java - 如何使用搜索 View 而不一直显示回收器 View ？

Question

我有一个 Activity ，其中有一些与此无关的按钮，以及顶部的相对布局内的搜索 View 。我想要的是，当我在 searchview 上写字时，recyclerview 数组出现在屏幕上，但是当我没有写任何内容时，只会出现我之前告诉过你的按钮。

为了避免在不使用 searchview 时显示 recyclerView，我所做的就是在其宽度和高度参数中设置 0dp。

这是我的 MainActivity.java:

public class Dishes extends AppCompatActivity implements Adaptador2.OnRecipeListener {
    Button boton_verdura;
    Button boton_carne;
    Button boton_pasta;
    Button boton_sopas;
    Button boton_pescados;
    Button boton_ensaladas;
    private RecyclerView recyclerView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_dishes);
        this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

        boton_verdura=(Button) findViewById(R.id.boton_verduras);
        boton_carne=(Button) findViewById(R.id.boton_carnes);
        boton_pasta=(Button) findViewById(R.id.boton_pasta);
        boton_sopas=(Button) findViewById(R.id.boton_sopas);
        boton_pescados=(Button) findViewById(R.id.boton_pescados);
        boton_ensaladas=(Button) findViewById(R.id.boton_ensaladas);

        boton_verdura.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent in = new Intent(Dishes.this,Verduras.class);
                startActivity(in);
            }
        });

        boton_carne.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent in = new Intent(Dishes.this,Carnes.class);
                startActivity(in);
            }
        });

        boton_pasta.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent in = new Intent(Dishes.this,Pasta.class);
                startActivity(in);
            }
        });

        boton_sopas.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent in = new Intent(Dishes.this,Sopas.class);
                startActivity(in);
            }
        });

        boton_pescados.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent in = new Intent(Dishes.this,Pescados.class);
                startActivity(in);
            }
        });

        boton_ensaladas.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent in = new Intent(Dishes.this,Ensaladas.class);
                startActivity(in);
            }
        });


        recyclerView = findViewById(R.id.lv_prueba);
        LinearLayoutManager layoutManager = new LinearLayoutManager(this);
        layoutManager.setOrientation(LinearLayoutManager.VERTICAL);

        recyclerView.setLayoutManager(layoutManager);

        List<Entidad2> listItems = new ArrayList<>();
        listItems.add(new Entidad2(R.drawable.calabacines_3, "Calabacines", " 10 min.", 4, R.drawable.color_ensaladas));
        listItems.add(new Entidad2(R.drawable.patatas_deluxe_especiadas_70523_300_150, "Patatas", " 15 min.", 2, R.drawable.color_ensaladas));
        listItems.add(new Entidad2(R.drawable.tomate, "Tomates", " 2 min.", 5, R.drawable.color_ensaladas));

        Adaptador2 Adaptador2 = new Adaptador2(listItems, this);
        recyclerView.setAdapter(Adaptador2);
        Adaptador2.notifyDataSetChanged();
    }

    @Override
    public void OnRecipe(int position) {

        if(position == 0){
            Intent in = new Intent(this, Judias_verdes.class);
            startActivity(in);
        }
        if(position == 1){
            Intent in = new Intent(this, Sardinas_fritas.class);
            startActivity(in);
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.example_menu, menu);

        MenuItem searchItem = menu.findItem(R.id.action_search);
        SearchView searchView = (SearchView) searchItem.getActionView();

        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                return false;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                Adaptador2.getFilter().filter(newText);
                return false;
            }
        });
        return true;
    }
}

这是我的 Mainactivity.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#ffff00"
    tools:context=".Dishes">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="84dp">

            <android.support.v7.widget.SearchView
                android:id="@+id/rv_buscar"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginLeft="35dp"
                android:layout_marginRight="35dp"
                android:background="@drawable/line"
                android:layout_centerVertical="true"
                android:gravity="center_vertical">

