可折叠的listview 之ExpandableListView基本使用

先看效果

demo实现
其他的方法和ListView的方法一样,下面来看看具体demo的实现
首先布局文件很简单,就一个控件为:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    tools:context="com.duanlian.expendablelistviewdemo.MainActivity">
    <ExpandableListView
        android:id="@+id/expendablelistview"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</RelativeLayout>

Activity的代码和用ListView的是一样的,创建一个adapter和两个 数据源,然后绑定,具体如下:

package com.duanlian.expendablelistviewdemo;
 
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ExpandableListView;
 
import com.duanlian.expendablelistviewdemo.adapter.MyAdapter;
 
import java.util.ArrayList;
import java.util.List;
 
public class MainActivity extends AppCompatActivity {
    private ExpandableListView expandableListView;
    private MyAdapter myAdapter;
    private List<String> groupList;
    private List<List<String>> childList;
 
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
    }
 
    private void initView() {
        expandableListView = (ExpandableListView) findViewById(R.id.expendablelistview);
        groupList = new ArrayList<>();
        childList = new ArrayList<>();
        addData("幼稚园同学",new String[]{"周杰伦","江一燕 ","佟丽娅","高圆圆","刘诗诗","刘亦菲","angleBaby","张静初","张含韵",});
        addData("小学同学",new String[]{"光头强","熊大","熊二","妙蛙种子","比卡丘","双蛋瓦斯","贪吃蛇"});
        addData("初中同学",new String[]{"苍井空","小泽玛利亚","吉泽明步","波多野结衣","爱川美里菜","小川阿佐美","桃谷绘里香","泷泽萝拉","北原多香子","石川施恩惠","北条麻妃","麻仓优","羽田爱","保坂绘里"});
        addData("高中同学",new String[]{"秦始皇","李世民","武则天","曹操","刘备","孙权"});
        addData("大学同学",new String[]{"周杰伦","江一燕 ","佟丽娅","高圆圆","刘诗诗","刘亦菲","angleBaby","张静初","张含韵",});
        addData("研究生同学",new String[]{"光头强","熊大","熊二","妙蛙种子","比卡丘","双蛋瓦斯","贪吃蛇"});
        addData("博士同学",new String[]{"苍井空","小泽玛利亚","吉泽明步","波多野结衣","爱川美里菜","小川阿佐美","桃谷绘里香","泷泽萝拉","北原多香子","石川施恩惠","北条麻妃","麻仓优","羽田爱","保坂绘里"});
        addData("教授同事",new String[]{"秦始皇","李世民","武则天","曹操","刘备","孙权"});
        addData("众仙家名册",new String[]{"苍井空","小泽玛利亚","吉泽明步","波多野结衣","爱川美里菜","小川阿佐美","桃谷绘里香","泷泽萝拉","北原多香子","石川施恩惠","北条麻妃","麻仓优","羽田爱","保坂绘里","秦始皇","李世民","武则天","曹操","刘备","孙权"});
        myAdapter = new MyAdapter(this,groupList,childList);
        expandableListView.setAdapter(myAdapter);
 
    }
 
    /**
     * 用来添加数据的方法
     */
    private void addData(String group, String[] friend) {
        groupList.add(group);
        //每一个item打开又是一个不同的list集合
        List<String> childitem = new ArrayList<>();
        for (int i = 0; i < friend.length; i++) {
            childitem.add(friend[i]);
        }
        childList.add(childitem);
    }
}

然后Adapter里面需要2个item布局文件:
外层的item:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:background="#ed88ed"
    tools:context="com.duanlian.expendablelistviewdemo.MainActivity">
 
    <TextView
        android:id="@+id/group_textview"
        android:layout_width="wrap_content"
        android:layout_height="50dp"
        android:gravity="center_vertical"
        android:layout_marginLeft="40dp"
        android:textSize="20sp"
        android:text="我的好友"/>
    <TextView
        android:id="@+id/group_number"
        android:layout_width="wrap_content"
        android:layout_height="50dp"
        android:gravity="center_vertical"
        android:layout_marginRight="20dp"
        android:textSize="15sp"
        android:layout_alignParentRight="true"
        android:text="20"/>
</RelativeLayout>

里面那层item布局:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="40dp"
    tools:context="com.duanlian.expendablelistviewdemo.MainActivity">
 
    <com.duanlian.expendablelistviewdemo.CircleImageView
        android:id="@+id/child_img"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:layout_marginLeft="10dp"
        android:layout_centerVertical="true"
        android:src="@mipmap/duanlian"/>
    <TextView
        android:id="@+id/child_name"
        android:layout_height="40dp"
        android:layout_width="wrap_content"
        android:layout_toRightOf="@+id/child_img"
        android:layout_marginLeft="15dp"
        android:textSize="16sp"
        android:gravity="center_vertical"
        android:text="吉泽明步"/>
    <TextView
        android:id="@+id/child_model"
        android:layout_width="wrap_content"
        android:layout_height="40dp"
        android:gravity="center_vertical"
        android:layout_alignParentRight="true"
        android:layout_marginRight="5dp"
        android:textSize="13sp"
 
        android:text="4G"/>
</RelativeLayout>

最总要的还是在Adapter里面,他和ListView一样,也有simpleAdapter和ArrayAdapter,和BaseAdapter,我这里用的是BaseAdapter,他的adapter继承的是BaseExpandableListAdapter:

package com.example.wxpandablelistviewdemo;
import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.TextView;
import java.util.List;

/**
 * Created by duanlian on 2016/9/12.
 */
public class MyAdapter extends BaseExpandableListAdapter {
    private List<String> groupList;//外层的数据源
    private List<List<String>> childList;//里层的数据源
    private Context context;

    public MyAdapter(Context context, List<String> groupList,List<List<String>> childList ){
        this.context = context;
        this.groupList = groupList;
        this.childList = childList;
    }

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

    /**
     * 这个返回的一定要是对应外层的item里面的List集合的size
     * @param groupPosition
     * @return
     */
    @Override
    public int getChildrenCount(int groupPosition) {
        return childList.get(groupPosition).size();
    }

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

    @Override
    public Object getChild(int groupPosition, int childPosition) {
        return childList.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(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
        convertView = View.inflate(context, R.layout.item_group, null);
        //分组名字
        TextView textView = (TextView) convertView.findViewById(R.id.group_textview);
        //子元素的个数
        TextView number = (TextView) convertView.findViewById(R.id.group_number);
        number.setText(childList.get(groupPosition).size()+"个");
        textView.setText(groupList.get(groupPosition));
        return convertView;
    }

    @Override
    public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View view, ViewGroup viewGroup) {
        view = View.inflate(context, R.layout.item_child, null);
        TextView textView = (TextView) view.findViewById(R.id.child_name);
        //外层的分组名字
        textView.setText(childList.get(groupPosition).get(childPosition));
        return view;
    }

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

demo地址：https://download.csdn.net/download/heishuai123/10941739
原博客地址：https://blog.csdn.net/dl10210950/article/details/52525492