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:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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="match_parent"
android:layout_height="match_parent"
android:layout_above="@+id/ll_btns"
>
</ListView>
<LinearLayout
android:id="@+id/ll_btns"
android:layout_width="match_parent"
android:layout_height="58dp"
android:layout_alignParentBottom="true"
android:orientation="horizontal" >
<Button
android:id="@+id/btn_commit"
android:layout_width="wrap_content"
android:layout_height="58dp"
android:text="确定" />
<Button
android:id="@+id/btn_select"
android:layout_width="wrap_content"
android:layout_height="58dp"
android:text="点餐" />
<Button
android:id="@+id/btn_select_all"
android:layout_width="wrap_content"
android:layout_height="58dp"
android:text="全选" />
<Button
android:id="@+id/btn_select_cancel"
android:layout_width="wrap_content"
android:layout_height="58dp"
android:text="反选" />
</LinearLayout>
</RelativeLayout>
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.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<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;
private Boolean isShow=false;
// 构造器
public MyListViewAdapter(ArrayList<Food> list, Context context,Boolean isShow) {
this.context = context;
this.foodlist = list;
inflater = LayoutInflater.from(context);
isSelected = new HashMap<Integer, Boolean>();
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<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.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<Food> foods = new ArrayList<Food>();
private MyListViewAdapter adapter;
private CheckBox checkBox;
private int checkNum; // 记录选中的条目数量
private ArrayList<String> 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<String>();
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<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());
}
}
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
喜欢的朋友可以关注我和我的公众号，谢谢！
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时间： 2024-10-05 20:28:42