购物车列表视图实现-优快云博客

本文链接：https://blog.youkuaiyun.com/weixin_43717447/article/details/85108498

本文详细介绍了一种购物车功能的实现方式，包括使用ExpandableListView展示不同商家的商品列表，自定义适配器处理复杂的数据结构，以及通过CheckBox实现商品的多级选择和总价计算。

在这里插入图片描述
条目布局
cart2_group_item

<?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="horizontal">

<CheckBox
    android:id="@+id/checkBox"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_weight="1"
    android:focusable="false"
    android:text="CheckBox" />
</LinearLayout>

cart_item

<?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="wrap_content"
android:padding="10dp"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:background="@drawable/search_edit_bg"
android:orientation="horizontal">

<CheckBox
    android:id="@+id/cart_goods_check"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_centerVertical="true"/>
<ImageView
    android:id="@+id/image"
    android:layout_width="100dp"
    android:layout_height="wrap_content"
    android:adjustViewBounds="true"
    android:minHeight="50dp"
    android:layout_toRightOf="@+id/cart_goods_check"
    android:src="@mipmap/ic_launcher"/>

<TextView
    android:id="@+id/text"
    android:layout_toRightOf="@+id/image"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="10dp"
    android:text="aa"
    android:padding="10dp"/>
<TextView
    android:id="@+id/text_price"
    android:layout_toRightOf="@+id/image"
    android:layout_below="@+id/text"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="10dp"
    android:text="价格"
    android:padding="10dp"/>

<com.baidu.mooktesk1.util.view.AddSubLayout
    android:id="@+id/add_sub_layout"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_alignParentBottom="true"
    android:layout_marginRight="20dp"
    android:layout_marginBottom="20dp">

</com.baidu.mooktesk1.util.view.AddSubLayout>

</RelativeLayout>

适配器
CartAdapter2

public class CartAdapter2 extends BaseExpandableListAdapter {

private List<Shop> mList = new ArrayList<>();

private TotalPriceListener totalPriceListener;

public CartAdapter2(){
}

public void setTotalPriceListener(TotalPriceListener totalPriceListener) {
    this.totalPriceListener = totalPriceListener;
}

@Override
public int getGroupCount() {
    return mList.size();
}

@Override
public int getChildrenCount(int groupPosition) {
    return mList.get(groupPosition).getList().size();
}

@Override
public Object getGroup(int groupPosition) {
    return mList.get(groupPosition);
}

@Override
public Object getChild(int groupPosition, int childPosition) {
    return mList.get(groupPosition).getList().get(childPosition);
}

@Override
public long getGroupId(int groupPosition) {
    return groupPosition;
}

@Override
public long getChildId(int groupPosition, int childPosition) {
    return childPosition;
}

@Override
public boolean hasStableIds() {
    return false;
}

@Override
public View getGroupView(final int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {

    GroupHodler holder;

    if (convertView == null) {
        convertView = View.inflate(parent.getContext(), R.layout.cart2_group_item, null);
        holder = new GroupHodler();
        holder.checkBox = convertView.findViewById(R.id.checkBox);
        convertView.setTag(holder);
    } else {
        holder = (GroupHodler) convertView.getTag();
    }
    final Shop shop = mList.get(groupPosition);

    holder.checkBox.setText(shop.getSellerName());
    holder.checkBox.setChecked(shop.isCheck());//设置商铺选中状态
    holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            shop.setCheck(isChecked);//数据更新
            List<Goods> goodsList = mList.get(groupPosition).getList();//得到商品信息
            for (int i = 0; i < goodsList.size(); i++) {//商品信息循环赋值
                goodsList.get(i).setSelected(isChecked?1:0);//商铺选中则商品必须选中
            }
            notifyDataSetChanged();

            //计算价格
            calculatePrice();
        }
    });

    return convertView;
}

@Override
public View getChildView(int groupPosition, final int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
    MyHolder holder;

    if (convertView == null) {
        convertView = View.inflate(parent.getContext(), R.layout.cart_item, null);
        holder = new MyHolder();
        holder.text = convertView.findViewById(R.id.text);
        holder.price = convertView.findViewById(R.id.text_price);
        holder.image = convertView.findViewById(R.id.image);
        holder.addSub = convertView.findViewById(R.id.add_sub_layout);
        holder.check = convertView.findViewById(R.id.cart_goods_check);
        convertView.setTag(holder);
    } else {
        holder = (MyHolder) convertView.getTag();
    }
    final Goods goods = mList.get(groupPosition).getList().get(childPosition);
    holder.text.setText(goods.getTitle());
    holder.price.setText("单价："+goods.getPrice());//单价
    //点击选中，计算价格
    holder.check.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            goods.setSelected(isChecked?1:0);
            calculatePrice();//计算价格
        }
    });

    if (goods.getSelected()==0){
        holder.check.setChecked(false);
    }else{
        holder.check.setChecked(true);
    }

