购物车+逻辑

效果

1.首先搭mvp框架,然后在其中接收数据,并解析:

@Override
    public void showData(String string) {
        Gson gson = new Gson();
        HomeBean homeBean = gson.fromJson(string, HomeBean.class);
        //外层商家条目的数据源
        data = homeBean.getData();
        //删除第一个商家(空的)
        data.remove(0);
        LinearLayoutManager layoutManager = new LinearLayoutManager(getActivity(), LinearLayoutManager.VERTICAL, false);
        businessRcl.setLayoutManager(layoutManager);
        badapter = new MybusinessAdapter(R.layout.presant, data);
        businessRcl.setAdapter(badapter);
        //避免焦点抢占
        allCb.setOnCheckedChangeListener(null);
        //全选的点击监听
        allCb.setOnClickListener(this);
        
		badapter.setOnBusinessItemClickLisenter(new MybusinessAdapter.OnBusinessItemClickLisenter() {
        @Override
        public void onCallBack() {
            boolean result=true;
            for (int i = 0; i < data.size(); i++) {
            	//外层选中状态
                result=result & data.get(i).isBusinesscheck();
                for (int j = 0; j < data.get(i).getList().size(); j++) {
                	//里层选中状态
                    result=result & data.get(i).getList().get(j).isGoodscheck();
                }
            }
            allCb.setChecked(result);
            //计算总价
            zongjia();
        }
    });
	private void zongjia() {
		//对总价进行计算,在Bean包中定义一个private double DefalutNumber=1;加getset方法
    	double totalCount=0;
    	for (int i = 0; i < data.size(); i++) {
    	//内层条目
        	for (int j = 0; j < data.get(i).getList().size(); j++) {
        	//判断内层条目是否勾选
            	if (data.get(i).getList().get(j).isGoodscheck()==true){
                	double price = data.get(i).getList().get(j).getPrice();
                	//获取商品数据*商品价格
                	double defalutNumber = data.get(i).getList().get(j).getDefalutNumber();
                	double goodsPrice=price * defalutNumber;
                	totalCount=totalCount+goodsPrice;
            	}
        	}
    	}
    	allZj.setText("总价是:"+String.valueOf(totalCount));
	}

		//全选监听的点击,要在内外层商家的Bean中添加全选的方法,setget方法
        @Override
		public void onClick(View v) {
		//全选逻辑的处理
  		  for (int i = 0; i < data.size(); i++) {
  		  //首先让外层的商家条目全部选中
       		 data.get(i).setBusinesscheck(allCb.isChecked());
       		 //然后让里层的商品条目全部选中
       			 for (int j = 0; j < data.get(i).getList().size(); j++) {
            		data.get(i).getList().get(j).setGoodscheck(allCb.isChecked());
        }
    }
    //适配器刷新
    badapter.notifyDataSetChanged();
    //计算总价
    zongjia();
  }
 }

