仿京东购物车

添加依赖

//加载  图片用的包
    implementation 'com.nostra13.universalimageloader:universal-image-loader:1.9.5'
//Gson
    implementation 'com.google.code.gson:gson:2.6.2'
    // OkHttp
    implementation 'com.squareup.okhttp3:okhttp:3.9.0'
//拦截器
    implementation 'com.squareup.okhttp3:logging-interceptor:3.9.0'//

    //recyclerView的依赖
    compile 'com.android.support:recyclerview-v7:26+'
    //xRecyclerView的依赖
    compile 'com.jcodecraeer:xrecyclerview:1.5.9'

//省去findViewbyid
    implementation 'com.jakewharton:butterknife:8.8.1'
    annotationProcessor 'com.jakewharton:butterknife-compiler:8.8.1'

添加权限

<uses-permission android:name="android.permission.INTERNET"></uses-permission>

android:name=".app.MyApp"

httpconfig

public class HttpConfig {

//京东分类
public static final String CATAGORY_URL = "https://www.zhaoapi.cn/product/getCatagory";
    public static final String PRODUCTCATAGORY_URL = "https://www.zhaoapi.cn/product/getProductCatagory";

    //购物车接口
    public static final String  URL_CART="https://www.zhaoapi.cn/product/getCarts?uid=71";


}

OkHttputils

public class OkHttpUtils {

    public static OkHttpUtils oKhttpUtils;
    private final OkHttpClient okHttpClient;
    private final Handler myhandler;

    private OkHttpUtils() {
        //日志拦截器
        HttpLoggingInterceptor httpLoggingInterceptor = new HttpLoggingInterceptor();
       httpLoggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY);

        //主线程Handler
        myhandler = new Handler(Looper.getMainLooper());
        okHttpClient = new OkHttpClient.Builder()
                .readTimeout(5000, TimeUnit.MILLISECONDS)
                .writeTimeout(5000, TimeUnit.MILLISECONDS)
                .connectTimeout(5000, TimeUnit.MILLISECONDS)
                 .addInterceptor(httpLoggingInterceptor)
                .build();
    }

    public static OkHttpUtils getoKhttpUtils() {
        if (oKhttpUtils == null) {
            synchronized (OkHttpUtils.class) {
                if (oKhttpUtils == null) {
                    return oKhttpUtils = new OkHttpUtils();
                }
            }
        }
        return oKhttpUtils;
    }

    //异步get
    public void doGet(String url, final IOKhttpUtilsCallback ioKhttpUtilsCallback) {
        Request request = new Request.Builder()
                .get()
                .url(url)
                .build();
        Call call = okHttpClient.newCall(request);
        call.enqueue(new Callback() {
            @Override
            public void onFailure(Call call, final IOException e) {
                if (ioKhttpUtilsCallback != null) {
                    //切换到主线程
                    myhandler.post(new Runnable() {
                        @Override
                        public void run() {
                            ioKhttpUtilsCallback.onFailure(e.getMessage());
                        }
                    });
                }
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                if (response != null && response.isSuccessful()) {
                    final String json = response.body().string();
                    if (ioKhttpUtilsCallback != null) {
                        //切换到主线程
                        myhandler.post(new Runnable() {
                            @Override
                            public void run() {
                                ioKhttpUtilsCallback.onResponse(json);
                            }
                        });
                    }

                } else {
                    if (ioKhttpUtilsCallback != null) {
                        //切换到主线程
                        myhandler.post(new Runnable() {
                            @Override
                            public void run() {
                                ioKhttpUtilsCallback.onFailure("网络异常");
                            }
                        });
                    }
                }
            }
        });

    }

    //异步post
    public void doPost(String url, Map<String, String> map, final IOKhttpUtilsCallback ioKhttpUtilsCallback) {
        FormBody.Builder builder = new FormBody.Builder();
        for (Map.Entry<String, String> entry : map.entrySet()) {
            builder.add(entry.getKey(), entry.getValue());
        }
        FormBody formBody = builder.build();
        Request request = new Request.Builder()
                .post(formBody)
                .url(url)
                .build();
        Call call = okHttpClient.newCall(request);
        call.enqueue(new Callback() {
            @Override
            public void onFailure(Call call, final IOException e) {
                if (ioKhttpUtilsCallback != null) {
                    //切换到主线程
                    myhandler.post(new Runnable() {
                        @Override
                        public void run() {
                            ioKhttpUtilsCallback.onFailure(e.getMessage());
                        }
                    });
                }
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                if (response != null && response.isSuccessful()) {
                    final String json = response.body().string();
                    if (ioKhttpUtilsCallback != null) {
                        //切换到主线程
                        myhandler.post(new Runnable() {
                            @Override
                            public void run() {
                                ioKhttpUtilsCallback.onResponse(json);
                            }
                        });
                    }

