购物车

购物车

• 如果你要完成购物车,那么你必须掌握以下的技术:expandableListView,接口回调,Java双重for循环,okhttp及封装,组合式自定义控件
• 提示:在敲购物车之前,先测试拷贝过来的OKhttp工具类与组合式自定义控件是否有问题,购物车接口数据是否有问题
• 1.搭建环境(依赖和权限)
• 2.okhttp的封装工具及组合式自定义控件(注意拷贝过来的时候一定要测试一下是否有问题)
• 3.购物车里涉及的布局及控件的初始化
• 4.使用网络的工具类Post请求数据,注意必须是map.put(“uid”,“71”);
• 5.创建Bean,并进行Gson解析
• 6.创建BaseExpandableListAdapter适配器,进行初始化对象,再设置适配器
• 7.为显示二级列表再多写for循环

布局
主布局

RelativeLayout xmlns:android=“http://schemas.android.com/apk/res/android”
android:layout_width=“match_parent”
android:layout_height=“match_parent”>

数量加减布局

LinearLayout xmlns:android=“http://schemas.android.com/apk/res/android”
android:padding=“2dp”
android:layout_marginLeft=“10dp”
android:layout_width=“60dp”
android:layout_height=“30dp”
android:layout_gravity=“center_vertical”
android:background="#99000000"
android:gravity=“center_vertical”>

ExpandableListView父布局

ExpandableListView子布局

LinearLayout xmlns:android=“http://schemas.android.com/apk/res/android”
android:layout_width=“match_parent”
android:layout_height=“120dp”
android:gravity=“center_vertical”>

MainActivity
package com.www.shopcar;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.ExpandableListView;
import android.widget.TextView;
import android.widget.Toast;

import com.google.gson.Gson;

import java.util.HashMap;
import java.util.List;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

private ExpandableListView expand_menu;
private CheckBox cb_cart_all_select;
private TextView tv_cart_total_price;
private Button btn_cart_pay;
String url = "http://www.zhaoapi.cn/product/getCarts";
private ShopCarAdapter adapter;

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

    initData();

}

private void initData() {
    HashMap map = new HashMap<>();
    map.put("uid","71");
    OkHttpUtils.getInstance().doPost(url, map, new OkHttpUtils.OkCallback() {
        @Override
        public void onFile(Exception e) {
        }
        @Override
        public void onSuccess(String json) {

            ShopInfo shopInfo = new Gson().fromJson(json, ShopInfo.class);
            if("0".equals(shopInfo.getCode())){
                List data = shopInfo.getData();
                adapter = new ShopCarAdapter(data);



                adapter.setOnCartListChangeListener(new ShopCarAdapter.onCartListChangeListener() {
                    @Override
                    public void onSellerCheckedChange(int groupPosition) {
                        boolean currentSellerAllProductSelected = adapter.isCurrentSellerAllProductSelected(groupPosition);
                        adapter.changeCurrentSellerAllProductsStatus(groupPosition, !currentSellerAllProductSelected);
                        adapter.notifyDataSetChanged();
                        //B.刷新底部数据
                        refreshSelectedAndTotalPriceAndTotalNumber();
                    }

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

                        //点击商品得checkbox
                        adapter.changeCurrentProductStatus(groupPosition,childPosition);
                        adapter.notifyDataSetChanged();
                        //B.刷新底部数据
                        refreshSelectedAndTotalPriceAndTotalNumber();
                    }

                    @Override
                    public void onProductNumberChange(int groupPosition, int childPosition, int number) {

                        //当加减被点击
                        adapter.changeCurrentProductNumber(groupPosition,childPosition,number);
                        adapter.notifyDataSetChanged();
                        //B.刷新底部数据
                        refreshSelectedAndTotalPriceAndTotalNumber();
                    }
                });

                expand_menu.setAdapter(adapter);

                for(int x=0; x

}

封装OKhttp
package com.www.shopcar;

import android.os.Handler;
import android.os.Looper;

import java.io.IOException;
import java.util.Map;
import java.util.concurrent.TimeUnit;

import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.FormBody;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class OkHttpUtils {

private final Handler mHandler;
private final OkHttpClient mOkHttpClient;
private static OkHttpUtils mOkHttpUtils;

private OkHttpUtils(){
    mHandler = new Handler(Looper.getMainLooper());
    mOkHttpClient = new OkHttpClient.Builder()
            .connectTimeout(10, TimeUnit.SECONDS)
            .writeTimeout(10, TimeUnit.SECONDS)
            .readTimeout(10, TimeUnit.SECONDS)
            .build();


