购物车的实现(ExpandableListView)

购物车

简单的准备工作

我这里按钮做了两个shape,无需多言,

布局文件
main.xml

car_add_sub_layout.xml

cart2_group_item.xml

cart_item.xml

这里最后一个有自定义类(附上) 主要实现了自定义算法数量的加减运算

public class AddSubLayout extends LinearLayout implements View.OnClickListener {


    private TextView mAddBtn,mSubBtn;
    private TextView mNumText;
    private AddSubListener addSubListener;

    public AddSubLayout(Context context) {
        super(context);
        initView();
    }

    public AddSubLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
        initView();
    }

    public AddSubLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        initView();
    }

    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    public AddSubLayout(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        initView();
    }

    private void initView(){
        //加载layout布局，第三个参数ViewGroup一定写成this
        View view = View.inflate(getContext(),R.layout.car_add_sub_layout,this);

        mAddBtn = view.findViewById(R.id.btn_add);
        mSubBtn = view.findViewById(R.id.btn_sub);
        mNumText = view.findViewById(R.id.text_number);
        mAddBtn.setOnClickListener(this);
        mSubBtn.setOnClickListener(this);

    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        super.onLayout(changed, l, t, r, b);

        int width = r-l;//getWidth();
        int height = b-t;//getHeight();

    }

    @Override
    public void onClick(View v) {
        int number = Integer.parseInt(mNumText.getText().toString());

        switch (v.getId()){
            case R.id.btn_add:
                number++;
                mNumText.setText(number+"");
                break;
            case R.id.btn_sub:
                if (number==0){
                    Toast.makeText(getContext(),"数量不能小于0",Toast.LENGTH_LONG).show();
                    return;
                }
                number--;
                mNumText.setText(number+"");
                break;
        }
        if (addSubListener!=null){
            addSubListener.addSub(number);
        }
    }

    public void setCount(int count) {
        mNumText.setText(count+"");
    }

    public void setAddSubListener(AddSubListener addSubListener) {
        this.addSubListener = addSubListener;
    }

    public interface AddSubListener{
        void addSub(int count);
    }
}

以上是布局
下面:主要代码实现(当然你可以采用本地数据,这里我使用接口里的数据采用mvp模式获取数据)

先复一遍mvp模式(如果是自己写的bean类即可以跳过)

//接口
public interface ShangPinInter {

    void success(T data);

    void fail(Result result);
}
//presenter
public class ShangpinPresenter {
    public ShangPinInter shangPinInter ;

    public ShangpinPresenter(ShangPinInter shangPinInter) {
        this.shangPinInter = shangPinInter;
    }

    @SuppressLint("HandlerLeak")
    Handler handler = new Handler(){
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            Result result = (Result) msg.obj;
            int code = result.getCode();
            if (code  == 0){

                shangPinInter.success(result.getData());
            }else{
                shangPinInter.fail(result);
            }
        }
    };
    public void shangpinShow() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                Result result = Mmodel.shangpinShow();
                Message message = new Message();
                message.obj = result;
                handler.sendMessage(message);
            }
        }).start();
    }
}
       //model
       Gson gson = new Gson();
        Type type = new TypeToken>>() {
        }.getType();
        Result result = gson.fromJson(s4, type);
        return result;

      //Activity
      public class Car extends Fragment implements ShangPinInter> ,CarAdapter2.TotalPriceListener{

}

以上mvp
下面是最重要的适配器以及Activity中回调适配器中的方法(接口回调):

public class Car extends Fragment implements ShangPinInter> ,CarAdapter2.TotalPriceListener{

    ShangpinPresenter shangpinPresenter = new ShangpinPresenter(this);
    private CarAdapter2 carAdapter2;
    private ExpandableListView mGoodsList;
    private CheckBox mCheckAll;
    private TextView mSumPrice;




    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.car,container,false);
        /**
         *全选功能,适配器中的全选方法
         */
        mCheckAll = (CheckBox) view.findViewById(R.id.check_all);
        mCheckAll.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                carAdapter2.checkAll(isChecked);
            }
        });
        /**
         *   页面价格的回显组件
         */
        mSumPrice = (TextView) view.findViewById(R.id.goods_sum_price);
        /**
         * 购物车的适配器
         */
        mGoodsList = (ExpandableListView) view.findViewById(R.id.list_cart);
        carAdapter2 = new CarAdapter2(this);
        mGoodsList.setAdapter(carAdapter2);
        //设置价格总调
        carAdapter2.setTotalPriceListener(this);
        //去掉二级列表的默认箭头
        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;
            }
        });
        //mvp请求数据
        shangpinPresenter.shangpinShow();

        return view;
    }

    //mvp模式成功的反应结果
    @Override
    public void success(List data) {
        //适配器的添加对象的方法
        carAdapter2.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);
        }
        carAdapter2.notifyDataSetChanged();

    }

    //mvp模式失败的反应结果
    @Override
    public void fail(Result result) {

    }

    //适配器中的计算总价(接口回调实现的)...
    @Override
    public void totalPrice(double totalPrice) {
         mSumPrice.setText(String.valueOf(totalPrice));
    }
}

适配器

public class CarAdapter2 extends BaseExpandableListAdapter {
    //构造的商品信息表店家中的子类商品
    private List  mList = new ArrayList();
    //接口回调价格
    private TotalPriceListener totalPriceListener;

    public CarAdapter2(Car car) {
    }
    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;
    }