                } else {
                    if (ioKhttpUtilsCallback != null) {
                        //切换到主线程
                        myhandler.post(new Runnable() {
                            @Override
                            public void run() {
                                ioKhttpUtilsCallback.onFailure("网络异常");
                            }
                        });
                    }
                }
            }
        });
    }

    //接口回调
    public interface IOKhttpUtilsCallback {
        void onFailure(String error);

        void onResponse(String json);
    }

}

activity_cart  主布局

<?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">


    <ExpandableListView
        android:id="@+id/cart_expand"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginBottom="50dp"></ExpandableListView>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="60sp"
        android:layout_alignParentBottom="true">

        <CheckBox
            android:id="@+id/quanxuan"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="全选" />

        <TextView
            android:id="@+id/he"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="20dp"
            android:layout_weight="1"
            android:text="合计:￥0.0" />

        <Button
            android:id="@+id/btn_buy"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="去结算()" />


    </LinearLayout>


</RelativeLayout>

父级xml   cart_parent

<?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="60sp"
    android:layout_gravity="center_vertical"
    >


    <CheckBox
        android:id="@+id/seller_cb"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"

        />


    <TextView
        android:id="@+id/seller_name_tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="20dp"
        android:text="文字"
        />


</LinearLayout>

子级xml  cart_child

<?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="120dp"
    android:gravity="center_vertical"

    >

    <CheckBox
        android:id="@+id/child_cb"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <ImageView
        android:id="@+id/product_img"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:layout_marginLeft="20dp"
        android:src="@mipmap/ic_launcher" />


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <TextView
            android:id="@+id/product_title_name_tv"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="商品标题" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">

            <TextView
                android:id="@+id/child_price"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="￥0.0" />

        </LinearLayout>

        <com.example.moni.mvp.cart.view.MyAddSub
            android:id="@+id/my_sub_add"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="15dp"></com.example.moni.mvp.cart.view.MyAddSub>
    </LinearLayout>
</LinearLayout>

加减号xml  my_sub_add

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="60sp"
    android:layout_height="30dp"
    android:layout_gravity="center_vertical"
    android:gravity="center_vertical"
    android:layout_marginLeft="15dp"
    >


    <TextView
        android:id="@+id/jian"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="-"
        android:background="#fff"
        android:gravity="center"
        android:layout_weight="1"
        />
    <TextView
        android:id="@+id/product_num"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="1"
        android:layout_weight="1"
        android:background="#fff"
        android:gravity="center"
        />

    <TextView
        android:id="@+id/jia"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:background="#fff"
        android:text="+"
        />
</LinearLayout>

model层   cartmodel

public class CartModel {

    public void getCart(final onCallBack onCallBack) {
        String url = HttpConfig.URL_CART;
        OkHttpUtils.getoKhttpUtils().doGet(url, new OkHttpUtils.IOKhttpUtilsCallback() {
            @Override
            public void onFailure(String error) {
                if (onCallBack != null) {
                    onCallBack.onFaild("错了");
                }
            }

            @Override
            public void onResponse(String json) {
                Gson gson = new Gson();
                CartBean cartBean = gson.fromJson(json, CartBean.class);
                String code = cartBean.getCode();
                if ("0".equalsIgnoreCase(code)) {
                    if (onCallBack != null) {
                        onCallBack.onSuccess(cartBean);
                    }
                }
            }



        });

    }

    public interface onCallBack {
        void onSuccess(CartBean cartBean);

        void onFaild(String error);
    }
}

presenter层     cartpresenter

public class CartPresenter extends BasePresenter<CartView>{

    private CartModel cartModel;

    public CartPresenter(CartView view) {
        super(view);
    }

    @Override
    protected void initmodel() {
        cartModel = new CartModel();
    }
    public void doCart() {
        cartModel.getCart(new CartModel.onCallBack() {
            @Override
            public void onSuccess(CartBean cartBean) {
                if (view != null) {
                    view.onSuccess(cartBean);
                }
            }

