Android实战简易教程-第五十一枪（ListView实现子控件的动态显示和隐藏、checkbox全选和反选）

前段时间写过一篇文章：Android实战简易教程-第四十七枪（ListView多选-实现点餐系统）有的同学留言建议，可不可以动态控制checkbox的显示和全选反选功能，我研究了一下，发现实现也比较容易，特写下此篇文章。学习就是要有发散思维，要举一反三，大家也可以根据我的实例进行改编，添加和删除一些功能，这样可以提高你对知识的认知!下面我们看一下代码：

1.main.xml:

2.item.xml:

3.javabean:

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 foodlist;
	// 用来控制CheckBox的选中状况
	private static HashMap isSelected;
	// 上下文
	private Context context;
	// 用来导入布局
	private LayoutInflater inflater = null;
	
	private Boolean isShow=false;

	// 构造器
	public MyListViewAdapter(ArrayList list, Context context,Boolean isShow) {
		this.context = context;
		this.foodlist = list;
		inflater = LayoutInflater.from(context);
		isSelected = new HashMap();
		this.isShow=isShow;
		// 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

		if(isShow){
			holder.cb.setVisibility(View.VISIBLE);
		}else {
			holder.cb.setVisibility(View.GONE);
		}
		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 getIsSelected() {
		return isSelected;
	}

	public static void setIsSelected(HashMap 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.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.ListView;
import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener, OnItemClickListener {

	private ListView listView;
	private Button ok, mSelectButton, mSelectAllButton, mCancelAllButton;
	private ArrayList foods = new ArrayList();
	private MyListViewAdapter adapter;
	private CheckBox checkBox;
	private int checkNum; // 记录选中的条目数量

	private ArrayList list;
	private Boolean isShow = false;
	private Handler handler = new Handler() {
		public void handleMessage(android.os.Message msg) {
			if (msg.what == 1) {
				adapter = new MyListViewAdapter(foods, getApplicationContext(), true);
				listView.setAdapter(adapter);
				isShow = true;
				mCancelAllButton.setVisibility(View.VISIBLE);
				mSelectAllButton.setVisibility(View.VISIBLE);
			} else if (msg.what == 0) {
				adapter = new MyListViewAdapter(foods, getApplicationContext(), false);
				listView.setAdapter(adapter);
				isShow = false;
				mCancelAllButton.setVisibility(View.GONE);
				mSelectAllButton.setVisibility(View.GONE);
			}
		};
	};

	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(), false);
		isShow = false;
		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

		list = new ArrayList();
		mSelectButton = (Button) findViewById(R.id.btn_select);
		mSelectAllButton = (Button) findViewById(R.id.btn_select_all);
		mCancelAllButton = (Button) findViewById(R.id.btn_select_cancel);
		mSelectAllButton.setOnClickListener(this);
		mCancelAllButton.setOnClickListener(this);

		if (isShow) {
			mSelectButton.setText("取消");
			mCancelAllButton.setVisibility(View.VISIBLE);
			mSelectAllButton.setVisibility(View.VISIBLE);
		} else {
			mSelectButton.setText("点餐");
			mCancelAllButton.setVisibility(View.GONE);
			mSelectAllButton.setVisibility(View.GONE);
		}
		mSelectButton.setOnClickListener(this);
		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"));

			for (int i = 0; i < foods.size(); i++) {
				list.add("data" + " " + i);
			}
			;

		} 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;
		case R.id.btn_select:
			if (isShow) {
				Message message = Message.obtain();
				message.what = 0;
				handler.sendMessage(message);
				mSelectButton.setText("点餐");

			} else {
				Message message = Message.obtain();
				message.what = 1;
				handler.sendMessage(message);
				mSelectButton.setText("取消");
			}
			break;
		case R.id.btn_select_all:
			// 遍历list的长度，将MyAdapter中的map值全部设为true
			for (int i = 0; i < list.size(); i++) {
				MyListViewAdapter.getIsSelected().put(i, true);
			}
			// 数量设为list的长度
			checkNum = list.size();
			// 刷新listview和TextView的显示
			adapter.notifyDataSetChanged();
			break;
		case R.id.btn_select_cancel:
			// 遍历list的长度，将MyAdapter中的map值全部设为true
			for (int i = 0; i < list.size(); i++) {
				MyListViewAdapter.getIsSelected().put(i, false);
			}
			// 数量设为list的长度
			checkNum = list.size();
			// 刷新listview和TextView的显示
			adapter.notifyDataSetChanged();
			break;

		}
	}

	/**
	 * 计算总价格的方法
	 */
	public void myPrice() {
		HashMap 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());

	}
}

动态控制checkbox显示的原理通过初始化Adapter传入参数，具体可以看代码，比较容易理解的。
看一下动态图效果：

样子较为丑陋，海涵

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