7/22/2015.
 */
public class Information {
    int iconId;
    String titlel;
}

Answer 1

你的onCreateView中的

你正在寻找错误的id。变化

recyclerView = (RecyclerView) layout.findViewById(R.id.drawer_layout);

与

recyclerView = (RecyclerView) layout.findViewById(R.id.drawerList);

我还注意到，在你的Adapter构造函数中，你正在向自己说明这个数据。变化

this.data = this.data;

到

this.data = data

且getItemCount不应该return 0，但是数据的大小（如果它不为空）

不幸的是，当尝试实施RecylerView时，app已在Android中停止

1 个答案: