Android实现ListView过滤功能之继承BaseAdap

作者：zml_2015
原文：https://blog.csdn.net/zml_2015/article/details/52082174

实现ListView过滤功能最方便的便是使用ArrayAdapter，里面自带的getFilter()方法能很方便的实现此功能

但是在实际的开发中，ArrayAdapter有的时候满足不了我们项目的各种需求，所以一般都是继承于BaseAdapter，然后继承BaseAdapter不能像ArrayAdapter那样直接通过ListView的setTextFilter()就对ListView进行简单的过滤，我们需要去手动实现一个Filterable接口，自定义过滤规则；
效果图

image.png image.png

接下来直接上代码了

• 首先是布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:background="@color/white"
              android:orientation="vertical"
    >

    <LinearLayout
        android:id="@+id/search_top_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:background="@color/blue_title_bg"
        android:gravity="center_vertical"
        android:orientation="horizontal" >


        <com.zml.collrec.view.AutoClearEditText
            android:id="@+id/search_edit"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_margin="5dp"
            android:layout_weight="1"
            android:background="@drawable/search_box"
            android:drawableRight="@drawable/app_icon_voice"
            android:focusable="true"
            android:hint="搜索"
            android:padding="6dp"
            android:singleLine="true"
            android:textColor="@color/black"
            android:textSize="@dimen/micro_text_size" />

        <ImageButton
            android:id="@+id/search_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="5dp"
            android:background="#035AB2"
            android:paddingLeft="10dp"
            android:paddingRight="10dp"
            android:src="@mipmap/android_search_icon" />
    </LinearLayout>

    <ListView
        android:id="@+id/search_list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@id/search_top_layout"
        android:divider="@null"
        android:dividerHeight="1dp"
        android:listSelector="@null"
        android:scrollbars="none"
         />

    </LinearLayout>

布局视图

image.png

 
* SearchFragment.java

/**
 * @author郑明亮    @email 1072307340@qq.com
 * @Time：2016/8/1 1:35
 * @version 1.0
 * TODO
 */public class SearchFragment extends Fragment implements AdapterView.OnItemClickListener, View.OnClickListener {

    // TODO: Rename parameter arguments, choose names that match
    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";

    List<Recomend>data = null;
    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;
    RecomendAdapter adapter = null;

    private OnFragmentInteractionListener mListener;

    AutoClearEditText et_search;//我自定义的EditText
    ImageButton ib_search;
    ListView search_list;



    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @param param1 Parameter 1.
     * @param param2 Parameter 2.
     * @return A new instance of fragment SearchFragment.
     */
    // TODO: Rename and change types and number of parameters
    public static SearchFragment newInstance(String param1, String param2) {
        SearchFragment fragment = new SearchFragment();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_search, container, false);

        initView(view);
        //暂时模拟填充数据
        initData();
        return view;
    }

    private void initView(View view) {
        ib_search = (ImageButton) view.findViewById(R.id.search_button);
        et_search = (AutoClearEditText) view.findViewById(R.id.search_edit);
        search_list = (ListView) view.findViewById(R.id.search_list);
        search_list.setTextFilterEnabled(true); // 开启过滤功能
        ib_search.setOnClickListener(this);
        //为EditText（搜素框）设置一个TextWatcher来监视输入的动作
        et_search.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

            }

            @Override
            public void onTextChanged(CharSequence charSequence, int start, int before, int count) {
                if (TextUtils.isEmpty(charSequence.toString().trim()))
                    search_list.clearTextFilter();//搜索文本为空时，清除ListView的过滤
                else
                search_list.setFilterText(charSequence.toString().trim());//设置过滤关键字
            }

            @Override
            public void afterTextChanged(Editable editable) {

            }
        });

    }

    private void initData(){
        data = new ArrayList<>();
        data.add(new Recomend("应用推荐","忙碌一天的你，怎么能没有一款好玩的游戏来放松一下呢"));
        data.add(new Recomend("好书推荐","读过一本好书，像交了一个益友。——臧克家"));
        data.add(new Recomend("养生推荐","三天不吃青，兩眼冒金星。寧可食無肉，不可飯無湯。吃面多喝湯，免得開藥方"));
        data.add(new Recomend("资讯推荐","风声雨声读书声，声声入耳；家事国事天下事，事事关心，快来看看吧"));
        data.add(new Recomend("更多推荐","吃喝玩乐学一应俱全，快来看看吧"));
        data.add(new Recomend("更多推荐","吃喝玩乐学一应俱全，快来看看吧"));
        data.add(new Recomend("更多推荐","吃喝玩乐学一应俱全，快来看看吧"));
        data.add(new Recomend("更多推荐","吃喝玩乐学一应俱全，快来看看吧"));
        adapter = new RecomendAdapter(getActivity(),data);
        search_list.setAdapter(adapter);
        search_list.setOnItemClickListener(this);
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
    }

