二级列表简单实现二级列表

   二级列表控件：

   

ExpandableListView

  一般购物车都是有个表头 有个表位所以要用一个

ScrollView 控件包裹着，一般会出现滑动冲突事件所以需要自定义一个二级列表

public class MyExpandableListView extends ExpandableListView {
    public MyExpandableListView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    //解决滑动事件冲突
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int height = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE>>2,MeasureSpec.AT_MOST);
        super.onMeasure(widthMeasureSpec, height);
    }
}

注意这里需要在bean类里写一个自定义的属性为了记录一级列表的checkbox框的状态：

public boolean isGroupChecked() {
    return isGroupChecked;
}


public void setGroupChecked(boolean groupChecked) {
    isGroupChecked = groupChecked;
}

private boolean isGroupChecked;

//首次进入app时isGeoupchecked为false

直接看适配器的逻辑代码，重点地方都有注释的：

public class Myadapter extends BaseExpandableListAdapter {
    private Handler handler;
    private Context context;
    private List group_list;
    private List>child_list;

    public Myadapter(Handler handler, Context context, List group_list, List> child_list) {
        this.handler = handler;
        this.context = context;
        this.group_list = group_list;
        this.child_list = child_list;
    }

    @Override
    public int getGroupCount() {
        return group_list.size();
    }

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

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

    @Override
    public Object getChild(int groupPosition, int childPosition) {
        return child_list.get(groupPosition).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 true;
    }

    @Override
    public View getGroupView(final int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
        GroupHolder holder;
        if(convertView==null){
            convertView = View.inflate(context, R.layout.group_item, null);
            holder = new GroupHolder();
            holder.group_checked=convertView.findViewById(R.id.group_checked);
            holder.group_text=convertView.findViewById(R.id.group_text);
            convertView.setTag(holder);
        }else {
            holder= (GroupHolder) convertView.getTag();
        }
        final Bean.DataBean dataBean = group_list.get(groupPosition);
        holder.group_checked.setChecked(dataBean.isGroupChecked());
        holder.group_text.setText(dataBean.getSellerName());
        holder.group_checked.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //改变当前以及列表的状态，不与初始化的相等
                dataBean.setGroupChecked(!dataBean.isGroupChecked());
                //根据当前一级状态改变二级列表的值
                changeChildState(groupPosition,dataBean.isGroupChecked());
                //通过判断一级的是否选中，来设置是否为全部选中
                changeAllState(isAllGroupChecked());
                //发送价格数量
                sendPriceAndCount();
                notifyDataSetChanged();
            }
        });

        return convertView;
    }

    @Override
    public View getChildView(final int groupPosition, int childPosition, boolean isLastChild, View view, ViewGroup parent) {
         ChildHolder holder;
        if(view==null){
            view = View.inflate(context, R.layout.child_item, null);
            holder=new ChildHolder();

            holder.text_add = view.findViewById(R.id.text_add);
            holder.text_num = view.findViewById(R.id.text_num);
            holder.text_jian = view.findViewById(R.id.text_jian);
            holder.text_title = view.findViewById(R.id.text_title);
            holder.text_price = view.findViewById(R.id.text_price);
            holder.image_good = view.findViewById(R.id.image_good);
            holder.check_child = view.findViewById(R.id.check_child);

            view.setTag(holder);
        }else {
            holder = (ChildHolder) view.getTag();
        }
        final Bean.DataBean.ListBean listBean = child_list.get(groupPosition).get(childPosition);
        holder.text_num.setText(listBean.getNum()+"");//......注意
        holder.text_price.setText("¥"+listBean.getPrice());
        holder.text_title.setText(listBean.getTitle());
        ImageLoader.getInstance().displayImage(listBean.getImages().split("!")[0],holder.image_good);
        holder.check_child.setChecked(listBean.getSelected()==0? false:true);
        holder.check_child.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                listBean.setSelected(listBean.getSelected() ==0? 1:0);
                sendPriceAndCount();
                if(listBean.getSelected()==1){
                   if(isAllChildSelected(groupPosition)){
                       //如果全部选中改变当前状态
                       changeGroupState(groupPosition,true);
                       //.确定是否改变全选
                       changeAllState(isAllGroupChecked());
                   }

                }else {
                    //如果没有选中改变一下当前组的状态
                    changeGroupState(groupPosition,false);
                    //.确定是否改变全选
                    changeAllState(isAllGroupChecked());
                }
                //刷新适配器
                notifyDataSetChanged();
            }
        });
        holder.text_add.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                listBean.setNum(listBean.getNum()+1);
                if (listBean.getSelected()==1){
                    sendPriceAndCount();
                }
                notifyDataSetChanged();
            }
        });
        holder.text_jian.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int num = listBean.getNum();

                if (num == 1){
                    return;
                }

                listBean.setNum(num-1);
                if (listBean.getSelected() == 1){
                    sendPriceAndCount();
                }

                notifyDataSetChanged();
            }
        });
        return view;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
        //子条目是否能点击
    }