            @Override
            public void onFaild(String error) {
                if (view != null) {
                    view.onFaild(error);
                }
            }
        });
    }

}

view层   cartView

public interface CartView extends IView {

    void onSuccess(CartBean cartBean);

    void onFaild(String error);

}
加载加减号的类   mysubadd

public class MyAddSub extends LinearLayout{

    @BindView(R.id.jian)
    TextView jian;
    @BindView(R.id.product_num)
    TextView productNum;
    @BindView(R.id.jia)
    TextView jia;
    int number = 1;

    public MyAddSub(Context context) {
        this(context, null);
    }

    public MyAddSub(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        View view = inflate(context, R.layout.my_sub_add, this);

        //初始化
        ButterKnife.bind(view);
    }


    @OnClick({R.id.jian, R.id.product_num, R.id.jia})
    public void onViewClicked(View view) {
        switch (view.getId()) {
            case R.id.jian:
                if (number > 1) {
                    --number;
                    productNum.setText(number + "");
                    if (onNumberChangeListener != null) {
                        onNumberChangeListener.onSubNumberChange(number);
                    }
                } else {
                    Toast.makeText(getContext(), "数量不能小于1", Toast.LENGTH_SHORT).show();
                }
                break;

            case R.id.jia:
                ++number;
                productNum.setText(number + "");
                if (onNumberChangeListener != null) {
                    onNumberChangeListener.onAddNumberChange(number);
                }
                break;
        }
    }

    public int getNumber() {
        return number;
    }

    public void setNumber(int number) {
        this.number = number;
        productNum.setText(number + "");
    }


    private onNumberChangeListener onNumberChangeListener;

    public void setOnNumberChangeListener(MyAddSub.onNumberChangeListener onNumberChangeListener) {
        this.onNumberChangeListener = onNumberChangeListener;
    }

    public interface onNumberChangeListener {
        void onAddNumberChange(int product_num);
        void onSubNumberChange(int product_num);
    }

}

购物车的适配器  ExpandViewAdapter

public class ExpandViewAdapter extends BaseExpandableListAdapter {

    private List<CartBean.DataBean> seller;
    private static final String TAG = "适配器********";

    public ExpandViewAdapter(List<CartBean.DataBean> seller) {
        this.seller = seller;
    }

    @Override
    public int getGroupCount() {
        return seller == null ? 0 : seller.size();
    }

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

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

    @Override
    public Object getChild(int groupPosition, int childPosition) {
        return null;
    }

    @Override
    public long getGroupId(int groupPosition) {
        return 0;
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return 0;
    }

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

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

        CartBean.DataBean dataBean = seller.get(groupPosition);
        ParentHolder parentHolder;
        if (convertView == null) {
            convertView = View.inflate(parent.getContext(), R.layout.cart_parent, null);
            parentHolder = new ParentHolder(convertView);
            convertView.setTag(parentHolder);
        } else {
            parentHolder = (ParentHolder) convertView.getTag();
        }
        //赋值商家名称
        Log.d(TAG, "getGroupView: "+dataBean.getSellerName());
        parentHolder.sellerNameTv.setText(dataBean.getSellerName());
        boolean b = productStatus(groupPosition);
        parentHolder.sellerCb.setChecked(b);
        parentHolder.sellerCb.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (onCartListChangeListener != null) {
                    onCartListChangeListener.SellerCheckChange(groupPosition);
                }
            }
        });
        return convertView;
    }
    @SuppressLint("SetTextI18n")
    @Override
    public View getChildView(final int groupPosition, final int childPosition, boolean isLastChild, View convertView, final ViewGroup parent) {
        CartBean.DataBean.ListBean listBean = seller.get(groupPosition).getList().get(childPosition);
        ChildHolder childHolder;
        if (convertView == null) {
            convertView = View.inflate(parent.getContext(), R.layout.cart_child, null);
            childHolder = new ChildHolder(convertView);
            convertView.setTag(childHolder);
        } else {
            childHolder = (ChildHolder) convertView.getTag();
        }
        //赋值子类名称
        childHolder.productTitleNameTv.setText(listBean.getTitle());
        childHolder.childPrice.setText(listBean.getPrice() + "");
        String[] pic = listBean.getImages().split("\\|");
        ImageLoader.getInstance().displayImage(pic[0], childHolder.productImg, MyApp.getOptions());
        boolean flag = listBean.getSelected() == 1 ? true : false;
        childHolder.childCb.setChecked(flag);
        ;
        childHolder.childCb.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (onCartListChangeListener != null) {
                    onCartListChangeListener.onProductCheckedChange(groupPosition, childPosition);
                    Toast.makeText(parent.getContext(), "kkkkk", Toast.LENGTH_SHORT).show();
                }
            }
        });


