购物车

主界面

<?  version=\"1.0\" encoding=\"utf-8\"?>
<LinearLayout   ns:android=\"http://schemas.android.com/apk/res/android\"
    android:layout_width=\"match_parent\"
    android:layout_height=\"match_parent\"
    android:orientation=\"vertical\">
    <TextView
        android:layout_width=\"match_parent\"
        android:layout_height=\"wrap_content\"
        android:background=\"@color/colorAccent\"
        android:gravity=\"center\"
        android:padding=\"10dp\"
        android:text=\"购物车\"
        android:textColor=\"#fff\"
        android:textSize=\"25sp\" />
    <ExpandableListView
        android:id=\"@+id/list_cart\"
        android:layout_width=\"match_parent\"
        android:layout_height=\"wrap_content\"
        android:layout_weight=\"1\" />
    <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 >

fragment这代码

public class two_frag extends Fragment implements CallBacks<List<Shop>>,CartAdapter2.TotalPriceListener{
    private TextView mSumPrice;
    private CheckBox mCheckAll;
    private CartAdapter2 mCartAdapter;
    private ExpandableListView mGoodsList;
    private CartPresenter cartPresenter = new CartPresenter(this);
    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view=inflater.inflate(R.layout.item_two,container,false);
        mSumPrice=view.findViewById(R.id.goods_sum_price);
        mCheckAll = view.findViewById(R.id.check_all);
        mCheckAll.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                mCartAdapter.checkAll(isChecked);
            }
        });
        mGoodsList = view.findViewById(R.id.list_cart);
        mCartAdapter = new CartAdapter2();
        mGoodsList.setAdapter(mCartAdapter);
        mCartAdapter.setTotalPriceListener(this);//设置总价回调器
        mGoodsList.setGroupIndicator(null);
        mGoodsList.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
            @Override
            public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {
                return true;
            }
        });
        cartPresenter.requestData();
        return view;
    }
    @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(getActivity(), result.getCode() + \"   \" + result.getMsg(), Toast.LENGTH_LONG).show();
    }

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

增加减少的按钮

<?  version=\"1.0\" encoding=\"utf-8\"?>
<LinearLayout  ns:android=\"http://schemas.android.com/apk/res/android\"
    android:layout_width=\"match_parent\"
    android:layout_height=\"match_parent\">
    <TextView
        android:id=\"@+id/btn_add\"
        android:layout_width=\"30dp\"
        android:layout_height=\"30dp\"
        android:background=\"@drawable/add\"
        android:focusable=\"false\"
        android:textSize=\"20sp\"
        android:gravity=\"center\"
        android:text=\"+\" />

    <TextView
        android:id=\"@+id/text_number\"
        android:layout_width=\"60dp\"
        android:layout_height=\"30dp\"
        android:gravity=\"center\"
        android:textSize=\"14sp\"
        android:text=\"1000\" />

    <TextView
        android:id=\"@+id/btn_sub\"
        android:layout_width=\"30dp\"
        android:layout_height=\"30dp\"
        android:textSize=\"20sp\"
        android:focusable=\"false\"
        android:gravity=\"center\"
        android:background=\"@drawable/accept\"
        android:text=\"-\" />
</LinearLayout>

增加减少的java

public class AddSubLayout extends LinearLayout implements View. Listener {
    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();
    }

    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.set Listener(this);
        mSubBtn.set Listener(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  (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);
    }
}

二级列表第一级的布局

<?  version=\"1.0\" encoding=\"utf-8\"?>
<LinearLayout  ns: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>

二级列表孩子的布局

<?  version=\"1.0\" encoding=\"utf-8\"?>
<RelativeLayout  ns: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/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\"/>
    <com.example.demo4.http.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.example.demo4.http.AddSubLayout>
    <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\"/>


</RelativeLayout>

Adapter加载数据进入二级列表

public class CartAdapter2 extends  ExpandableListAdapter {
    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   getGroup(int groupPosition) {
        return mList.get(groupPosition);
    }

    @Override
    public   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.item_father,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());
        holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                shop.setCheck(isChecked);
                List<Goods> goodsList=mList.get(groupPosition).getList();
                for (int i=0;i<goodsList.size();i++){
                    goodsList.get(i).setSellerid(isChecked?1:0);
                }
                notifyDataSetChanged();
                calculatePrice();
            }
        });
        return convertView;
    }

    @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.item_son,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.get ());
        holder.price.setText(\"单价：\"+goods.getPrice());//单价
        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());
        if (parent.getContext()!=null){
            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;
    }
    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();
    }
    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return false;
    }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;
    }
    class GroupHodler {
        CheckBox checkBox;
    }
    public interface TotalPriceListener{
        void totalPrice(double totalPrice);
    }
}

定义全局类

public class DTApplication extends Application {
    private static DTApplication instance;
    private SharedPreferences mSharedPreferences;

    @Override
    public void onCreate() {
        super.onCreate();
        instance = this;
        mSharedPreferences = getSharedPreferences(\"application\",
                Context.MODE_PRIVATE);
//        JPushInterface.setDebugMode(true);
//        JPushInterface.init(this);     		// 初始化 JPush
    }

    public static DTApplication getInstance() {
        return instance;
    }

    public SharedPreferences getShare() {
        return mSharedPreferences;
    }
}