    @Override
    public void onDetach() {
        super.onDetach();
    }

    @Override
    public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
        ScreenUtils.showToast(data.get(i).getTitle());
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.search_button:
                String search = et_search.getText().toString().trim();
                if (TextUtils.isEmpty(search)){
                    search_list.clearTextFilter();//搜索文本为空时，过滤设置
                }else {
//                    search_list.clearTextFilter();
                    search_list.setFilterText(search);//设置过滤关键字
                }


                break;
            default:
                break;
        }
    }

}

我在注释中已经注明了，需要注意的地方就是一定要先打开过滤功能 search_list.setTextFilterEnabled(true)

• 接下来是适配器的代码，关键代码；

/**
 * @author 郑明亮   @email 1072307340@qq.com
 * @version 1.0
 * @time 2016/7/29 18:28
 * TODO
 */
public class RecomendAdapter extends BaseAdapter implements Filterable{
    Context context;
    List<Recomend> data; //这个数据是会改变的，所以要有个变量来备份一下原始数据
    List<Recomend> backData;//用来备份原始数据
    MyFilter mFilter ;

    public RecomendAdapter(Context context, List<Recomend> data) {
        this.context = context;
        this.data = data;
        backData = data;
    }

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

    @Override
    public Object getItem(int i) {
        return null;
    }

    @Override
    public long getItemId(int i) {
        return 0;
    }

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {

        if (view ==null){
            view = LayoutInflater.from(context).inflate(R.layout.fragment_recomend_item,null);
       }
        TextView tv_title = ViewHolder.get(view,R.id.tv_recomend_title);
        TextView tv_desc = ViewHolder.get(view,R.id.tv_recomend_desc);
        ImageView img = ViewHolder.get(view,R.id.iv_recomend_img);
        tv_title.setText(data.get(i).getTitle());
        tv_desc.setText(data.get(i).getDesc());
        Glide.with(context).load(R.drawable.default_head_icon).asBitmap().centerCrop().placeholder(R.mipmap.ic_launcher).into(img);
        return view;
    }
    //当ListView调用setTextFilter()方法的时候，便会调用该方法
    @Override
    public Filter getFilter() {
        if (mFilter ==null){
            mFilter = new MyFilter();
        }
        return mFilter;
    }
    //我们需要定义一个过滤器的类来定义过滤规则
     class MyFilter extends Filter{
     //我们在performFiltering(CharSequence charSequence)这个方法中定义过滤规则
        @Override
        protected FilterResults performFiltering(CharSequence charSequence) {
            FilterResults result = new FilterResults();
            List<Recomend> list ;
              if (TextUtils.isEmpty(charSequence)){//当过滤的关键字为空的时候，我们则显示所有的数据
                list  = backData;
            }else {//否则把符合条件的数据对象添加到集合中
                list = new ArrayList<>();
                for (Recomend recomend:backData){
                    if (recomend.getTitle().contains(charSequence)||recomend.getDesc().contains(charSequence)){
                        LogUtil.d("performFiltering:"+recomend.toString());
                        list.add(recomend);
                    }

                }
            }
            result.values = list; //将得到的集合保存到FilterResults的value变量中
            result.count = list.size();//将集合的大小保存到FilterResults的count变量中

            return result;
        }
    //在publishResults方法中告诉适配器更新界面
        @Override
        protected void publishResults(CharSequence charSequence, FilterResults filterResults) {
            data = (List<Recomend>)filterResults.values;
            LogUtil.d("publishResults:"+filterResults.count);
            if (filterResults.count>0){
                notifyDataSetChanged();//通知数据发生了改变
                LogUtil.d("publishResults:notifyDataSetChanged");
            }else {
                notifyDataSetInvalidated();//通知数据失效
                LogUtil.d("publishResults:notifyDataSetInvalidated");
            }
        }
    }
}

最后用search_list.setFilterText(search);//设置过滤关键字 会出现如效果图出现的黑色的框
可以使用adapter.getFilter().filter(s)就不会有那个框框了 。