        childHolder.mySubAdd.setNumber(listBean.getNum());
        childHolder.mySubAdd.setOnNumberChangeListener(new MyAddSub.onNumberChangeListener() {
            @Override
            public void onAddNumberChange(int product_num) {
                if (onCartListChangeListener != null) {
                    onCartListChangeListener.onProductNumberChange(groupPosition, childPosition, product_num);
                }
            }
            @Override
            public void onSubNumberChange(int product_num) {
                if (onCartListChangeListener != null) {
                    onCartListChangeListener.onProductNumberChange(groupPosition, childPosition, product_num);
                }
            }
        });

        return convertView;
    }

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

    //关于商家按钮
    public boolean productStatus(int groupPosition) {

        List<CartBean.DataBean.ListBean> list = seller.get(groupPosition).getList();
        for (CartBean.DataBean.ListBean listBean : list) {
            if (listBean.getSelected() == 0) {
                return false;
            }
        }
        return true;
    }

    //子类按钮跟着改变
    public void noProductStatus(int groupPosition, boolean b) {

        List<CartBean.DataBean.ListBean> list = seller.get(groupPosition).getList();
        for (int i = 0; i < list.size(); i++) {
            list.get(i).setSelected(b ? 1 : 0);
        }
    }

    //判断所有商品是否选中
    public boolean isAllProductSelected() {

        for (int i = 0; i < seller.size(); i++) {
            List<CartBean.DataBean.ListBean> list = seller.get(i).getList();
            for (int j = 0; j < list.size(); j++) {
                if (list.get(j).getSelected() == 0) {
                    return false;
                }
            }
        }
        return true;
    }

    //关于底部全选按钮
    public void changeAllProductStatus(boolean selected) {

        for (int i = 0; i < seller.size(); i++) {
            List<CartBean.DataBean.ListBean> list = seller.get(i).getList();
            for (int j = 0; j < list.size(); j++) {
                list.get(j).setSelected(selected ? 1 : 0);
            }
        }
    }

    //关于子类按钮
    public void changeCurrentProductStatus(int groupPosition, int childPosition) {

        List<CartBean.DataBean.ListBean> list = seller.get(groupPosition).getList();
        CartBean.DataBean.ListBean listBean = list.get(childPosition);
        listBean.setSelected(listBean.getSelected() == 0 ? 1 : 0);

    }

    //总价格
    public float calcuteTotalPrice() {
        float totlaPrice = 0;
        for (int i = 0; i < seller.size(); i++) {
            List<CartBean.DataBean.ListBean> list = seller.get(i).getList();
            for (int j = 0; j < list.size(); j++) {
                if (list.get(j).getSelected() == 1) {
                    float price = list.get(j).getPrice();
                    int num = list.get(j).getNum();
                    totlaPrice += num * price;
                }
            }
        }
        return totlaPrice;
    }

    //总数量
    public int cacuteTotalNum() {
        int totalNum = 0;
        for (int i = 0; i < seller.size(); i++) {
            List<CartBean.DataBean.ListBean> list = seller.get(i).getList();
            for (int j = 0; j < list.size(); j++) {
                if (list.get(j).getSelected() == 1) {
                    int num = list.get(j).getNum();
                    totalNum += num;
                }

            }
        }
        return totalNum;
    }

    //设置加减按钮
    public void changeCurrentNumberProduct(int groupPosition, int childPosition, int number) {
        List<CartBean.DataBean.ListBean> list = seller.get(groupPosition).getList();

        CartBean.DataBean.ListBean listBean = list.get(childPosition);

        listBean.setNum(number);
    }

    //总价格
    //父类
    static class ParentHolder {
        @BindView(R.id.seller_cb)
        CheckBox sellerCb;
        @BindView(R.id.seller_name_tv)
        TextView sellerNameTv;

        ParentHolder(View view) {
            ButterKnife.bind(this, view);
        }
    }
    //子类
    onCartListChangeListener onCartListChangeListener;

    public void setOnCartListChangeListener(ExpandViewAdapter.onCartListChangeListener onCartListChangeListener) {
        this.onCartListChangeListener = onCartListChangeListener;
    }

