Android实现模拟搜索功能

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="Http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".SearchBoxActivity"
    android:orientation="vertical"
    >
    <EditText
        android:id="@+id/et_search"
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:hint="搜索名称"
        android:background="@drawable/btn_search"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:layout_marginTop="10dp"
        android:maxLines="1"
        android:maxLength="20"
        android:inputType="text"
        android:drawableLeft="@drawable/search"
        />
    <ListView
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        />
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <padding
        android:bottom="5dp"
        android:left="5dp"
        android:right="5dp"
        android:top="5dp" />
    <stroke
        android:width="2dp"
        android:color="@color/blue" />
    <solid android:color="@color/white" />
    <corners android:radius="20dp" />
</shape>

public class SearchAdapter extends BaseAdapter implements Filterable {
    private Context context;
    private ArrayList<Simulation> list = new ArrayList<>();
    private MyFilter filter; //创建MyFilter对象
    private FilterListener listener = null; //接口对象

    public SearchAdapter(Context context, ArrayList<Simulation> list, FilterListener listener) {
        this.context = context;
        this.list = list;
        this.listener = listener;
    }

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

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

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        try {
            final ViewHold hold;
            if (convertView == null) {
                hold = new ViewHold();
                convertView = LayoutInflater.from(context).inflate(R.layout.item_search, null);
                hold.tv_simulation = convertView.findViewById(R.id.tv_simulation);
                convertView.setTag(hold);
            } else {
                hold = (ViewHold) convertView.getTag();
            }
            Simulation simulation = list.get(position);
            hold.tv_simulation.setText(simulation.getText());
        } catch (Exception e) {
            e.printStackTrace();
        }
        return convertView;
    }

    public Filter getFilter() {
        if (filter == null) {
            filter = new MyFilter(list);
        }
        return filter;
    }

    
    class MyFilter extends Filter {
        //创建集合保存原始数据
        private ArrayList<Simulation> original = new ArrayList<>();

        public MyFilter(ArrayList<Simulation> original) {
            this.original = original;
        }

        //该方法返回搜索过滤后的数据
        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            //创建FilterResults对象
            FilterResults filterResults = new FilterResults();
            
            if (TextUtils.isEmpty(constraint)) {
                //取出当前的数据源的值和集合元素个数
                //此时返回的filterResults就是原始的数据，不进行过滤
                filterResults.values = original;
                filterResults.count = original.size();
            } else {
                ArrayList<Simulation> mList = new ArrayList<>();
                //创建集合保护过滤后的数据
                for (Simulation s : original) {
                    //这里的toLowerCase():是将字符串中的字母全部变为小写，而非字母则不做改变
                    if (s.getText().trim().toLowerCase().contains(constraint.toString().trim().toLowerCase())) {
                        //规则匹配的话就往集合中添加该数据
                        mList.add(s);
                    }
                }
                filterResults.values = mList;
                filterResults.count = mList.size();
            }
            return filterResults;
        }

        //该方法用来刷新用户界面，根据过滤后的数据重新展示列表
        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) {
            //获取过滤后的数据
            list = (ArrayList<Simulation>) results.values;
            //如果接口对象不为空，那么调用接口中的方法获取过滤后的数据，具体的实现在new这个接口的时候重写的方法里执行
            if (listener != null) {
                listener.getFilterData(list);
            }
            //刷新数据源显示
            //通知数据观察者当前所关联的数据源已经发生改变，任何与该数据有关的视图都应该去刷新自己。
            notifyDataSetChanged();
        }
    }

    public interface FilterListener{
        void getFilterData(List<Simulation> list);
    }

    public final class ViewHold {
        private TextView tv_simulation;
    }

}

public class SearchBoxActivity extends AppCompatActivity {
    private static final String TAG = "SearchBoxActivity";
    private EditText et_search;
    private ListView listView;
    private SearchAdapter searchAdapter;

    private ArrayList<Simulation> list = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_search_box);
        et_search = findViewById(R.id.et_search);
        listView = findViewById(R.id.listView);
        String data[] = new String[]{"大数据", "Android开发", "Java开发", "WEB前端开发", "网页开发", "iOS开发"};
        for (int i = 0; i < 6; i++) {
            Simulation simulation = new Simulation(data[i]);
            list.add(simulation);
        }

        searchAdapter = new SearchAdapter(this, list, new SearchAdapter.FilterListener() {
            @Override
            public void getFilterData(List<Simulation> list) {
                //这里可以拿到过滤后的数据，所以在这里可以对搜索后的数据进行操作
                Log.e(TAG, "接口回调成功");
                Log.e(TAG, list.toString());
                setItemClick(list);
            }
        });
        //设置适配器
        listView.setAdapter(searchAdapter);
        //设置监听
        setListeners();
    }

    private void setListeners() {
        //没有进行搜索的时候，也要添加对listView的item单击监听
        setItemClick(list);
        
        et_search.addTextChangedListener(new TextWatcher() {
            //每次EditText文本改变之前的时候，会回调这个方法
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
                //s     输入框中改变前的字符串信息
                //start 输入框中改变前的字符串的起始位置
                //count 输入框中改变前后的字符串改变数量一般为0
                //after 输入框中改变后的字符串与起始位置的偏移量
            }
            //每次EditText文本改变的时候，会回调这个方法
            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                //第一个参数s 的含义: 输入框中改变后的字符串信息
                //start 输入框中改变后的字符串的起始位置
                //before 输入框中改变前的字符串的位置 默认为0
                //count 输入框中改变后的一共输入字符串的数量
                if (searchAdapter != null) {
                    searchAdapter.getFilter().filter(s);
                }
            }
            //每次EditText文本改变之后的时候，会回调这个方法
            @Override
            public void afterTextChanged(Editable s) {
                //edit  输入结束呈现在输入框中的信息
            }
        });
    }

    private void setItemClick(List<Simulation> filter_list) {
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Toast.makeText(SearchBoxActivity.this, filter_list.get(position).getText(), Toast.LENGTH_SHORT).show();
            }
        });
    }
}