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

public interface OkCallback{
    void onFile(Exception e);
    void onSuccess(String json);
}

public void doGet(String url, final OkCallback okCallback){
    final Request request = new Request.Builder()
            .get()
            .url(url)
            .build();

    Call call = mOkHttpClient.newCall(request);
    call.enqueue(new Callback() {
        @Override
        public void onFailure(Call call, final IOException e) {
            if(okCallback!=null){
                mHandler.post(new Runnable() {
                    @Override
                    public void run() {

                        okCallback.onFile(e);
                    }
                });
            }
        }

        @Override
        public void onResponse(Call call, Response response) throws IOException {

            if(response!=null&&response.isSuccessful()){
                final String json = response.body().string();
                mHandler.post(new Runnable() {
                    @Override
                    public void run() {
                        if(okCallback!=null){
                            okCallback.onSuccess(json);
                            return;
                        }

                    }
                });
            }
        }
    });

}

public void doPost(String url, Map map, final OkCallback okCallback) {
    FormBody.Builder builder = new FormBody.Builder();
    if (map != null) {
        for (String key : map.keySet()) {
            builder.add(key, map.get(key));
        }
    }
    FormBody formBody = builder.build();

    Request request = new Request.Builder()
            .post(formBody)
            .url(url)
            .build();
    final Call call = mOkHttpClient.newCall(request);
    call.enqueue(new Callback() {
        @Override
        public void onFailure(Call call, final IOException e) {
            if (okCallback != null) {
                mHandler.post(new Runnable() {
                    @Override
                    public void run() {
                        okCallback.onFile(e);
                    }
                });
            }
        }
        @Override
        public void onResponse(Call call, final Response response) throws IOException {

                if (response != null && response.isSuccessful()) {
                    final String json = response.body().string();
                    mHandler.post(new Runnable() {
                        @Override
                        public void run() {
                            if (okCallback != null) {
                                okCallback.onSuccess(json);
                            }
                        }
                    });
                }
        }
    });
}

}

加减的自定义控件
package com.www.shopcar;

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;

public class AddSubView extends LinearLayout implements View.OnClickListener {

private TextView sub_tv;
private TextView product_number_tv;
private TextView add_tv;
private int number=1;

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

public AddSubView(Context context, AttributeSet attrs) {
    this(context, attrs, 0);
}

public AddSubView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);

    View view = View.inflate(context, R.layout.addsubview, this);

    sub_tv=view.findViewById(R.id.sub_tv);
    product_number_tv=view.findViewById(R.id.product_number_tv);
    add_tv=view.findViewById(R.id.add_tv);


    sub_tv.setOnClickListener(this);
    add_tv.setOnClickListener(this);
}

@Override
public void onClick(View v) {
    switch (v.getId()){
        case R.id.sub_tv:
            if(number>1){
                --number;
                product_number_tv.setText(number+"");
                if(onNumberChangeListener!=null){
                    onNumberChangeListener.onNumberChange(number);
                }

            }else{
                Toast.makeText(getContext(), "不能再减了", Toast.LENGTH_SHORT).show();
            }
            break;

        case R.id.add_tv:
            ++number;
            product_number_tv.setText(number+"");
            if(onNumberChangeListener!=null){
                onNumberChangeListener.onNumberChange(number);
            }
            break;
    }
}

public int getNumber() {
    return number;
}

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

public interface OnNumberChangeListener{
    void onNumberChange(int num);
}

private OnNumberChangeListener onNumberChangeListener;

