Question

尝试在具有Firebase Realtime数据库的Recyclerview中添加searchView，但尽管CompatBar中显示图标，但我应用searchView时数据库活动崩溃

Main3Activity.java

 private RecyclerView mPeopleRV;
private DatabaseReference mDatabase;
private FirebaseRecyclerAdapter<News, NewsViewHolder> mPeopleRVAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_news);

}

private void firebaseSearch(String searchText) {
    Query firebaseSearchQuery = mDatabase.orderByChild("title").startAt(searchText).endAt(searchText + "\uf8ff");

    setTitle("News");
    MyDatabaseUtil.getDatabase();
    //"News" here will reflect what you have called your database in Firebase.
    mDatabase = FirebaseDatabase.getInstance().getReference().child("S");
    mDatabase.keepSynced(true);

    mPeopleRV = (RecyclerView) findViewById(R.id.myRecycleView);
    // FirebaseDatabase.getInstance().setPersistenceEnabled(true);
    DatabaseReference personsRef = FirebaseDatabase.getInstance().getReference().child("S");
    Query personsQuery = personsRef.orderByKey();

    mPeopleRV.hasFixedSize();
    mPeopleRV.setLayoutManager(new LinearLayoutManager(this));

    FirebaseRecyclerOptions personsOptions = new FirebaseRecyclerOptions.Builder<News>().setQuery(personsQuery, News.class).build();

    mPeopleRVAdapter = new FirebaseRecyclerAdapter<News, NewsViewHolder>(personsOptions) {
        @Override
        protected void onBindViewHolder(Main3Activity.NewsViewHolder holder, final int position, final News model) {
            holder.setTitle(model.getTitle());
            holder.setMandi(model.getMandi());
            holder.setMarket(model.getMarket());
            holder.setUrdu(model.getUrdu());
            holder.setBachat(model.getBachat());
            holder.setDesc(model.getDesc());
            holder.setImage(getBaseContext(), model.getImage());

            holder.mView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    final String url = model.getUrl();
                    Intent intent = new Intent(getApplicationContext(), NewsWebView.class);
                    intent.putExtra("id", url);
                    startActivity(intent);
                }
            });
        }

        @Override
        public Main3Activity.NewsViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

            View view = LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.news_row, parent, false);

            return new Main3Activity.NewsViewHolder(view);
        }
    };

    mPeopleRV.setAdapter(mPeopleRVAdapter);
}

@Override
public void onStart() {
    super.onStart();
     mPeopleRVAdapter.startListening();

}

@Override
public void onStop() {
    super.onStop();
    mPeopleRVAdapter.stopListening();


}

public class NewsViewHolder extends RecyclerView.ViewHolder {
    View mView;

    public NewsViewHolder(View itemView) {
        super(itemView);
        mView = itemView;
    }

    public void setTitle(String title) {
        TextView post_title = (TextView) mView.findViewById(R.id.post_title);
        post_title.setText(title);
    }

    public void setUrdu(String urdu) {
        TextView post_urdu = (TextView) mView.findViewById(R.id.Urdu);
        post_urdu.setText(urdu);
    }

    public void setMarket(String market) {
        TextView post_market = (TextView) mView.findViewById(R.id.market);
        post_market.setText(market);
    }

    public void setMandi(String mandi) {
        TextView post_mandi = (TextView) mView.findViewById(R.id.mundi);
        post_mandi.setText(mandi);
    }

    public void setBachat(String bachat) {
        TextView post_bachat = (TextView) mView.findViewById(R.id.bachat);
        post_bachat.setText(bachat);
    }


    public void setDesc(String desc) {
        TextView post_desc = (TextView) mView.findViewById(R.id.post_desc);
        post_desc.setText(desc);
    }

    public void setImage(Context ctx, String image) {
        ImageView post_image = (ImageView) mView.findViewById(R.id.post_image);
        Picasso.with(ctx).load(image).into(post_image);
    }
}
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main, menu);
        MenuItem item = menu.findItem(R.id.search);
        SearchView searchView = (SearchView) MenuItemCompat.getActionView(item);
        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                firebaseSearch(query);
                return false;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                return false;
            }
        });

        return super.onCreateOptionsMenu(menu);
    }



    @Override
    public void onBackPressed() {

        super.onBackPressed();
    }
}

Menu.xml

> <menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context=".Main3Activity">
    <item
        android:id="@+id/search"
        android:icon="@drawable/ic_home" android:title="search"
        app:showAsAction="always"
        app:actionViewClass="android.support.v7.widget.SearchView" />
</Menu>

Logcat错误 java.lang.RuntimeException：无法启动活动ComponentInfo {e.sszj_capricorn.requirementdatarecyclerviewtextview / e.sszz_capricorn.requirementdatarecyclerviewtextview.Main3Activity}：java.lang.NullPointerException：尝试调用虚拟方法'void void com.firebase.Re.Adapter。在空对象引用上的startListening（）' 在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2726）在android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:2787）在android.app.ActivityThread.-wrap12（ActivityThread.java）在android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1504）在android.os.Handler.dispatchMessage（Handler.java:102）在android.os.Looper.loop（Looper.java:154）在android.app.ActivityThread.main（ActivityThread.java:6247）在java.lang.reflect.Method.invoke（本机方法）在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:872）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:762）原因：java.lang.NullPointerException：尝试在空对象引用上调用虚拟方法'void com.firebase.ui.database.FirebaseRecyclerAdapter.startListening（）' 在e.sszj_capricorn.requirementdatarecyclerviewtextview.Main3Activity.onStart（Main3Activity.java:96）在android.app.Instrumentation.callActivityOnStart（Instrumentation.java:1249）在android.app.Activity.performStart（Activity.java:6774）在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2689）在android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:2787）在android.app.ActivityThread.-wrap12（ActivityThread.java）在android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1504）在android.os.Handler.dispatchMessage（Handler.java:102）在android.os.Looper.loop（Looper.java:154）在android.app.ActivityThread.main（ActivityThread.java:6247）在java.lang.reflect.Method.invoke（本机方法）在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:872）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:762）应用已终止。

空对象引用上的com.firebase.ui.database.FirebaseRecyclerAdapter.startListening（）'

0 个答案: