android - 过滤ListView后无法获取项目的实际位置

Question

这是我的 MainActivity.java，我在其中为项目定义了一个 OnClickListener。在这里，过滤后我总是得到错误的项目值。

如果 ListView 中有 10 个项目，那么在过滤后如果我得到 3 个项目并且正确的位置是 3,6,9 那么我得到的是 0,1,2。

package com.focusmedica.maadiabetes;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.MotionEvent;
import android.view.View;
import android.view.WindowManager;
import android.widget.AdapterView;
import android.widget.EditText;
import android.widget.ListView;

import java.util.ArrayList;

public class MainActivity extends Activity {

private MainAdapter adapter;
private static ListView lvFiltered;
private static ArrayList<DataModel> data=new ArrayList<>();;
MyDatabase handler;
private EditText etSearch;

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

    lvFiltered =(ListView)findViewById(R.id.lvFiltered);
    etSearch = (EditText)findViewById(R.id.etSearch);
    etSearch.setText("");
    getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_HIDDEN);

    handler=new MyDatabase(this);

    data=handler.getChapterDetails();
    adapter = new MainAdapter(this,data);
    lvFiltered.setAdapter(adapter);
    lvFiltered.setTextFilterEnabled(true);

    lvFiltered.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Intent intent = new Intent(MainActivity.this, SubActivity.class);
            intent.putExtra("position", position);
            startActivity(intent);
        }
    });

    etSearch.addTextChangedListener(new TextWatcher() {
        @Override
        public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
            if(cs.length()>0) {
                etSearch.setCompoundDrawablesWithIntrinsicBounds(0, 0, R.drawable.delete, 0);
            }else{
                etSearch.setCompoundDrawablesWithIntrinsicBounds(0, 0, 0, 0);
            }
            // When user changed the Text
            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
        }
    });

    etSearch.setOnTouchListener(new View.OnTouchListener() {
        @SuppressLint("ClickableViewAccessibility")
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            if(event.getAction() == MotionEvent.ACTION_UP) {
                if(etSearch.getCompoundDrawables()[2]!=null){
                    if(event.getX() >= (etSearch.getRight()- etSearch.getLeft() - etSearch.getCompoundDrawables()[2].getBounds().width())) {
                        etSearch.setText("");
                    }
                }
            }
            return false;
        }
    });
  }
}

这里是适配器类

package com.focusmedica.maadiabetes;

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

import java.util.ArrayList;

/**
 * Created by windev on 8/2/2016.
 */

public class MainAdapter extends BaseAdapter implements Filterable {

ArrayList<DataModel> dataSet;
Context context;
DataModel content;
public ArrayList<DataModel> orig;

public MainAdapter(Context context, ArrayList dataSet) {
    super();
    this.context = context;
    this.dataSet = dataSet;
}


@Override
public int getCount() {
    return dataSet.size();
}

@Override
public Object getItem(int position) {
    return dataSet.get(position);
}

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

class ViewHolder {
    private TextView tvChapterName;
    private ImageView ivChapterIcon;
}

@Override
public View getView(int position, View view, ViewGroup viewGroup) {
    final ViewHolder viewHolder;
    if (view == null) {
        LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        view = inflater.inflate(R.layout.card_layout, null);
        viewHolder = new ViewHolder();
        viewHolder.tvChapterName = (TextView) view.findViewById(R.id.tvChapterName);
        viewHolder.ivChapterIcon=(ImageView)view.findViewById(R.id.ivChapterIcon);
        view.setTag(viewHolder);
    } else {
        viewHolder = (ViewHolder) view.getTag();
    }
    content = dataSet.get(position);
    viewHolder.tvChapterName.setText(content.getChapterName());
    viewHolder.ivChapterIcon.setImageResource(R.drawable.caticon);
    return view;
}

public Filter getFilter() {
    return new Filter() {

        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            final FilterResults oReturn = new FilterResults();
            final ArrayList<DataModel> results = new ArrayList<>();
            final ArrayList<DataModel> ids = new ArrayList<>();
            if (orig == null)
                orig = dataSet;
            if (constraint != null) {
                if (orig != null && orig.size() > 0) {
                    for (final DataModel g : orig) {
                        if (g.getChapterName().toLowerCase().contains(constraint.toString())||
                                g.getChapterName().toUpperCase().contains(constraint.toString()))
                            results.add(g);
                    }
                }
                oReturn.values = results;
            }
            return oReturn;
        }

        @SuppressWarnings("unchecked")
        @Override
        protected void publishResults(CharSequence constraint,
                                      FilterResults results) {
            dataSet = (ArrayList<DataModel>) results.values;
            notifyDataSetChanged();
        }
    };
}

public void notifyDataSetChanged() {
    super.notifyDataSetChanged();
}
}

Answer 1

获取筛选列表中项目的“旧”位置(相当于项目 ID):

@Override
public long getItemId(int position) {

    int itemID;

    // orig will be null only if we haven't filtered yet:
    if (orig == null)
    {
        itemID = position;
    }
    else
    {
        itemID = orig.indexOf(dataSet.get(position));
    }
    return itemID;
}

现在将此方法与 OnItemClickListener 一起使用:

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        Intent intent = new Intent(MainActivity.this, SubActivity.class);
        intent.putExtra("position", adapter.getItemId(position) );
        startActivity(intent);
    }

注意:如果您需要使用 notifyDatasetChanged()，最好也覆盖此方法:

@Override
public void notifyDatasetChanged()
{
    // either this or: orig = dataSet;
    orig = null;
    super.notifyDatasetChanged();
}