    //父列表优化
    @Override
    public View getGroupView(final int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
        GroupHodler hodler;
        if (convertView == null){
            convertView = View.inflate(parent.getContext(),R.layout.cart2_group_item,null);
            hodler = new GroupHodler();
            hodler.checkBox = convertView.findViewById(R.id.checkBox);
            convertView.setTag(hodler);
        }else{
            hodler = (GroupHodler)convertView.getTag();
        }
        final Shop shop = mList.get(groupPosition);

        hodler.checkBox.setText(shop.getSellerName());
        hodler.checkBox.setChecked(shop.isCheck());//设置商铺选中状态
        hodler.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                shop.setCheck(isChecked);//数据更新
                List 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;
    }

    //价格计算
    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);
    }

    //子列表优化
    @Override
    public View getChildView(int groupPosition, 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];
        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;
    }

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

  
    
    //接口回调给Activity页面显示价格刷新
    public interface TotalPriceListener{
        void totalPrice(double totalPrice);
    }
    //添加全部对象
    public void addAll(List data) {
        if (data!=null){
            mList.addAll(data);
        }
    }

    /**
     *全部选中功能
     * @param isCheck
     */
    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();
        //刷新价格
        calculatePrice();
    }


    //父框件仅仅包含checkbox
    class GroupHodler {
        CheckBox checkBox;
    }
    //子框件 (一个复选框 ,, 文字 ,, 价格 ,, 图片 ,, 还有自定义一个类) 
    class MyHolder{
        CheckBox check;
        TextView text;
        TextView price;
        ImageView image;
        AddSubLayout addSub;
    }
}

bean类构造
Goods

public class Goods implements Serializable {


//        "bargainPrice": 111.99,
//            "createtime": "2017-10-14T21:39:05",
//            "detailUrl": "https:\/\/item.m.jd.com\/product\/4719303.html?utm_source=androidapp&utm_medium=appshare&utm_campaign=t_335139774&utm_term=QQfriends",
//            "images": "https:\/\/m.360buyimg.com\/n0\/jfs\/t9004\/210\/1160833155\/647627\/ad6be059\/59b4f4e1N9a2b1532.jpg!q70.jpg|https:\/\/m.360buyimg.com\/n0\/jfs\/t7504\/338\/63721388\/491286\/f5957f53\/598e95f1N7f2adb87.jpg!q70.jpg|https:\/\/m.360buyimg.com\/n0\/jfs\/t7441\/10\/64242474\/419246\/adb30a7d\/598e95fbNd989ba0a.jpg!q70.jpg",
//            "itemtype": 1,
//            "pid": 1,
//            "price": 118.0,
//            "pscid": 1,
//            "salenum": 0,
//            "sellerid": 17,
//            "subhead": "每个中秋都不能简单，无论身在何处，你总需要一块饼让生活更圆满，京东月饼让爱更圆满京东自营，闪电配送，更多惊喜，快用手指戳一下",
//            "title": "北京稻香村 稻香村中秋节月饼 老北京月饼礼盒655g"

    private double bargainPrice;
    private String createtime;
    private String detailUrl;
    private String images;
    private int num;
    private int pid;
    private double price;
    private int pscid;
    private int selected;
    private int sellerid;
    private String subhead;
    private String title;
    private int count=1;

    public void setCount(int count) {
        this.count = count;
    }

    public int getCount() {
        return count;
    }

    public double getBargainPrice() {
        return bargainPrice;
    }

    public void setBargainPrice(double bargainPrice) {
        this.bargainPrice = bargainPrice;
    }

    public String getCreatetime() {
        return createtime;
    }

    public void setCreatetime(String createtime) {
        this.createtime = createtime;
    }

    public String getDetailUrl() {
        return detailUrl;
    }

    public void setDetailUrl(String detailUrl) {
        this.detailUrl = detailUrl;
    }

    public String getImages() {
        return images;
    }

    public void setImages(String images) {
        this.images = images;
    }

    public int getNum() {
        return num;
    }

    public void setNum(int num) {
        this.num = num;
    }

    public int getPid() {
        return pid;
    }

    public void setPid(int pid) {
        this.pid = pid;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public int getPscid() {
        return pscid;
    }

    public void setPscid(int pscid) {
        this.pscid = pscid;
    }

    public int getSelected() {
        return selected;
    }

    public void setSelected(int selected) {
        this.selected = selected;
    }

    public int getSellerid() {
        return sellerid;
    }

    public void setSellerid(int sellerid) {
        this.sellerid = sellerid;
    }

    public String getSubhead() {
        return subhead;
    }

    public void setSubhead(String subhead) {
        this.subhead = subhead;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }
}

Result

public class Result {
    int code;
    String msg;
    T data;

    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public T getData() {
        return data;
    }

    public void setData(T data) {
        this.data = data;
    }
}

Shop

public class Shop {
    List list;
    String sellerName;
    String sellerid;
    int textColor = 0xffffffff;
    int background = R.color.grayblack;

    boolean check;


    public void setTextColor(int textColor) {
        this.textColor = textColor;
    }

    public int getTextColor() {
        return textColor;
    }

    public void setBackground(int background) {
        this.background = background;
    }

    public int getBackground() {
        return background;
    }

    public void setCheck(boolean check) {
        this.check = check;
    }

    public boolean isCheck() {
        return check;
    }

    public List getList() {
        return list;
    }

    public void setList(List list) {
        this.list = list;
    }

    public String getSellerName() {
        return sellerName;
    }

    public void setSellerName(String sellerName) {
        this.sellerName = sellerName;
    }

    public String getSellerid() {
        return sellerid;
    }

    public void setSellerid(String sellerid) {
        this.sellerid = sellerid;
    }
}