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

        </RelativeLayout>

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <Button
                android:id="@+id/boton_sopas"
                android:layout_width="match_parent"
                android:layout_height="80dp"
                android:layout_marginLeft="35dp"
                android:layout_marginRight="35dp"
                android:layout_weight="1"
                android:background="@drawable/boton_redondo"
                android:drawableLeft="@drawable/logo_sopa_15"
                android:drawableStart="@drawable/logo_sopa_15"
                android:text="   Sopas"
                android:textAllCaps="false"
                android:textSize="40sp"
                android:textStyle="normal"
                android:textAlignment="textStart"
                android:layout_gravity="start"
                app:fontFamily="@font/san_francisco_display_regular"
                tools:ignore="HardcodedText,MissingConstraints"/>

            <Button
                android:id="@+id/boton_pescados"
                android:layout_width="match_parent"
                android:layout_height="80dp"
                android:layout_marginLeft="35dp"
                android:layout_marginRight="35dp"
                android:layout_weight="1"
                android:layout_marginTop="24dp"
                android:background="@drawable/boton_redondo"
                android:drawableLeft="@drawable/logo_pescado3_30_15"
                android:drawableStart="@drawable/logo_pescado3_30_15"
                android:text="   Pescados"
                android:textAllCaps="false"
                android:textSize="40sp"
                android:textStyle="normal"
                android:textAlignment="textStart"
                android:layout_gravity="start"
                app:fontFamily="@font/san_francisco_display_regular"
                tools:ignore="HardcodedText,MissingConstraints" />

            <Button
                android:id="@+id/boton_ensaladas"
                android:layout_width="match_parent"
                android:layout_height="80dp"
                android:layout_marginLeft="35dp"
                android:layout_marginRight="35dp"
                android:layout_weight="1"
                android:layout_marginTop="24dp"
                android:background="@drawable/boton_redondo"
                android:drawableLeft="@drawable/logo_ensalada3_30_15"
                android:drawableStart="@drawable/logo_ensalada3_30_15"
                android:text="   Ensaladas"
                android:textAllCaps="false"
                android:textSize="40sp"
                android:textStyle="normal"
                android:textAlignment="textStart"
                android:layout_gravity="start"
                app:fontFamily="@font/san_francisco_display_regular"
                tools:ignore="HardcodedText,MissingConstraints" />

            <Button
                android:id="@+id/boton_carnes"
                android:layout_width="match_parent"
                android:layout_height="80dp"
                android:layout_marginLeft="35dp"
                android:layout_marginRight="35dp"
                android:layout_weight="1"
                android:layout_marginTop="24dp"
                android:background="@drawable/boton_redondo"
                android:drawableLeft="@drawable/logo_filete_30_15"
                android:drawableStart="@drawable/logo_filete_30_15"
                android:text="   Carnes"
                android:textAllCaps="false"
                android:textSize="40sp"
                android:textStyle="normal"
                android:textAlignment="textStart"
                android:layout_gravity="start"
                app:fontFamily="@font/san_francisco_display_regular"
                tools:ignore="DuplicateIds,HardcodedText,MissingConstraints" />

            <Button
                android:id="@+id/boton_verduras"
                android:layout_width="match_parent"
                android:layout_height="80dp"
                android:layout_marginLeft="35dp"
                android:layout_marginRight="35dp"
                android:layout_weight="1"
                android:layout_marginTop="24dp"
                android:background="@drawable/boton_redondo"
                android:drawableLeft="@drawable/logo_vegetables_30_15"
                android:drawableStart="@drawable/logo_vegetables_30_15"
                android:text="   Verduras"
                android:textAllCaps="false"
                android:textSize="40sp"
                android:textStyle="normal"
                android:textAlignment="textStart"
                android:layout_gravity="start"
                app:fontFamily="@font/san_francisco_display_regular"
                tools:ignore="HardcodedText,MissingConstraints" />

