重写BaseExpandableListAdapter实现Group和Child上的按钮均可点击

由于项目需要，实现一个二级列表，显示4s店，并且需要实现组和子项同时可以选择，并且将选择的项返回给activity。

1、首先建立一个shop实体类，

public class Shop implements Serializable {    private long id;    private String name;    private String fullName;    private String address;    private String longitude;    private String latitude;    private int shopType;    private long parentId;    private boolean isChecked = false;    private String sortLetters; // 显示数据拼音的首字母    List<Shop> ChildShops;(子店集合，即某一个Group下的所有项)        get,set方法省略...}

2、从服务器获取数据，通过Gson转换工具，直接生成我们所需要的list<Shop>集合。

      JSONArray parentItem = new JSONArray(response);// response是从服务器获取的json格式的字符串     for(int i=0;i<parentItem.length();i++){        Shop shop = new Gson().fromJson(parentItem.get(i).toString(),Shop.class);        shopList.add(shop);// 将一个个shop加入到shopList集合，用于传递到adapter.     }

3、显示数据

     shopAdapter = new ShopAdapter(getApplicationContext(),list);// shopAdapter即重写adapter

接下来，我将重点讲这个adapter的重写

先来预览一下效果

4、定义group和child的视图

shop_parent_item.xml布局如下：<?xml version="1.0" encoding="utf-8"?><LinearLayout    xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical"    android:layout_width="match_parent"    android:background="@color/white"    android:layout_height="wrap_content">       <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:orientation="horizontal">        <LinearLayout            android:layout_width="30dp"            android:layout_height="match_parent">            <ImageView                android:id="@+id/arrowRight"                android:layout_width="match_parent"                android:layout_height="match_parent"                android:src="@drawable/arrow_right_18"/>        </LinearLayout>        <LinearLayout            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:orientation="vertical"            android:layout_weight="1">            <TextView                android:id="@+id/parent_shop_name"                android:layout_width="match_parent"                android:layout_height="20dp"                android:text=""                android:textColor="@color/colorHeader"                android:textSize="14sp"/>            <TextView                android:id="@+id/parent_shop_address"                android:layout_width="match_parent"                android:layout_height="20dp"                android:text=""                android:textSize="10sp"                android:textColor="@color/gray"                android:layout_marginTop="5dp"/>        </LinearLayout>        <LinearLayout            android:layout_width="wrap_content"            android:layout_height="match_parent"            android:layout_marginRight="20dp"            android:layout_marginTop="10dp"            android:layout_marginLeft="10dp">            <ImageView                android:id="@+id/parent_shop_add"                android:layout_width="30dp"                android:layout_height="30dp"                android:src="@drawable/shopadd"/>        </LinearLayout>    </LinearLayout></LinearLayout>

shop_child_item.xml定义如下：<?xml version="1.0" encoding="utf-8"?><LinearLayout    xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical"    android:layout_width="match_parent"    android:layout_height="50dp">    <LinearLayout        android:layout_width="match_parent"        android:layout_height="38dp"        android:orientation="horizontal">        <LinearLayout            android:layout_width="wrap_content"            android:layout_height="match_parent"            android:layout_marginLeft="30dp">            <TextView                android:id="@+id/child_shop_type"                android:layout_width="30dp"                android:layout_height="match_parent"                android:gravity="center"                android:textColor="@color/gray"                android:textSize="10sp"                android:text=""/>        </LinearLayout>        <LinearLayout            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:orientation="vertical"            android:layout_weight="1">            <TextView                android:id="@+id/child_shop_name"                android:layout_width="match_parent"                android:layout_height="20dp"                android:text=""                android:textColor="@color/skyblue"                android:textSize="14sp"/>            <TextView                android:id="@+id/child_shop_address"                android:layout_width="match_parent"                android:layout_height="15dp"                android:text=""                android:textSize="10sp"                android:textColor="@color/gray"                android:layout_marginTop="3dp"/>        </LinearLayout>        <LinearLayout            android:layout_width="wrap_content"            android:layout_height="match_parent"            android:layout_marginRight="20dp"            android:layout_marginTop="5dp"            android:layout_marginLeft="10dp">            <ImageView                android:id="@+id/child_shop_add"                android:layout_width="30dp"                android:layout_height="30dp"                android:src="@drawable/shopadd"/>        </LinearLayout>    </LinearLayout>    <View        android:layout_width="match_parent"        android:layout_height="1px"        android:background="@color/gray"        /></LinearLayout>