    String imageurl = "https" + goods.getImages().split("https")[1];
    Log.i("dt", "imageUrl: " + imageurl);
    imageurl = imageurl.substring(0, imageurl.lastIndexOf(".jpg") + ".jpg".length());
    Glide.with(DTApplication.getInstance()).load(imageurl).into(holder.image);//加载图片

    holder.addSub.setCount(goods.getNum());//设置商品数量
    holder.addSub.setAddSubListener(new AddSubLayout.AddSubListener() {
        @Override
        public void addSub(int count) {
            goods.setNum(count);
            calculatePrice();//计算价格
        }
    });
    return convertView;
}

/**
 * @author dingtao
 * @date 2018/12/18 7:33 PM
 * 全部选中或者取消
 */
public void checkAll(boolean isCheck){
    for (int i = 0; i < mList.size(); i++) {//循环的商家
        Shop shop = mList.get(i);
        shop.setCheck(isCheck);
        for (int j = 0; j < shop.getList().size(); j++) {
            Goods goods = shop.getList().get(j);
            goods.setSelected(isCheck?1:0);
        }
    }
    notifyDataSetChanged();
    calculatePrice();
}

/**
 * @author dingtao
 * @date 2018/12/18 7:01 PM
 * 计算总价格
 */
private void calculatePrice(){
    double totalPrice=0;
    for (int i = 0; i < mList.size(); i++) {//循环的商家
        Shop shop = mList.get(i);
        for (int j = 0; j < shop.getList().size(); j++) {
            Goods goods = shop.getList().get(j);
            if (goods.getSelected()==1) {//如果是选中状态
                totalPrice = totalPrice + goods.getNum() * goods.getPrice();
            }
        }
    }
    if (totalPriceListener!=null)
        totalPriceListener.totalPrice(totalPrice);
}

public void addAll(List<Shop> data) {
    if (data != null)
        mList.addAll(data);
}

class MyHolder {
    CheckBox check;
    TextView text;
    TextView price;
    ImageView image;
    AddSubLayout addSub;
}

@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
    return false;
}

class GroupHodler {
    CheckBox checkBox;
}

public interface TotalPriceListener{
    void totalPrice(double totalPrice);
}
}

主页面布局

<?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">

<ExpandableListView
    android:id="@+id/list_cart"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_weight="1">

</ExpandableListView>

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="50dp">

    <CheckBox
        android:id="@+id/check_all"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_marginLeft="10dp"
        android:text="全选" />
    <TextView
        android:id="@+id/goods_sum_price"
        android:layout_toRightOf="@+id/check_all"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="价格："
        android:layout_marginLeft="20dp"
        android:layout_centerVertical="true"/>
</RelativeLayout>
</LinearLayout>

Activity
ShopCartActivity2

public class ShopCartActivity2 extends AppCompatActivity implements
    DataCall<List<Shop>>,CartAdapter2.TotalPriceListener {

private TextView mSumPrice;
private CheckBox mCheckAll;

private ExpandableListView mGoodsList;
private CartAdapter2 mCartAdapter;

private CartPresenter cartPresenter = new CartPresenter(this);

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_cart2);

    mSumPrice = findViewById(R.id.goods_sum_price);
    mCheckAll = findViewById(R.id.check_all);
    mCheckAll.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            mCartAdapter.checkAll(isChecked);
        }
    });
    mGoodsList = findViewById(R.id.list_cart);
    mCartAdapter = new CartAdapter2();
    mGoodsList.setAdapter(mCartAdapter);
    mCartAdapter.setTotalPriceListener(this);//设置总价回调器
    mGoodsList.setGroupIndicator(null);
    //让其group不能被点击
    mGoodsList.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {
        @Override
        public boolean onGroupClick(ExpandableListView parent, View v, int groupPosition, long id) {

            return true;
        }
    });
    cartPresenter.requestData();
}

@Override
public void success(List<Shop> data) {
    mCartAdapter.addAll(data);
    //遍历所有group,将所有项设置成默认展开
    int groupCount = data.size();
    for (int i = 0; i < groupCount; i++) {
        mGoodsList.expandGroup(i);
    }

    mCartAdapter.notifyDataSetChanged();
}

@Override
public void fail(Result result) {
    Toast.makeText(this, result.getCode() + "   " + result.getMsg(), Toast.LENGTH_LONG).show();
}

@Override
public void totalPrice(double totalPrice) {
    mSumPrice.setText(String.valueOf(totalPrice));
}
}

购物车二