            <Button
                android:id="@+id/boton_pasta"
                android:layout_width="match_parent"
                android:layout_height="80dp"
                android:layout_marginBottom="15dp"
                android:layout_marginLeft="35dp"
                android:layout_marginRight="35dp"
                android:layout_weight="1"
                android:layout_marginTop="24dp"
                android:background="@drawable/boton_redondo"
                android:drawableLeft="@drawable/logo_pizza_30_15"
                android:drawableStart="@drawable/logo_pizza_30_15"
                android:text="   Pasta"
                android:textAllCaps="false"
                android:textSize="40sp"
                android:textStyle="normal"
                android:textAlignment="textStart"
                android:layout_gravity="start"
                android:fontFamily="@font/san_francisco_display_regular"
                tools:ignore="HardcodedText,MissingConstraints" />

        </LinearLayout>
    </ScrollView>

        <android.support.v7.widget.RecyclerView
            android:id="@+id/lv_prueba"
            android:layout_width="0dp"
            android:layout_height="0dp">
        </android.support.v7.widget.RecyclerView>

    </LinearLayout>
</RelativeLayout>

这就是Adapter.java:

ackage com.test.platos_4;

import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Filter;
import android.widget.Filterable;
import android.widget.ImageView;
import android.widget.RatingBar;
import android.widget.TextView;

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

public class Adaptador2  extends RecyclerView.Adapter<Adaptador2.ViewHolder> implements Filterable
{
    private List<Entidad2> listItems;
    private List<Entidad2> listItemsFull;
    private OnRecipeListener mOnRecipeListener;

    public  Adaptador2(List<Entidad2> listItems, OnRecipeListener onRecipeListener) {
        this.listItems = listItems;
        listItemsFull = new ArrayList<>(listItems);
        this.mOnRecipeListener = onRecipeListener;
    }


    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.elemento_lista2, parent, false);
        return new ViewHolder(view, mOnRecipeListener);
    }

    @Override
    public void onBindViewHolder(ViewHolder viewholder, int position) {
        int resource = listItems.get(position).getImgFoto();
        String title = listItems.get(position).getTitulo();
        String time = listItems.get(position).getTiempo();
        int barra = listItems.get(position).getRating();
        final int priority = listItems.get(position).getPriority();
        //int fondo = listItems.get(position).getColorfondo();
        viewholder.setData(resource, title, time, barra);

        //You can pass the clicked item's priority back to your activity like this
        viewholder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mOnRecipeListener.OnRecipe(priority);
            }
        });
        // por si necesito color de fondo viewholder.setData(resource, title, time, barra, fondo);
    }

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

    @Override
    public Filter getFilter() {
        return exampleFilter;
    }

    private Filter exampleFilter = new Filter() {
        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            List<Entidad2> filteredList = new ArrayList<>();

            if (constraint == null || constraint.length() == 0) {
                filteredList.addAll(listItemsFull);
            }
            else {
                String filterPattern = constraint.toString().toLowerCase().trim();

                for (Entidad2 item : listItemsFull) {
                    if (item.getTitulo().toLowerCase().contains(filterPattern)) {
                        filteredList.add(item);
                    }
                }
            }

            FilterResults results = new FilterResults();
            results.values = filteredList;

            return results;
        }

        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) {
            listItems.clear();
            listItems.addAll((List)results.values);
            notifyDataSetChanged();
        }
    };

    class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

        private ImageView imgFoto;
        private TextView titulo;
        private TextView tiempo;
        private RatingBar ratingBar;
        //private ImageView colorfondo;
        OnRecipeListener onRecipeListener;

        public ViewHolder(View itemView, OnRecipeListener onRecipeListener) {
            super(itemView);

            imgFoto = itemView.findViewById(R.id.imgFoto);
            titulo = itemView.findViewById(R.id.tvTitulo);
            tiempo = itemView.findViewById(R.id.tvTiempo);
            ratingBar = itemView.findViewById(R.id.ratingBarVerd);
            //colorfondo = itemView.findViewById(R.id.colorfondo);
            // this.onRecipeListener = onRecipeListener;