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

}

Adapter
package com.www.shopcar;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.CheckBox;
import android.widget.ImageView;
import android.widget.TextView;

import com.bumptech.glide.Glide;

import java.util.List;

class ShopCarAdapter extends BaseExpandableListAdapter {
private List mShopCarBean;

public ShopCarAdapter(List shopCarBean) {

    mShopCarBean=shopCarBean;

}

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

@Override
public int getChildrenCount(int groupPosition) {
    return mShopCarBean.get(groupPosition).getList()==null ? 0: mShopCarBean.get(groupPosition).getList().size();
}


@Override
public View getGroupView(final int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
    ShopInfo.DataBean dataBean = mShopCarBean.get(groupPosition);
    ParentViewHolder parentViewHolder;
    if (convertView == null) {
        convertView = View.inflate(parent.getContext(), R.layout.group_item, null);
        parentViewHolder = new ParentViewHolder(convertView);
        convertView.setTag(parentViewHolder);
    } else {
        parentViewHolder = (ParentViewHolder) convertView.getTag();
    }
    parentViewHolder.seller_name_tv.setText(dataBean.getSellerName());
    boolean currentSellerAllProductSelected = isCurrentSellerAllProductSelected(groupPosition);
    //更新UI
    parentViewHolder.seller_cb.setChecked(currentSellerAllProductSelected);

    parentViewHolder.seller_cb.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            //点击商家得checkBox
            if (onCartListChangeListener != null) {
                onCartListChangeListener.onSellerCheckedChange(groupPosition);
            }
        }
    });
    return convertView;

}

@Override
public View getChildView(final int groupPosition, final int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
    ShopInfo.DataBean dataBean = mShopCarBean.get(groupPosition);
    List list = dataBean.getList();

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

    ChildViewHolder childViewHolder;

    if (convertView == null) {
        convertView = View.inflate(parent.getContext(), R.layout.child_item, null);
        childViewHolder = new ChildViewHolder(convertView);
        convertView.setTag(childViewHolder);
    } else {
        childViewHolder=(ChildViewHolder)convertView.getTag();
    }
    childViewHolder.product_title_name_tv.setText(listBean.getTitle());
    childViewHolder.product_price_tv.setText(listBean.getPrice()+"");
    childViewHolder.child_cb.setChecked(listBean.getSelected() == 1);

    childViewHolder.add_remove_view.setNumber(listBean.getNum());


    String image = listBean.getImages();
    String[] split = image.split("\\|");
    String s = split[0];

    Glide.with(convertView).load(s).into(childViewHolder.product_icon_iv);

    childViewHolder.child_cb.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            //点击商品得checkBox
            if (onCartListChangeListener != null) {
                onCartListChangeListener.onProductCheckedChange(groupPosition, childPosition);
            }
        }
    });

    childViewHolder.add_remove_view.setOnNumberChangeListener(new AddSubView.OnNumberChangeListener() {
        @Override
        public void onNumberChange(int num) {
            //拿到商品最新得数量
            if (onCartListChangeListener != null) {
                onCartListChangeListener.onProductNumberChange(groupPosition, childPosition, num);
            }
        }
    });

    return convertView;
}

//当前商家所有商品是否被选中
public boolean isCurrentSellerAllProductSelected(int groupPosition) {
    ShopInfo.DataBean dataBean = mShopCarBean.get(groupPosition);
    //拿到商家所有的商品
    List list = dataBean.getList();

    //Bean类中有一个selected来判断是否选中,未选中是0
    for (ShopInfo.DataBean.ListBean listBean : list) {
        //只要有一个未选中，商家就直接未选中
        if (listBean.getSelected() == 0) {
            return false;
        }
    }
    return true;
}



//所有商品是否被选中,双重for循环,里面的集合套集合取数据
public boolean isAllProductsSelected() {
    for (int i = 0; i < mShopCarBean.size(); i++) {
        ShopInfo.DataBean dataBean = mShopCarBean.get(i);
        List list = dataBean.getList();
        for (int j = 0; j < list.size(); j++) {
            if (list.get(j).getSelected() == 0) {
                return false;
            }
        }
    }
    return true;
}


