Android实战简易教程-第四十七枪（ListView多选-实现点餐系统）

一般在外卖的选单中常常会用到ListView的多选，大家可以改进后加入自己的项目中。下面看一下代码：

一、代码

1.main.xml:（由一个ListView和一个Button组成）

<?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:orientation="vertical" >

    <ListView
        android:id="@+id/drink_list"
        android:layout_width="fill_parent"
        android:layout_height="0dp"
        android:layout_weight="1" >
    </ListView>

    <Button
        android:id="@+id/btn_commit"
        android:layout_width="match_parent"
        android:layout_height="58dp"
        android:text="确定" />

</LinearLayout>

2.item.xml:

<?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="#ffffff"
    android:orientation="horizontal" >

    <CheckBox
        android:id="@+id/check_box"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:clickable="false"
        android:focusable="false"
        android:focusableInTouchMode="true" />

    <ImageView
        android:id="@+id/food_imager"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:background="#ffffff" />

    <TextView
        android:id="@+id/food_name"
        android:layout_width="100dp"
        android:layout_height="50dp"
        android:text="咖啡"
        android:gravity="center_vertical"
        android:layout_marginLeft="10dp"
        android:textSize="18sp" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="50dp"
        android:text="单价：RMB  "
        android:paddingLeft="20dp"
        android:textSize="12sp" />

    <TextView
        android:id="@+id/price"
        android:layout_width="wrap_content"
        android:layout_height="50dp"
        android:paddingRight="10dp"
        android:text="18"
        android:layout_marginLeft="20dp"
        android:textSize="18sp" />

</LinearLayout>

3.Food.java:(bean类)

package com.example.info;

public class Food {

  public int food_img;
  public String food_name;
  public String food_price;
  public String text;

  public int getFood_img() {
    return food_img;
  }

  public void setFood_img(int food_img) {
    this.food_img = food_img;
  }

  public String getFood_name() {
    return food_name;
  }

  public void setFood_name(String food_name) {
    this.food_name = food_name;
  }

  public String getFood_price() {
    return food_price;
  }

  public void setFood_price(String food_price) {
    this.food_price = food_price;
  }

  public Food(int food_img, String food_name, String food_price) {
    super();
    this.food_img = food_img;
    this.food_name = food_name;
    this.food_price = food_price;
  }

  public Food() {
    super();
  }

  @Override
  public String toString() {
    return super.toString();
  }
}

4.MyListViewAdapter.java:

package com.example.adapter;

import java.util.ArrayList;
import java.util.HashMap;

import com.example.info.Food;
import com.example.listviewselectitem.R;

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

public class MyListViewAdapter extends BaseAdapter {
  // 填充数据的list
  private ArrayList<Food> foodlist;
  // 用来控制CheckBox的选中状况
  private static HashMap<Integer, Boolean> isSelected;
  // 上下文
  private Context context;
  // 用来导入布局
  private LayoutInflater inflater = null;

  // 构造器
  public MyListViewAdapter(ArrayList<Food> list, Context context) {
    this.context = context;
    this.foodlist = list;
    inflater = LayoutInflater.from(context);
    isSelected = new HashMap<Integer, Boolean>();
    // 初始化数据
    initDate();
  }

  // 初始化isSelected的数据
  private void initDate() {
    for (int i = 0; i < foodlist.size(); i++) {
      getIsSelected().put(i, false);
    }
  }

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

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

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

  @Override
  public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder holder = null;
    if (convertView == null) {
      // 获得ViewHolder对象
      holder = new ViewHolder();
      // 导入布局并赋值给convertview
      convertView = inflater.inflate(R.layout.item, null);
      holder.imageView = (ImageView) convertView
          .findViewById(R.id.food_imager);
      holder.txt1 = (TextView) convertView.findViewById(R.id.food_name);
      holder.txt2 = (TextView) convertView.findViewById(R.id.price);
      holder.cb = (CheckBox) convertView.findViewById(R.id.check_box);
      // 为view设置标签
      convertView.setTag(holder);
    } else {
      // 取出holder
      holder = (ViewHolder) convertView.getTag();
    }
    // 获取数据
    Food food = foodlist.get(position);

