如何在BaseAdapter上实现getFilter？

Question

我试图在基础适配器上实现一个getFilter()来过滤掉List上的搜索结果.有没有关于如何实现getFilter()的示例？

MainActivity.java

   final AppInfoAdapter adapter = new AppInfoAdapter(this, Utilities.getSystemFilteredApplication(this), getPackageManager());


        public void onTextChanged(CharSequence s, int start, int before,
                int count) {
           adapter.getFilter().filter(s); //Filter from my adapter
           adapter.notifyDataSetChanged(); //Update my view
        }

AppInfoAdapter.java

package com.example.permission;

import java.util.List;

import android.content.Context;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.BaseAdapter;
import android.widget.Filter;
import android.widget.Filterable;
import android.widget.ImageView;
import android.widget.TextView;

public class AppInfoAdapter extends BaseAdapter implements Filterable{
    private Context mContext;
    private List mListAppInfo;
    PackageManager mPackManager;

    public AppInfoAdapter(Context c, List list, PackageManager pm) {
        mContext = c;
        mListAppInfo = list;
        mPackManager = pm;
    }

    public int getCount() {
        return mListAppInfo.size();
    }


    public Object getItem(int position) {
        return mListAppInfo.get(position);
    }


    public long getItemId(int position) {
        return position;
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        // get the selected entry
        ApplicationInfo entry = (ApplicationInfo) mListAppInfo.get(position);

        // reference to convertView
        View v = convertView;

        // inflate new layout if null
        if(v == null) {
            LayoutInflater inflater = LayoutInflater.from(mContext);
            v = inflater.inflate(R.layout.layout_appinfo, null);
        }

        // load controls from layout resources
        ImageView ivAppIcon = (ImageView)v.findViewById(R.id.ivIcon);
        TextView tvAppName = (TextView)v.findViewById(R.id.tvName);
        TextView tvPkgName = (TextView)v.findViewById(R.id.tvPack);

        // set data to display
        ivAppIcon.setImageDrawable(entry.loadIcon(mPackManager));
        tvAppName.setText(entry.loadLabel(mPackManager));
        tvPkgName.setText(entry.packageName);

        // return view
        return v;
    }

    public Filter getFilter() {
        // TODO Auto-generated method stub
        return null;
    }


}

编辑:编辑代码并添加完整的AppInfoAdapter.java

Answer 1

在你的适配器中,这个类在getfilter方法中使用它

//this is a simple class that filtering the ArrayList of strings used in adapter

public class filter_here extends Filter{

        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            // TODO Auto-generated method stub

            FilterResults Result = new FilterResults();
            // if constraint is empty return the original names
            if(constraint.length() == 0 ){
                Result.values = Original_Names;
                Result.count = Original_Names.size();
                return Result;
            }

            ArrayList<String> Filtered_Names = new ArrayList<String>();
            String filterString = constraint.toString().toLowerCase();
            String filterableString;

            for(int i = 0; i<Original_Names.size(); i++){
                filterableString = Original_Names.get(i);
                if(filterableString.toLowerCase().contains(filterString)){
                    Filtered_Names.add(filterableString);
                }
            }
            Result.values = Filtered_Names;
            Result.count = Filtered_Names.size();

            return Result;
        }

        @Override
        protected void publishResults(CharSequence constraint,FilterResults results) {
            // TODO Auto-generated method stub
            Names = (ArrayList<String>) results.values;
            notifyDataSetChanged();
        }

    }

在getfilter中从它返回实例

@Override
    public Filter getFilter() {
        // TODO Auto-generated method stub
        return filter;
    }

完整的例子

Answer 2

这几乎让我被杀了:)

1. 像这样实现你的BaseAdapter:

2. 在公共适配器类中定义List的ArrayList,它将包含原始列表的临时项.

   public class MyAdapter extends BaseAdapter implements Filterable{
   
       public static ArrayList<String> temporarylist;
       public static ArrayList<String> OriginalList;
       private Activity activity;
   
       public MyAdapter(Activity activity, ArrayList<String> OriginalList) {
            super();
            this.activity=activity;
            this.OriginalList = OriginalList;
            temporarylist=OriginalList;
   
       }
       .
       .
       .
   

3. 使用以下代码创建getFilter()方法[作为示例]:

   public Filter getFilter() {
       Filter filter = new Filter() {
   
       @SuppressWarnings("unchecked")
       @Override
       protected void publishResults(CharSequence constraint, FilterResults results) {
           temporarylist=(ArrayList<String>)results.values;
           notifyDataSetChanged();
       }
   
       @Override
       protected FilterResults performFiltering(CharSequence constraint) {
           FilterResults results = new FilterResults();
           ArrayList<String> FilteredList= new ArrayList<String>();
           if (constraint == null || constraint.length() == 0) {
               // No filter implemented we return all the list
               results.values = OriginalList;
               results.count = OriginalList.size();
           }
           else {
               for (int i = 0; i < OriginalList.size(); i++) {
                   String data = OriginalList.get(i);
                   if (data.toLowerCase().contains(constraint.toString()))  {
                       FilteredList.add(data);
                   }
               }
               results.values = FilteredList;
               results.count = FilteredList.size();
           }
           return results;
       }
   };
   return filter;
   }
   

最后在您的EditText活动中:

MyAdapter adapter;
ArrayList<String> items;


ListView list = (ListView) findViewById(R.id.list);
items = new ArrayList<String>();
for (int i=0;i<30;i++){
     items.add("Hello world "+String.valueof(i));
}
adapter = new GameAdapter(this, items);
list.setAdapter(adapter);


EditText inputSearch = (EditText) findViewById(R.id.Search_txt);
     inputSearch.addTextChangedListener(new TextWatcher() {

            @Override
            public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
                // When user changed the Text
                MyActivity.this.adapter.getFilter().filter(cs);
            }

            @Override
            public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
                    int arg3) {
                // TODO Auto-generated method stub

            }

            @Override
            public void afterTextChanged(Editable arg0) {
                // TODO Auto-generated method stub                          
            }
        });