2.商家适配器

	//接口回调
	OnBusinessItemClickLisenter onBusinessItemClickLisenter;
	public void setOnBusinessItemClickLisenter(OnBusinessItemClickLisenter onBusinessItemClickLisenter) {
    this.onBusinessItemClickLisenter = onBusinessItemClickLisenter;
}
	public interface OnBusinessItemClickLisenter{
    public void onCallBack();
}
	//设置商家名称
	helper.setText(R.id.business_name,item.getSellerName());
	//外层商家条目的数据源
    final List<HomeBean.DataBean.ListBean> goods_data = item.getList();
    RecyclerView goodsrly = helper.getView(R.id.goods_rly);
    LinearLayoutManager layoutManager=new LinearLayoutManager(mContext,LinearLayoutManager.VERTICAL,false);
    goodsrly.setLayoutManager(layoutManager);
    final MygoodsAdapter gadapter =new MygoodsAdapter(R.layout.goods, goods_data);
    //设置子条目适配器
    goodsrly.setAdapter(gadapter);
	//避免焦点抢占
    final CheckBox businesscb = helper.getView(R.id.business_cb);
    businesscb.setOnCheckedChangeListener(null);
    //获取商家条目是否选中状态
    businesscb.setChecked(item.isBusinesscheck());
    //首先处理内部子条目控制外部条目
    gadapter.setOnGoodsItemClickLisenter(new MygoodsAdapter.OnGoodsItemClickLisenter() {
        @Override
        public void onCallBack() {
        	//遍历获取所有子条目，只要有一个未勾选，商品类别也应该是未勾选
            boolean result=true;
            for (int i = 0; i < item.getList().size(); i++) {
                result=result & item.getList().get(i).isGoodscheck();
            }
            businesscb.setChecked(result);
            //刷新适配器
            gadapter.notifyDataSetChanged();
            //把最后的状态进行回传,上面需要写接口回调
            onBusinessItemClickLisenter.onCallBack();
        }
    });
	//然后外层的商品类别条目需要控制里面的商品条目
    businesscb.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
        	//获取商品类别勾选状态
            //外层商品类别条目获取的关键：cb_business.isChecked()
            for (int i = 0; i < item.getList().size(); i++) {
                item.getList().get(i).setGoodscheck(businesscb.isChecked());
            }
            item.setBusinesscheck(businesscb.isChecked());
            notifyDataSetChanged();
            //把最后的状态进行回传
            onBusinessItemClickLisenter.onCallBack();
        }
    });
   }
  }

3.商品适配器

//接口回调
OnGoodsItemClickLisenter onGoodsItemClickLisenter;
public void setOnGoodsItemClickLisenter(OnGoodsItemClickLisenter onGoodsItemClickLisenter) {
    this.onGoodsItemClickLisenter = onGoodsItemClickLisenter;
}
public interface OnGoodsItemClickLisenter{
    public void onCallBack();
}

	//设置商品名称
	helper.setText(R.id.goods_name,item.getTitle());
	//设置商品图片
    helper.setText(R.id.goods_jq,item.getPrice()+"");
    String images = item.getImages();
    //截取图片
    String[] split = images.split("\\|");
    Glide.with(mContext).load(split[0]).into((ImageView) helper.getView(R.id.goods_img));
	//避免焦点抢占
    final CheckBox goodscb = helper.getView(R.id.goods_cb);
    goodscb.setOnCheckedChangeListener(null);
    goodscb.setChecked(item.isGoodscheck());
	//以接口的方式把状态回传给外层
    goodscb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
        	//Bean对象状态进行更新完毕
            item.setGoodscheck(isChecked);
            onGoodsItemClickLisenter.onCallBack();
        }
    });
	//加减器
    classcalculator jjview = helper.getView(R.id.class_jjview);
    jjview.setOnCalCulatorLisenter(new classcalculator.OnCalCulatorLisenter() {
        @Override
        public void onDecrese(int number) {
        	//对新增的字段进行改动
            item.setDefalutNumber(number);
            onGoodsItemClickLisenter.onCallBack();
        }

        @Override
        public void onAdd(int number) {
        	//对新增的字段进行改动
            item.setDefalutNumber(number);
            onGoodsItemClickLisenter.onCallBack();
        }
    });
 }
}

