Android實現ListView過濾功能之繼承BaseAdapter進階版

實現ListView過濾功能最方便的便是使用ArrayAdapter，裡面自帶的getFilter()方法能很方便的實現此功能

但是在實際的開發中，ArrayAdapter有的時候滿足不了我們項目的各種需求，所以一般都是繼承於BaseAdapter，然後繼承BaseAdapter不能像ArrayAdapter那樣直接通過ListView的setTextFilter()就對ListView進行簡單的過濾，我們需要去手動實現一個Filterable接口，自定義過濾規則；

接下來直接上代碼了
* 首先是布局文件<喎?/kf/ware/vc/" target="_blank" class="keylink">vcD4NCjxwcmUgY2xhc3M9"brush:java;">

視圖布局就是

* SearchFragment.java

/**
 * @author鄭明亮    @email [email protected]
 * @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";

    Listdata = null;
    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;
    RecomendAdapter adapter = null;

    private OnFragmentInteractionListener mListener;

    AutoClearEditText et_search;//我自定義的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);
        //暫時模擬填充數據
        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); // 開啟過濾功能
        ib_search.setOnClickListener(this);
        //為EditText（搜素框）設置一個TextWatcher來監視輸入的動作
        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();//搜索文本為空時，清除ListView的過濾
                else
                search_list.setFilterText(charSequence.toString().trim());//設置過濾關鍵字
            }

            @Override
            public void afterTextChanged(Editable editable) {

            }
        });

    }

    private void initData(){
        data = new ArrayList<>();
        data.add(new Recomend("應用推薦","忙碌一天的你，怎麼能沒有一款好玩的游戲來放松一下呢"));
        data.add(new Recomend("好書推薦","讀過一本好書，像交了一個益友。——臧克家"));
        data.add(new Recomend("養生推薦","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("資訊推薦","風聲雨聲讀書聲，聲聲入耳；家事國事天下事，事事關心，快來看看吧"));
        data.add(new Recomend("更多推薦","吃喝玩樂學一應俱全，快來看看吧"));
        data.add(new Recomend("更多推薦","吃喝玩樂學一應俱全，快來看看吧"));
        data.add(new Recomend("更多推薦","吃喝玩樂學一應俱全，快來看看吧"));
        data.add(new Recomend("更多推薦","吃喝玩樂學一應俱全，快來看看吧"));
        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();//搜索文本為空時，過濾設置
                }else {
//                    search_list.clearTextFilter();
                    search_list.setFilterText(search);//設置過濾關鍵字
                }


                break;
            default:
                break;
        }
    }

}

我在注釋中已經注明了，需要注意的地方就是一定要先打開過濾功能 search_list.setTextFilterEnabled(true)
* 接下來是適配器的代碼，關鍵代碼；

/**
 * @author 鄭明亮   @email [email protected]
 * @version 1.0
 * @time 2016/7/29 18:28
 * TODO
 */
public class RecomendAdapter extends BaseAdapter implements Filterable{
    Context context;
    List data; //這個數據是會改變的，所以要有個變量來備份一下原始數據
    List backData;//用來備份原始數據
    MyFilter mFilter ;

    public RecomendAdapter(Context context, List 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;
    }
    //當ListView調用setTextFilter()方法的時候，便會調用該方法
    @Override
    public Filter getFilter() {
        if (mFilter ==null){
            mFilter = new MyFilter();
        }
        return mFilter;
    }
    //我們需要定義一個過濾器的類來定義過濾規則
     class MyFilter extends Filter{
     //我們在performFiltering(CharSequence charSequence)這個方法中定義過濾規則
        @Override
        protected FilterResults performFiltering(CharSequence charSequence) {
            FilterResults result = new FilterResults();
            List list ;
              if (TextUtils.isEmpty(charSequence)){//當過濾的關鍵字為空的時候，我們則顯示所有的數據
                list  = backData;
            }else {//否則把符合條件的數據對象添加到集合中
                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; //將得到的集合保存到FilterResults的value變量中
            result.count = list.size();//將集合的大小保存到FilterResults的count變量中

            return result;
        }
    //在publishResults方法中告訴適配器更新界面
        @Override
        protected void publishResults(CharSequence charSequence, FilterResults filterResults) {
            data = (List)filterResults.values;
            LogUtil.d("publishResults:"+filterResults.count);
            if (filterResults.count>0){
                notifyDataSetChanged();//通知數據發生了改變
                LogUtil.d("publishResults:notifyDataSetChanged");
            }else {
                notifyDataSetInvalidated();//通知數據失效
                LogUtil.d("publishResults:notifyDataSetInvalidated");
            }
        }
    }
}