    //接口回调
    public interface onCartListChangeListener {
        void SellerCheckChange(int groupPosition);

        void onProductCheckedChange(int groupPosition, int childPosition);

        void onProductNumberChange(int groupPosition, int childPosition, int number);
    }

    static class ChildHolder {
        @BindView(R.id.child_cb)
        CheckBox childCb;
        @BindView(R.id.product_img)
        ImageView productImg;
        @BindView(R.id.product_title_name_tv)
        TextView productTitleNameTv;
        @BindView(R.id.child_price)
        TextView childPrice;
        @BindView(R.id.my_sub_add)
        MyAddSub mySubAdd;

        ChildHolder(View view) {
            ButterKnife.bind(this, view);
        }
    }
}

购物车的fragment

public class CartFragment extends BaseFragment<CartPresenter> implements CartView,View.OnClickListener {

    private CheckBox quanxuan;
    private ExpandableListView expandableListView;
    private Button btn_buy;
    private TextView he;
    private ExpandViewAdapter adapter;

    @Override
    public void onClick(View v) {
        //底部全选按钮
        boolean allProductSelected = adapter.isAllProductSelected();
        adapter.changeAllProductStatus(!allProductSelected);
        //刷新适配器
        adapter.notifyDataSetChanged();
        reFreshSelectedAndToTalPriceAndTotalAllNumber();
    }

    @Override
    public Context context() {
        return getActivity();
    }

    @Override
    public void onSuccess(CartBean cartBean) {
        List<CartBean.DataBean> data = cartBean.getData();
        //创建适配器
        adapter = new ExpandViewAdapter(data);
        expandableListView.setAdapter(adapter);

        adapter.setOnCartListChangeListener(new ExpandViewAdapter.onCartListChangeListener() {
            @Override
            public void SellerCheckChange(int groupPosition) {
                //设置商家
                boolean b = adapter.productStatus(groupPosition);
                //子类按钮跟着改变
                adapter.noProductStatus(groupPosition, !b);
                //刷新适配器
                adapter.notifyDataSetChanged();
                reFreshSelectedAndToTalPriceAndTotalAllNumber();
            }

            @Override
            public void onProductCheckedChange(int groupPosition, int childPosition) {

                adapter.changeCurrentProductStatus(groupPosition, childPosition);
                //刷新适配器
                adapter.notifyDataSetChanged();
                reFreshSelectedAndToTalPriceAndTotalAllNumber();
            }

            @Override
            public void onProductNumberChange(int groupPosition, int childPosition, int number) {
                //设置加减按钮
                adapter.changeCurrentNumberProduct(groupPosition, childPosition, number);
                //刷新适配器
                adapter.notifyDataSetChanged();
                reFreshSelectedAndToTalPriceAndTotalAllNumber();
            }
        });
        //展开二级列表
        for (int i = 0; i < data.size(); i++) {
            expandableListView.expandGroup(i);
        }
        reFreshSelectedAndToTalPriceAndTotalAllNumber();

    }

    @Override
    public void onFaild(String error) {

    }

    @Override
    protected void initViews(View view) {
        //获取id
        quanxuan = view.findViewById(R.id.quanxuan);
        expandableListView = view.findViewById(R.id.cart_expand);
        btn_buy = view.findViewById(R.id.btn_buy);
        he = view.findViewById(R.id.he);
        quanxuan.setOnClickListener(this);
    }

    @Override
    protected void initData() {
       presenter.doCart();
    }

    @Override
    protected void initListener() {

    }

    @Override
    protected CartPresenter providePresenter() {
        return new CartPresenter(this);
    }

    @Override
    protected int privideLayoutId() {
        return R.layout.activity_cart;
    }
    public void reFreshSelectedAndToTalPriceAndTotalAllNumber() {
        //判断是否全部选中
        boolean allProductSelected = adapter.isAllProductSelected();
        quanxuan.setChecked(allProductSelected);
        //刷新适配器
        //adapter.notifyDataSetChanged();
//        reFreshSelectedAndToTalPriceAndTotalAllNumber();
        //设置总价格
        float totalPrice = adapter.calcuteTotalPrice();
        he.setText("总价格(" + totalPrice + ")");
        //总数量
        int totalNum = adapter.cacuteTotalNum();
        btn_buy.setText("总数量" + totalNum);
    }

}