列表数据搜索

package com.example.testapplication;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;

import androidx.annotation.Nullable;

import com.example.testapplication.adapter.ListViewAdapter;
import com.example.testapplication.entity.Food;

import java.util.ArrayList;
import java.util.List;

public class FoodListActivity extends ApplicationActivity{
    ListView listView;
    List foodList = new ArrayList<>();
    List selectedList = new ArrayList<>();
    EditText editText;
    Button button;
    ListViewAdapter listViewAdapter;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_food_list);
        listView = findViewById(R.id.list_view);
        button = findViewById(R.id.buttonfood);
        editText = findViewById(R.id.edit_text);
        foodList.add(new Food("麻辣香锅", 55));
        foodList.add(new Food("水煮鱼", 48));
        foodList.add(new Food("麻辣火锅", 80));
        foodList.add(new Food("清蒸鲈鱼", 68));
        foodList.add(new Food("桂林米粉", 15));
        foodList.add(new Food("上汤娃娃菜", 28));
        foodList.add(new Food("红烧肉", 60));
        foodList.add(new Food("木须肉", 40));
        foodList.add(new Food("酸菜牛肉面", 35));
        foodList.add(new Food("西芹炒百合", 38));
        foodList.add(new Food("酸辣汤", 40));
        foodList.add(new Food("酸辣汤", 40));
        foodList.add(new Food("酸辣汤", 40));
        foodList.add(new Food("酸辣汤", 40));
        selectedList.addAll(foodList);
        listViewAdapter = new ListViewAdapter(selectedList,this);
        listView.setAdapter(listViewAdapter);

        button.setonClickListener(new View.onClickListener() {
            @Override
            public void onClick(View view) {
                try {
                    int price = Integer.parseInt(editText.getText().toString());
                    selectedList.clear();
                    for (Food unit:foodList){
                        if(unit.getPrice() <= price){
                            selectedList.add(unit);
                        }
                    }
                    listViewAdapter.notifyDataSetChanged();
                }catch (Exception e){
                    Toast.makeText(FoodListActivity.this,"请输入正确价格",Toast.LENGTH_SHORT).show();
                }
            }
        });





    }
}

package com.example.testapplication.adapter;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.baseAdapter;
import android.widget.TextView;

import com.example.testapplication.R;
import com.example.testapplication.entity.Food;

import java.util.List;

public class ListViewAdapter extends baseAdapter {
    private List foodList;
    private LayoutInflater layoutInflater;

    public ListViewAdapter(List foodList, Context context){
        this.foodList = foodList;
        this.layoutInflater = LayoutInflater.from(context);
    }
    @Override
    public int getCount() {
        return foodList.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) {
        ViewHoler viewHoler;
        if(view == null){
            view = layoutInflater.inflate(R.layout.item_food,viewGroup,false);
            viewHoler = new ViewHoler();
            viewHoler.name = view.findViewById(R.id.name_tv);
            viewHoler.price = view.findViewById(R.id.price_tv);
            view.setTag(viewHoler);
        }else{
            viewHoler = (ViewHoler) view.getTag();
        }
        viewHoler.name.setText(foodList.get(i).getName());
        viewHoler.price.setText(String.valueOf(foodList.get(i).getPrice()+"元"));
        return view;
    }

    class ViewHoler{
        TextView name;
        TextView price;
    }
}