5、重写BaseExpandableListAdapter，实现想要的结果。直接上代码，注释写的很清楚：

package com.iftech.zhongdugps.trace.adapter;/** * Created by Tanghuosong on 2017/3/17. */public class ShopAdapter extends BaseExpandableListAdapter {    private List<Shop> shopList = new ArrayList<>();    private LayoutInflater inflater;    private List<Shop> shopChecked = new ArrayList<>();    ParentViewHolder parentViewHolder;    ChildViewHolder childViewHolder;    // 构造函数，传入shops即activity需要显示的list    public ShopAdapter(Context context,List<Shop> shops){        this.shopList = shops;        this.inflater = LayoutInflater.from(context);    }    @Override    public int getChildrenCount(int groupPosition) {        return shopList.get(groupPosition).getChildShops().size();    }    @Override    public int getGroupCount() {        return shopList.size();    }    @Override    public View getGroupView(final int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {        final Shop parentShop = getGroup(groupPosition);        if(convertView==null){            parentViewHolder = new ParentViewHolder();            convertView = inflater.inflate( R.layout.shop_parent_item, null);            parentViewHolder.parent_shop_name = (TextView) convertView.findViewById(R.id.parent_shop_name);            parentViewHolder.parent_shop_address = (TextView) convertView.findViewById(R.id.parent_shop_address);            parentViewHolder.parent_shop_add = (ImageView) convertView.findViewById(R.id.parent_shop_add);            parentViewHolder.arrowRight = (ImageView) convertView.findViewById(R.id.arrowRight);            convertView.setTag(parentViewHolder);        }else{            parentViewHolder = (ParentViewHolder)convertView.getTag();        }        parentViewHolder.parent_shop_add.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                if(!parentShop.isChecked()){// 判断是否已经选择，选择过的再次点击则移除                    shopChecked.add(parentShop);                    parentShop.setChecked(true);// 点击添加按钮时将该shop加入到集合中，方便activity获得所有已经选中的。                }else {                    parentShop.setChecked(false);// 点击删除按钮，将该shop从集合中移除，保证选择的正确性。                    shopChecked.remove(parentShop);                }                ShopAdapter.this.notifyDataSetChanged();// 通知adapter进行更新            }        });         // 以下这段是防止右侧的点击按钮出现混乱，做的标记        if(parentShop.isChecked()){            parentViewHolder.parent_shop_add.setImageResource(R.drawable.shopsub);// 选择过的图片显示红叉，代表可以删除        }else{            parentViewHolder.parent_shop_add.setImageResource(R.drawable.shopadd);// 未选中的图标显示绿色的加号，表示可以选择        }               if(getChildrenCount(groupPosition)==0){// 当某一个组的子项数为0时，左侧箭头隐藏            parentViewHolder.arrowRight.setVisibility(View.GONE);        }else{            parentViewHolder.arrowRight.setVisibility(View.VISIBLE);        }        parentViewHolder.parent_shop_name.setText(parentShop.getName());        parentViewHolder.parent_shop_address.setText(parentShop.getAddress());        return convertView;    }    @Override    public View getChildView(final int groupPosition,final int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {        final Shop childShop = getChild(groupPosition,childPosition);        if(convertView == null){            childViewHolder = new ChildViewHolder();            convertView = inflater.inflate(R.layout.shop_child_item,null);            childViewHolder.child_shop_type = (TextView) convertView.findViewById(R.id.child_shop_type);            childViewHolder.child_shop_name = (TextView) convertView.findViewById(R.id.child_shop_name);            childViewHolder.child_shop_address = (TextView) convertView.findViewById(R.id.child_shop_address);            childViewHolder.child_shop_add = (ImageView) convertView.findViewById(R.id.child_shop_add);            convertView.setTag(childViewHolder);        }else{            childViewHolder = (ChildViewHolder) convertView.getTag();        }        // 以下这是该项目特殊需求，读者可以自动忽略       if((childShop.getShopType())==2){            childViewHolder.child_shop_type.setText("二库");        }else{            childViewHolder.child_shop_type.setText("二网");        }        // 理解同parentViewHolder        childViewHolder.child_shop_add.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                if(!childShop.isChecked()){                    childShop.setChecked(true);                    shopChecked.add(childShop);                }else{                    childShop.setChecked(false);                    shopChecked.remove(childShop);                }                ShopAdapter.this.notifyDataSetChanged();            }        });        if(childShop.isChecked()){            childViewHolder.child_shop_add.setImageResource(R.drawable.shopsub);        }else{            childViewHolder.child_shop_add.setImageResource(R.drawable.shopadd);        }        childViewHolder.child_shop_name.setText(childShop.getName());        childViewHolder.child_shop_address.setText(childShop.getAddress());        return convertView;    }    @Override    public long getChildId(int groupPosition, int childPosition) {        return childPosition;    }    @Override    public long getGroupId(int groupPosition) {        return groupPosition;    }    @Override    public Shop getChild(int groupPosition, int childPosition) {        return shopList.get(groupPosition).getChildShops().get(childPosition);    }    @Override    public Shop getGroup(int groupPosition) {        return shopList.get(groupPosition);    }    @Override    public boolean isChildSelectable(int groupPosition, int childPosition) {        return false;    }    @Override    public void onGroupExpanded(int groupPosition) {        super.onGroupExpanded(groupPosition);    }    @Override    public boolean hasStableIds() {        return true;    }     public List<Shop> getShopChecked() {        return shopChecked;    }    public void setShopChecked(List<Shop> shopChecked) {        this.shopChecked = shopChecked;    }    final static class ParentViewHolder{        private TextView parent_shop_name;        private TextView parent_shop_address;        private ImageView parent_shop_add;        private TextView catalog;        private ImageView arrowRight;        private LinearLayout cb_layout;    }    final static class ChildViewHolder{        private TextView child_shop_type;        private TextView child_shop_name;        private TextView child_shop_address;        private ImageView child_shop_add;    }  }

6、关于activity如何获得在adapter中选择的shop，有很多种方式，例如使用接口接听，观察者模式，而我在这里使用的最简便的方法，观察者模式（不懂观察者模式，请自行google）。

       shopAdapter.registerDataSetObserver(new DataSetObserver() {           @Override           public void onChanged() {               super.onChanged();               selectShops = shopAdapter.getShopChecked();               for(Shop shop :selectShops){                    Logger.d("Shop",shop.toString());                }                   Logger.d("已选择项数","===================>"+selectShops.size());           }        });

每当adapter中点击了按钮，不管是删除或者添加都可以监听到改变

7、图片中的右侧的字母搜索本篇不做介绍，想了解的也可以google查看。还有一些小的欠缺，由于时间原因没来得及做完。例如左侧箭头在该group展开时换成向下的箭头，待完善后补充。