   //通过二级列表 改变一级列表的状态设置父控件是否选中
    private void changeGroupState(int groupPosition, boolean b) {


        group_list.get(groupPosition).setGroupChecked(b);

    }

    //子布局是否选中
  //二级列表是否全部选中
    private boolean isAllChildSelected(int groupPosition) {
        List listBeans = child_list.get(groupPosition);

        for (int i=0;iif (listBeans.get(i).getSelected() == 0){

                return false;
            }
        }

        return true;
    }

//设置总价
    private  void  sendPriceAndCount(){
        double price=0;
        int count=0 ;
        for (int i = 0; i <group_list.size() ; i++) {
            List list = group_list.get(i).getList();
            for (int j = 0; j if(listBean.getSelected()==1){
                    //当二级列表选中时计算价格，和物品的个数
                    price += listBean.getPrice()* listBean.getNum();
                    //单价*数目
                    count += listBean.getNum();
                }
            }
        }
        CountPriceBean countPriceBean = new CountPriceBean(price, count);
        //实例化 购物车计算价钱的bean类，把得到的总数总价钱存入
        Message msg = Message.obtain();
        msg.what = 0;
        //设置标识符待主类接收
        msg.obj = countPriceBean;

        handler.sendMessage(msg);
        //把值存入handler值 等待接收
    }


 //设置父控件全选
    private  boolean isAllGroupChecked(){

        for (int i = 0; i <group_list.size() ; i++) {
            //isGroupChecked 初始值为false当点击的时候为yrue所以 ！=isGroupChecked就是false
            if(!group_list.get(i).isGroupChecked()){
                return false;
            }
        }
       return true;
    }

    //设置所以元素全选
    public void changeAllState(boolean allGroupChecked){
        //通过得到一级列表的所有状态设置 全选的值
        Message msg = Message.obtain();
         msg.what=1;
        msg.obj=allGroupChecked;
        handler.sendMessage(msg);
        //主要就是实现 通过一级二级的状态改变主类里checkbox的值
    }


    public void changeChildState(int groupPosition, boolean groupChecked){
        List listBeen = child_list.get(groupPosition);
        //通过一级列表的状态 设置子二级列表的全部状态
        for (int i = 0; i 1:0);
        }
    }

    public void setIfCheckAll(boolean checked) {
       //本方法是为了通过主类里的checkbox改变一级二级列表的值
        for (int i = 0;i<group_list.size();i++){
            Bean.DataBean dataBean = group_list.get(i);
            //设置组上面的checkBox是否选中
            dataBean.setGroupChecked(checked);

            List listBeans = dataBean.getList();
            for (int j = 0; j< listBeans.size(); j++){
                //改变是否选中的状态...数据应该变的是
                listBeans.get(j).setSelected(checked? 1:0);
            }

        }

        //计算价钱和数量并且发送到mainActivity显示
        sendPriceAndCount();

        //刷新适配器
        notifyDataSetChanged();

    }
    private class GroupHolder{
        CheckBox group_checked;
        TextView group_text;
    }

    private class ChildHolder{
        CheckBox check_child;
        ImageView image_good;
        TextView text_title;
        TextView text_price;
        TextView text_jian;
        TextView text_num;
        TextView text_add;
    }

}

 
下面是主类使用碎片fragment实现的所以注意上下文的参数：

 

public class gwc extends Fragment {

    private MyExpandableListView expandableListView;
    private CheckBox all_check;
    private TextView price;
    private Button buy;
    //通过Handler接收适配器的值改变主线程的UI
    private Handler handler =new Handler(){
        @Override
        public void handleMessage(Message msg) {
            if (msg.what == 0){
                CountPriceBean countPriceBean = (CountPriceBean) msg.obj;

                //设置
                price.setText("合计:¥"+countPriceBean.getPrice());
                buy.setText("去结算("+countPriceBean.getCount()+")");
            }else  if (msg.what == 1){//改变全选
                boolean flag = (boolean) msg.obj;