    // 将数据填充到当前convertView的对应控件中

    holder.imageView.setImageResource(food.food_img);
    holder.txt1.setText(food.food_name);
    holder.txt2.setText(food.food_price);
    // 设置list中TextView的显示
    // 根据isSelected来设置checkbox的选中状况
    holder.cb.setChecked(getIsSelected().get(position));
    return convertView;
  }

  public static HashMap<Integer, Boolean> getIsSelected() {
    return isSelected;
  }

  public static void setIsSelected(HashMap<Integer, Boolean> isSelected) {
    MyListViewAdapter.isSelected = isSelected;
  }

  public static class ViewHolder {
    public TextView txt1;
    public TextView txt2;
    public ImageView imageView;
    public CheckBox cb;
  }
}

5.MainActivity.java:

package com.example.listviewselectitem;

import java.util.ArrayList;
import java.util.HashMap;

import com.example.adapter.MyListViewAdapter;
import com.example.adapter.MyListViewAdapter.ViewHolder;
import com.example.info.Food;

import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.Window;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.ListView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;

public class MainActivity extends Activity implements OnClickListener,
    OnItemClickListener {

  private ListView listView;
  private Button ok;
  private ArrayList<Food> foods = new ArrayList<Food>();
  private MyListViewAdapter adapter;
  private CheckBox checkBox;

  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.activity_main);
    initView();// 初始化控件
    View view=LayoutInflater.from(this).inflate(R.layout.item, null);
    checkBox=(CheckBox)view.findViewById(R.id.check_box);

    initData();// 初始化虚拟数据

    adapter = new MyListViewAdapter(foods, getApplicationContext());
    listView.setAdapter(adapter);
  }

  /**
   * 初始化控件
   * */
  public void initView() {
    listView = (ListView) findViewById(R.id.drink_list);// listview列表控件
    ok = (Button) findViewById(R.id.btn_commit);// 确定按钮

    ok.setOnClickListener(this);
    listView.setOnItemClickListener(this);
  }

  /**
   * 初始化虚拟数据
   * */
  public void initData() {
    
    
    
    
    Class cls = R.drawable.class;//反射
    try {
      foods.add(new Food(cls.getDeclaredField("d1").getInt(null), "猕猴桃汁",
          "10"));
      foods.add(new Food(cls.getDeclaredField("d2").getInt(null), "橙汁",
          "12"));
      foods.add(new Food(cls.getDeclaredField("d3").getInt(null), "啤酒",
          "15"));
      foods.add(new Food(cls.getDeclaredField("d4").getInt(null), "葡萄汁",
          "10"));
      foods.add(new Food(cls.getDeclaredField("d5").getInt(null), "纯麦奶茶",
          "8"));
      foods.add(new Food(cls.getDeclaredField("d6").getInt(null), "薄荷汁",
          "10"));
      foods.add(new Food(cls.getDeclaredField("d7").getInt(null), "柠檬薄荷",
          "12"));
      foods.add(new Food(cls.getDeclaredField("d8").getInt(null), "椰子汁",
          "10"));
      foods.add(new Food(cls.getDeclaredField("d9").getInt(null), "珍珠奶茶",
          "9"));
      foods.add(new Food(cls.getDeclaredField("d10").getInt(null), "石榴汁",
          "10"));

    } catch (Exception e) {
      e.printStackTrace();
    }
  }

  /**
   * 按钮的点击事件处理
   * */
  @Override
  public void onClick(View v) {
    int mID = v.getId();
    switch (mID) {
    case R.id.btn_commit:
      myPrice();// 计算总价并输出
      break;
    
    }
  }

  /**
   * 计算总价格的方法
   * */
  public void myPrice() {
    HashMap<Integer, Boolean> map = MyListViewAdapter.getIsSelected();
    String str = "";
    int money = 0;
    for (int i = 0; i < map.size(); i++) {
      if (map.get(i)) {
        str += (i + " ");
        money += Integer.parseInt(foods.get(i).food_price);
      }
    }
    MyListViewAdapter.getIsSelected().get("");
    Toast.makeText(getApplicationContext(),
        "已选中了" + str + "项,总价钱为:" + money, Toast.LENGTH_SHORT).show();
  }

  /**
   * listview的item的选择的方法
   * */
  @Override
  public void onItemClick(AdapterView<?> parent, View view, int position,
      long id) {
    // 取得ViewHolder对象，这样就省去了通过层层的findViewById去实例化我们需要的cb实例的步骤
    ViewHolder holder = (ViewHolder) view.getTag();
    // 改变CheckBox的状态
    holder.cb.toggle();
    // 将CheckBox的选中状况记录下来
    MyListViewAdapter.getIsSelected().put(position, holder.cb.isChecked());

  }
}

二、运行实例

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