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Android - Implementare un filtro di ricerca in una RecyclerView

Il nostro team di redattori ha cercato a lungo di rispondere alla tua domanda, ti lasciamo la risoluzione quindi speriamo che ti possa essere di grande aiuto.

Soluzione:

nell'adattatore aggiungere una nuova funzione per aggiornare l'elenco

public void updateList(List list){
     displayedList = list;
     notifyDataSetChanged();
}

aggiungere textWatcher per la ricerca, supponendo di utilizzare Edittext come campo di ricerca

searchField.addTextChangedListener(new TextWatcher() {
        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {

            // TODO Auto-generated method stub
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            // TODO Auto-generated method stub
        }

        @Override
        public void afterTextChanged(Editable s) {

            // filter your list from your input
            filter(s.toString());
            //you can use runnable postDelayed like 500 ms to delay search text
        }
    });

Semplice funzione di filtro

void filter(String text){
     List temp = new ArrayList();
     for(DataHolder d: displayedList){
           //or use .equal(text) with you want equal match
           //use .toLowerCase() for better matches
           if(d.getEnglish().contains(text)){
               temp.add(d);
           }
     }
     //update recyclerview
     disp_adapter.updateList(temp);
}

Con Butterknife

@OnTextChanged(R.id.feature_manager_search)
protected void onTextChanged(CharSequence text) {
    filter(text.toString());
}

ho fatto così

File .XMl






    








File di classe .JAVA

package com.example.myapplication;

import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.CardView;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Filter;
import android.widget.Filterable;
import android.widget.ImageView;
import android.widget.TextView;

import org.json.JSONObject;

import java.util.ArrayList;

public class Home extends AppCompatActivity implements ResultCallBack{

SQLiteDatabase db;

ArrayList alCategorName=new ArrayList<>();

RecyclerView rvCategory;
EditText etSearch;
Category bookadapter;
ArrayList alBookInfo;

String strURL="http://localhost:21246/api/TreasuryBooks?BookId=1";

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

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    toolbar.setTitleTextColor(getResources().getColor(R.color.white));
    setSupportActionBar(toolbar);

//        AsyncTask_WebAPI asyncTask=new AsyncTask_WebAPI(this,strURL,this);
//        asyncTask.execute();

    etSearch=(EditText)findViewById(R.id.etSearch);
    etSearch.setText("");

    DatabaseAccess da= DatabaseAccess.getInstance(this);
    db=da.open();
    alBookInfo=new ArrayList();

    Cursor c = db.rawQuery("select BookName from Books", null);
    int rows = c.getCount();

    c.moveToFirst();

    for(int i=0;i

Adattatore Recyclerview

  //Recycler view adapter Class with filterable interface

   private class Category extends RecyclerView.Adapter implements Filterable
{
    ArrayList alBooks=new ArrayList();
    Context context;
    viewHolder holder;

    public  Category()
    {}

    public Category(Context context,ArrayList albooks)
    {
        this.context=context;
        this.alBooks=albooks;
    }

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

    @Override
    public viewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View v=    LayoutInflater.from(parent.getContext()).inflate(R.layout.home_cardview,parent,false);
        holder=new viewHolder(v);
        return holder;
    }

    @Override
    public void onBindViewHolder(viewHolder holder, int position) {
        holder.tvBookName.setText(alBooks.get(position));
    }

    private Filter fRecords;

   //return the filter class object
    @Override
    public Filter getFilter() {
        if(fRecords == null) {
            fRecords=new RecordFilter();
        }
        return fRecords;
    }

   //filter class
    private class RecordFilter extends Filter {

        @Override
        protected FilterResults performFiltering(CharSequence constraint) {

            FilterResults results = new FilterResults();

            //Implement filter logic
    // if edittext is null return the actual list
            if (constraint == null || constraint.length() == 0) {
                //No need for filter
                results.values = alBookInfo;
                results.count = alBookInfo.size();

            } else {
               //Need Filter
        // it matches the text  entered in the edittext and set the data in adapter list
                ArrayList fRecords = new ArrayList();

                for (String s : alBookInfo) {
                    if (s.toUpperCase().trim().contains(constraint.toString().toUpperCase().trim())) {
                        fRecords.add(s);
                    }
                }
                results.values = fRecords;
                results.count = fRecords.size();
            }
            return results;
        }

        @Override
        protected void publishResults(CharSequence constraint,FilterResults results) {

       //it set the data from filter to adapter list and refresh the recyclerview adapter
            alBooks = (ArrayList) results.values;
            notifyDataSetChanged();
           }
       }
   }

   private class viewHolder extends  RecyclerView.ViewHolder {
    CardView cv;
    TextView tvBookName;

    viewHolder(final View itemview) {
        super(itemview);

        cv = (CardView) itemview.findViewById(R.id.cardview);
        tvBookName = (TextView) itemview.findViewById(R.id.categoryName);

        itemview.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new       Intent(Home.this,Act_Fragment_Container.class);
                intent.putExtra("BookName", tvBookName.getText());
                startActivity(intent);
            }
        });
    }
   }

}

aggiungere l'adattatore della vista riciclatrice nella stessa classe per evitare confusione....

Implementare SearchView.OnQueryTextListener

public class Countries_List extends AppCompatActivity  implements SearchView.OnQueryTextListener {

    //your Model Class

    List dataList, filteredDataList;

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main, menu);
        MenuItem item=menu.findItem(R.id.action_search);
        SearchView searchView=(SearchView)MenuItemCompat.getActionView(item);
        searchView.setOnQueryTextListener(this);

        return true;
    }
    @Override
    public boolean onQueryTextSubmit(String query) {
        return false;
    }

    @Override
    public boolean onQueryTextChange(String newText) {

        filteredDataList = filter(dataList, newText);
        mAdapter.setFilter(filteredDataList);
        return true;
    }
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_search) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
    private List filter(List dataList, String newText) {
        newText=newText.toLowerCase();
        String text;
        filteredDataList=new ArrayList<>();
        for(Countries dataFromDataList:dataList){
            text=dataFromDataList.getTitle().toLowerCase();

            if(text.contains(newText)){
                filteredDataList.add(dataFromDataList);
            }
        }

        return filteredDataList;
    }
}

E, nella classe adattatore:

void setFilter(List FilteredDataList) {
        countriesList = FilteredDataList;
        notifyDataSetChanged();
    }



Utilizzate il nostro motore di ricerca

Ricerca
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