                all_check.setChecked(flag);
            }
        }
    };
    private Myadapter myadapter;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View v = View.inflate(getActivity(), R.layout.gwc, null);
        expandableListView = (MyExpandableListView)v. findViewById(R.id.expandableListView);
        all_check = (CheckBox)v. findViewById(R.id.all_check);
        price = (TextView) v.findViewById(R.id.price);
        buy = (Button) v.findViewById(R.id.buy);
        expandableListView.setGroupIndicator(null);//暂时用不到此属性所以为false
        TextView bt = v.findViewById(R.id.but);
        bt.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                HashMap map = new HashMap<>();
                map.put("uid","2856");
                OkHttp3Utils.doPost("http://120.27.23.105/product/getCarts",map, new GsonObjectCallback() {
                    @Override
                    public void onUi(Bean bean) {
                        if (bean.getData()!=null){
                        Log.e("**", bean.getMsg());
                            List data = bean.getData();
                            List> listChilds = new ArrayList<>();
                            for (int i = 0; i < data.size(); i++) {
                                listChilds.add(data.get(i).getList());
                            }
                            myadapter = new Myadapter(handler,getActivity(), data, listChilds);
                            expandableListView.setAdapter(myadapter);
                            for (int i=0;i//设置一级列表默认展开
                                expandableListView.expandGroup(i);
                            }
                              all_check.setOnClickListener(new View.OnClickListener() {
                                  @Override
                                  public void onClick(View v) {
                                      myadapter.setIfCheckAll(all_check.isChecked());
                                  }
                              });
                        }
                    }

                    @Override
                    public void onFailed(Call call, IOException e) {

                    }
                });

            }

        });


        return v;
    }
}

下面是主类的xml文件：

xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
     <RelativeLayout
         android:layout_width="match_parent"
         android:layout_height="0dp"
         android:layout_weight="1"
         >
          <TextView
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:text="购物车"
              android:layout_centerInParent="true"
              android:textSize="25sp"
              android:id="@+id/but"
              />
     RelativeLayout>

     <ScrollView
         android:layout_width="match_parent"
         android:layout_height="0dp"
         android:layout_weight="8"
         >
          <LinearLayout
              android:layout_width="match_parent"
              android:layout_height="wrap_content"

              >

               <com.bwei.ssp.home_work.Fragment.shopcate.view.MyExpandableListView
                   android:id="@+id/expandableListView"
                   android:layout_width="match_parent"
                   android:layout_height="match_parent"/>

          LinearLayout>
     ScrollView>
     <RelativeLayout
         android:layout_width="match_parent"
         android:layout_height="0dp"
         android:layout_weight="1"

         >
          <CheckBox
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:id="@+id/all_check"
              android:layout_centerVertical="true"
              />
          <TextView
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:text="全选"
              android:textSize="19sp"
              android:layout_marginLeft="40dp"
              android:layout_centerVertical="true"
              />
          <TextView
              android:layout_centerInParent="true"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:text="￥0.0"
              android:id="@+id/price"
              android:textColor="#ff9933"

              />
          <LinearLayout
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:layout_alignParentRight="true"
              >
               <Button
                   android:layout_width="70dp"
                   android:layout_height="wrap_content"
                   android:text="删除"
                   android:id="@+id/del"
                   android:background="#cc6600"
                   />
               <Button
                   android:layout_width="70dp"
                   android:layout_height="wrap_content"
                   android:text="购买"
                   android:background="#ff0066"
                   android:id="@+id/buy"
                   />
          LinearLayout>
     RelativeLayout>
LinearLayout>

 一级列表的布局：

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="match_parent">
      <CheckBox
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:id="@+id/group_checked"
          android:layout_marginLeft="10dp"
          />
    <TextView
        android:layout_marginLeft="10dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="天猫运营"
        android:id="@+id/group_text"
        android:textSize="20dp"
        />
LinearLayout>

二级列表的努布局：

xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:padding="10dp"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <CheckBox
        android:layout_centerVertical="true"
        android:id="@+id/check_child"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <ImageView
        android:id="@+id/image_good"
        android:layout_centerVertical="true"
        android:layout_toRightOf="@+id/check_child"
        android:layout_marginLeft="10dp"
        android:layout_width="80dp"
        android:layout_height="80dp" />

    <TextView
        android:id="@+id/text_title"
        android:layout_toRightOf="@+id/image_good"
        android:layout_marginLeft="10dp"
        android:layout_alignTop="@+id/image_good"
        android:maxLines="2"
        android:minLines="2"
        android:text="我是手机"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/text_price"
        android:layout_toRightOf="@+id/image_good"
        android:layout_marginLeft="10dp"
        android:layout_alignBottom="@+id/image_good"
        android:text="¥99.99"
        android:textColor="#ff0000"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <LinearLayout
        android:layout_alignParentRight="true"
        android:layout_alignBottom="@+id/image_good"
        android:orientation="horizontal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">

        <TextView
            android:id="@+id/text_jian"
            android:text="一"
            android:padding="5dp"
            android:background="@drawable/bian_kuang_line"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />

        <TextView
            android:gravity="center"
            android:id="@+id/text_num"
            android:paddingLeft="10dp"
            android:paddingRight="10dp"
            android:background="@drawable/bian_kuang_line"
            android:layout_width="wrap_content"
            android:layout_height="match_parent" />

        <TextView
            android:id="@+id/text_add"
            android:text="十"
            android:padding="5dp"
            android:background="@drawable/bian_kuang_line"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />

    LinearLayout>


RelativeLayout>