        }

        //por si necesito color de fondo private void setData(int resource, String title, String time, int barra, int fondo){
        private void setData(int resource, String title, String time, int barra){
            imgFoto.setImageResource(resource);
            titulo.setText(title);
            tiempo.setText(time);
            ratingBar.setRating(barra);
            //colorfondo.setImageResource(fondo);

        }

        @Override
        public void onClick(View v) {
        }
    }

    public interface OnRecipeListener{
        void OnRecipe(int priority);
    }
}

但是出现错误:

请帮助我不知道该怎么做，因为我从未使用过 SearchView，所以任何帮助都会有用。

谢谢

当我尝试在运行应用程序时进入 Activity 时出现的新问题:

08-14 16:33:07.115 17470-17470/com.test.platos_4 E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.test.platos_4, PID: 17470
    java.lang.ClassCastException: android.support.v7.widget.SearchView cannot be cast to android.widget.SearchView
        at com.test.platos_4.Dishes.onCreateOptionsMenu(Dishes.java:136)
        at android.app.Activity.onCreatePanelMenu(Activity.java:3546)
        at android.support.v4.app.FragmentActivity.onCreatePanelMenu(FragmentActivity.java:328)
        at android.support.v7.view.WindowCallbackWrapper.onCreatePanelMenu(WindowCallbackWrapper.java:93)
        at android.support.v7.app.AppCompatDelegateImplBase$AppCompatWindowCallbackBase.onCreatePanelMenu(AppCompatDelegateImplBase.java:332)
        at android.support.v7.app.AppCompatDelegateImplV9.preparePanel(AppCompatDelegateImplV9.java:1370)
        at android.support.v7.app.AppCompatDelegateImplV9.doInvalidatePanelMenu(AppCompatDelegateImplV9.java:1650)
        at android.support.v7.app.AppCompatDelegateImplV9$1.run(AppCompatDelegateImplV9.java:134)
        at android.os.Handler.handleCallback(Handler.java:873)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:201)
        at android.app.ActivityThread.main(ActivityThread.java:6815)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:873)
08-14 16:33:07.119 17470-17470/com.test.platos_4 E/MQSEventManagerDelegate: failed to get MQSService.

Answer 1

您看到的 getFilter() 错误是因为您尝试在 Adaptador2 上调用 getFilter()，但由于 getFilter() 不是不是静态方法，您需要在适配器实例上调用它，而不是像 someInstanceOfAdapterClass.getFilter()

这样的适配器类

一个主要问题是您将适配器类实例命名为与类相同的名称，这是一个非常糟糕的主意......在这里:

Adaptador2 Adaptador2 = new Adaptador2(listItems, this); // this is bad
recyclerView.setAdapter(Adaptador2);
Adaptador2.notifyDataSetChanged();

如果您想将变量重命名为与类名不同的名称，常见的做法是使用小写字母。您还需要在 Activity 变量中跟踪它，以便可以在 onCreateOptionsMenu 中访问它，因此请执行以下操作:

// at the top of your main activity define it
private Adaptador2 adaptador2;

// create your instance of it 
adaptador2 = new Adaptador2(listItems, this);
recyclerView.setAdapter(adaptador2);
adaptador2.notifyDataSetChanged();

// in onCreateOptionsMenu use lower case one to reference the object instance not 
// the class 
adaptador2.getFilter().filter(newText);

<小时/>

(我还没有测试过，但它可能有效)

至于隐藏回收器 View ，您可以在 onQueryChanged 方法中执行以下操作:

@Override
public boolean onQueryTextChange(String newText) {
    // this will hide your recycler anytime the search query is empty
    // and show it anytime there is a search query
    if (newText == "") {
        recyclerView.setVisibilty(View.GONE);
    } else {
        recyclerView.setVisibilty(View.VISIBLE);
    }

    adaptador2.getFilter().filter(newText);
    return false;
}