//计算商品总的数量
public int calculateTotalNumber() {
    int totalNumber = 0;
    for (int i = 0; i < mShopCarBean.size(); i++) {
        ShopInfo.DataBean dataBean = mShopCarBean.get(i);
        List list = dataBean.getList();
        for (int j = 0; j < list.size(); j++) {
            //只要是选中状态
            if (list.get(j).getSelected() == 1) {
                int num = list.get(j).getNum();
                totalNumber += num;
            }
        }
    }
    return totalNumber;
}

/**
 *计算总价
 */
public float calculateTotalPrice() {
    float totalPrice = 0;
    for (int i = 0; i < mShopCarBean.size(); i++) {
        ShopInfo.DataBean dataBean = mShopCarBean.get(i);
        List list = dataBean.getList();
        for (int j = 0; j < list.size(); j++) {
            //只要是选中状态
            if (list.get(j).getSelected() == 1) {
                float price = list.get(j).getPrice();
                int num = list.get(j).getNum();
                totalPrice += price * num;
            }
        }
    }
    return totalPrice;
}




//当商家得checkbox被点击得时候调用，设置当前商家得所有商品得状态--------商家组其所有的商品
public void changeCurrentSellerAllProductsStatus(int groupPosition, boolean isSelected) {
    ShopInfo.DataBean dataBean = mShopCarBean.get(groupPosition);
    List listBeans = dataBean.getList();
    for (int i = 0; i < listBeans.size(); i++) {
        ShopInfo.DataBean.ListBean listBean = listBeans.get(i);
        listBean.setSelected(isSelected ? 1 : 0);
    }
}

//当商品得checkbox被点击得时候调用，改变当前商品状态---------商品子条目
public void changeCurrentProductStatus(int groupPosition, int childPosition) {
    ShopInfo.DataBean dataBean = mShopCarBean.get(groupPosition);
    List listBeans = dataBean.getList();
    ShopInfo.DataBean.ListBean listBean = listBeans.get(childPosition);
    listBean.setSelected(listBean.getSelected() == 0 ? 1 : 0);
}

//设置所有商品得状态
public void changeAllProductsStatus(boolean selected) {
    for (int i = 0; i < mShopCarBean.size(); i++) {
        ShopInfo.DataBean dataBean = mShopCarBean.get(i);
        List list = dataBean.getList();
        for (int j = 0; j < list.size(); j++) {
            list.get(j).setSelected(selected?1:0);
        }
    }
}

//当加减器被点击得时候调用，改变当前商品得数量
public void changeCurrentProductNumber(int groupPosition, int childPosition, int number) {
    ShopInfo.DataBean dataBean = mShopCarBean.get(groupPosition);
    List listBeans = dataBean.getList();
    ShopInfo.DataBean.ListBean listBean = listBeans.get(childPosition);
    listBean.setNum(number);
}

onCartListChangeListener onCartListChangeListener;

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

public interface onCartListChangeListener {

    void onSellerCheckedChange(int groupPosition);

    void onProductCheckedChange(int groupPosition, int childPosition);

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




@Override
public Object getGroup(int groupPosition) {
    return null;
}

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

class ParentViewHolder {
    public CheckBox seller_cb;
    public TextView seller_name_tv;

    public ParentViewHolder(View rootView) {
        seller_cb =  rootView.findViewById(R.id.seller_cb);
        seller_name_tv =  rootView.findViewById(R.id.seller_name_tv);
    }
}
class ChildViewHolder {
    public CheckBox child_cb;
    public ImageView product_icon_iv;
    public TextView product_title_name_tv;
    public TextView product_price_tv;
    public AddSubView add_remove_view;

    public ChildViewHolder(View rootView) {
        child_cb =  rootView.findViewById(R.id.child_cb);
        product_icon_iv =  rootView.findViewById(R.id.product_icon_iv);
        product_title_name_tv =  rootView.findViewById(R.id.product_title_name_tv);
        product_price_tv =  rootView.findViewById(R.id.product_price_tv);
        add_remove_view =  rootView.findViewById(R.id.add_remove_view);
    }
}

}