4.加减类

public classcalculator(Context context, AttributeSet attrs) {
    super(context, attrs);
    //填充的条目布局
    View inflate = View.inflate(context, R.layout.class_calculator, null);
    buttonadd = inflate.findViewById(R.id.button_add);
    buttonreduce = inflate.findViewById(R.id.button_reduce);
    textnumber = inflate.findViewById(R.id.text_number);
    addView(inflate);
    buttonadd.setOnClickListener(this);
    buttonreduce.setOnClickListener(this);
}
@Override
public void onClick(View v) {
    String numberString = textnumber.getText().toString();
    int number = Integer.parseInt(numberString);
    switch (v.getId()){
        case R.id.button_add:
            number=number+1;
            textnumber.setText(String.valueOf(number));
            //接口回调回传数字
            onCalCulatorLisenter.onAdd(number);
            break;
        case R.id.button_reduce:
            number=number - 1;
            if (number<0){
                number=0;
                //最小数量为0
                textnumber.setText(String.valueOf(number));
            }
            textnumber.setText(String.valueOf(number));
            //接口回调回传数字
            onCalCulatorLisenter.onDecrese(number);
            break;
    }
}
//接口回调
OnCalCulatorLisenter onCalCulatorLisenter;
public void setOnCalCulatorLisenter(OnCalCulatorLisenter onCalCulatorLisenter) {
    this.onCalCulatorLisenter = onCalCulatorLisenter;
}
public interface OnCalCulatorLisenter{
    //减少
    public void onDecrese(int number);
    //增加
    public void onAdd(int number);
}

5.主页布局

	<?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.support.v7.widget.RecyclerView
            android:id="@+id/business_rcl"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_above="@+id/ll">
        </android.support.v7.widget.RecyclerView>
    <RelativeLayout
        android:id="@+id/ll"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:layout_alignParentBottom="true"
        >
        <CheckBox
            android:id="@+id/all_cb"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:text="全选" />

        <TextView
            android:id="@+id/all_zj"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="185dp"
            android:layout_centerVertical="true"
            android:padding="10dp"
            android:text="总计:0" />

        <Button
            android:id="@+id/all_js"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="right"
            android:layout_alignParentRight="true"
            android:layout_centerVertical="true"
            android:background="@drawable/mygouwucheline"
            android:text="结算" />
    </RelativeLayout>
</RelativeLayout>

6.商家布局

	<?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="wrap_content"
    android:padding="15dp"
    android:background="@drawable/homeshop"
    android:layout_margin="5dp"
    android:layout_marginTop="20dp"
    android:paddingTop="20dp"
    android:orientation="vertical">
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal">
    <CheckBox
        android:id="@+id/business_cb"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <TextView
        android:id="@+id/business_name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="lalala"/>
</LinearLayout>
    <android.support.v7.widget.RecyclerView
        android:id="@+id/goods_rly"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"></android.support.v7.widget.RecyclerView>

</LinearLayout>

7.商品布局

	<?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="wrap_content"
    android:padding="15dp"
    android:background="@drawable/homeshop"
    android:layout_margin="5dp"
    android:orientation="vertical">
<LinearLayout
    android:layout_marginLeft="@dimen/dp_10"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal">
    <CheckBox
        android:id="@+id/goods_cb"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical"
        />
    <ImageView
        android:id="@+id/goods_img"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:layout_marginLeft="@dimen/dp_10"/>
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="@dimen/dp_10"
        android:orientation="vertical">

        <TextView
            android:id="@+id/goods_name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:maxLines="2"
            android:ellipsize="end"
            android:text="lalala"/>
        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal">
        <TextView
            android:id="@+id/goods_jq"
            android:layout_marginTop="15dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textColor="#ba0404"
            android:textSize="15dp"
            android:text="lalala"/>
        <zhoukao.zjq.com.shopping.ui.classcalculator
            android:id="@+id/class_jjview"
            android:layout_marginTop="@dimen/dp_10"
            android:layout_marginLeft="18dp"
            android:layout_width="match_parent"
            android:layout_height="30dp">
        </zhoukao.zjq.com.shopping.ui.classcalculator>
        </LinearLayout>
    </LinearLayout>
</LinearLayout>

</LinearLayout>

8.加减布局

	<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:orientation="horizontal"
    android:layout_height="wrap_content">
    <Button
        android:id="@+id/button_reduce"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:background="@drawable/reduce"/>

    <TextView
        android:id="@+id/text_number"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:gravity="center"
        android:inputType="number"
        android:text="1" />
    <Button
        android:id="@+id/button_add"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:background="@drawable/add"/>
</LinearLayout>

以上就是购物车的逻辑了