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android - 带有过滤器 Android 的自定义 Listview 适配器

coder 2023-05-08 原文

请尝试在我的 ListView 上实现过滤器。但是每当文本更改时,列表就会消失。请帮助 这是我的代码。适配器类。

package com.talagbe.schymn;

import java.util.ArrayList;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

public class HymnsAdapter extends ArrayAdapter<Hymns> {
ArrayList<Hymns> hymnarray;
Context context;
LayoutInflater inflater;
int Resource;


public HymnsAdapter(Context context, int resource, ArrayList<Hymns> objects) {
    super(context, resource, objects);
    // TODO Auto-generated constructor stub

    hymnarray=objects;
    Resource= resource;
    this.context=context;
    inflater= (LayoutInflater) context.getSystemService(context.LAYOUT_INFLATER_SERVICE);
}


@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
     ViewHolder holder;
     if(convertView==null){

         convertView= inflater.inflate(Resource,null);
         holder= new ViewHolder();
         holder.hymntitle= (TextView) convertView.findViewById(R.id.Hymn_title);
        // holder.hymntext= (TextView) convertView.findViewById(R.id.Channel_name);


         convertView.setTag(holder);

     }else{
         holder=(ViewHolder)convertView.getTag();
     }

     holder.hymntitle.setText(hymnarray.get(position).getTitle());
     //holder.hymntext.setText(hymnarray.get(position).getText());

    return convertView;


}


   static class ViewHolder{

    public TextView hymntitle;
    public TextView hymntext;

}

 }

这是我尝试实现过滤器的另一个类。我有一个编辑文本,我在 textChangeListener 上实现

package com.talagbe.schymn;

import java.util.ArrayList;

import database.DatabaseHelper;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.EditText;
import android.widget.ListView;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.widget.AdapterView.OnItemClickListener;

 public class Home extends Fragment {

    private static final String DB_NAME = "schymn.sqlite";
    private static final String TABLE_NAME = "Hymns";
    private static final String Hymn_ID = "_id";
    private static final String Hymn_Title = "Title";
    private static final String Hymn_Text = "Text";
    private SQLiteDatabase database;

ListView list;
EditText search;
HymnsAdapter vadapter;
ArrayList<Hymns> HymnsList;
String url;
Context context=null;


public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    // TODO Auto-generated method stub
      return inflater.inflate(R.layout.index, container,false);
}


@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    list = (ListView)getActivity().findViewById(R.id.hymn_list);
    search = (EditText) getActivity().findViewById(R.id.search);
    HymnsList = new ArrayList<Hymns>();

    DatabaseHelper dbOpenHelper = new DatabaseHelper(getActivity(), DB_NAME);
    database = dbOpenHelper.openDataBase();

    fillHymns();
    //setUpList();

}



private void fillHymns() {
    Cursor hymnCursor = database.query(TABLE_NAME,
                                         new String[] 
                                         {Hymn_ID, Hymn_Title,Hymn_Text},
                                         null, null, null, null
                                         , Hymn_Title);
    hymnCursor.moveToFirst();
    if(!hymnCursor.isAfterLast()) {
        do {
            Hymns hy = new Hymns();
            hy.setTitle(hymnCursor.getString(1));
            hy.setText(hymnCursor.getString(2));
            HymnsList.add(hy);

        } while (hymnCursor.moveToNext());
    }
    hymnCursor.close();
     vadapter = new HymnsAdapter(getActivity().getApplicationContext(),R.layout.hymns,HymnsList);
    list.setAdapter(vadapter);

    list.setOnItemClickListener(new OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {

            Intent intent = new Intent(getActivity().getApplicationContext(), Hymn_Text.class);
            intent.putExtra("Title",HymnsList.get(position).getTitle());
            intent.putExtra("Text",HymnsList.get(position).getText());
            startActivity(intent);
            //Log.i("Text",HymnsList.get(position).getText());

        }








    });


    search.addTextChangedListener( new TextWatcher() {

        @Override
        public void onTextChanged(CharSequence cs, int start, int before, int count) {
            // TODO Auto-generated method stub
            if(count>0){


            }

        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count,
                int after) {
            // TODO Auto-generated method stub

        }

        @Override
        public void afterTextChanged(Editable s) {
            // TODO Auto-generated method stub
             Home.this.vadapter.getFilter().filter(s);
                Log.i("Changed",s.toString());
        }
    });
}




  }

日志,记录我输入的任何输入,但不显示 ListView 。谢谢你

最佳答案

您可以在您的适配器上使用 Filterable 接口(interface),请看下面的示例:

public class SearchableAdapter extends BaseAdapter implements Filterable {
    
    private List<String>originalData = null;
    private List<String>filteredData = null;
    private LayoutInflater mInflater;
    private ItemFilter mFilter = new ItemFilter();
    
    public SearchableAdapter(Context context, List<String> data) {
        this.filteredData = data ;
        this.originalData = data ;
        mInflater = LayoutInflater.from(context);
    }
 
    public int getCount() {
        return filteredData.size();
    }
 
    public Object getItem(int position) {
        return filteredData.get(position);
    }
 
    public long getItemId(int position) {
        return position;
    }
 
    public View getView(int position, View convertView, ViewGroup parent) {
        // A ViewHolder keeps references to children views to avoid unnecessary calls
        // to findViewById() on each row.
        ViewHolder holder;
 
        // When convertView is not null, we can reuse it directly, there is no need
        // to reinflate it. We only inflate a new View when the convertView supplied
        // by ListView is null.
        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.list_item, null);
 
            // Creates a ViewHolder and store references to the two children views
            // we want to bind data to.
            holder = new ViewHolder();
            holder.text = (TextView) convertView.findViewById(R.id.list_view);
 
            // Bind the data efficiently with the holder.
 
            convertView.setTag(holder);
        } else {
            // Get the ViewHolder back to get fast access to the TextView
            // and the ImageView.
            holder = (ViewHolder) convertView.getTag();
        }
 
        // If weren't re-ordering this you could rely on what you set last time
        holder.text.setText(filteredData.get(position));
 
        return convertView;
    }
    
    static class ViewHolder {
        TextView text;
    }
 
    public Filter getFilter() {
        return mFilter;
    }
 
    private class ItemFilter extends Filter {
        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            
            String filterString = constraint.toString().toLowerCase();
            
            FilterResults results = new FilterResults();
            
            final List<String> list = originalData;
 
            int count = list.size();
            final ArrayList<String> nlist = new ArrayList<String>(count);
 
            String filterableString ;
            
            for (int i = 0; i < count; i++) {
                filterableString = list.get(i);
                if (filterableString.toLowerCase().contains(filterString)) {
                    nlist.add(filterableString);
                }
            }
            
            results.values = nlist;
            results.count = nlist.size();
 
            return results;
        }
 
        @SuppressWarnings("unchecked")
        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) {
            filteredData = (ArrayList<String>) results.values;
            notifyDataSetChanged();
        }
 
    }
}

在您实例化适配器的 Activity 或 Fragment 中:

editTxt.addTextChangedListener(new TextWatcher() {
  
    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
        System.out.println("Text ["+s+"]");
        
        mSearchableAdapter.getFilter().filter(s.toString());                           
    }
     
    @Override
    public void beforeTextChanged(CharSequence s, int start, int count,
            int after) {
         
    }
     
    @Override
    public void afterTextChanged(Editable s) {
    }
});

这里是 original source 的链接和 another example

关于android - 带有过滤器 Android 的自定义 Listview 适配器,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/24769257/

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