ExpandableListView控件实现二级列表

效果图如下：

二级列表附有点击事件。

1、布局文件：

此处加了一个自定义的导航RelativeLayout，记得注activity的时候添加 android:theme="@style/Theme.AppCompat.Light.NoActionBar" 去掉自带的导航。

 <?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="match_parent">

     <RelativeLayout
         android:layout_width="match_parent"
         android:layout_height="@dimen/dimen_55"
         android:background="@color/main_title"
         >
         <TextView
             android:layout_centerVertical="true"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="取消"
             android:textColor="@color/white"
             android:textSize="@dimen/dimen_18"
             android:layout_marginLeft="@dimen/dimen_13"
             android:onClick="goBack"
             />
         <TextView
             android:layout_centerVertical="true"
             android:layout_centerHorizontal="true"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="安卓二级列表"
             android:textColor="@color/white"
             android:textSize="@dimen/dimen_18"/>
     </RelativeLayout>

     <!--二级菜单-->
     <ExpandableListView
         android:id="@+id/expandableListView"
         android:layout_width="match_parent"
         android:layout_height="wrap_content">
     </ExpandableListView>

 </LinearLayout>

2、一级列表布局：

ImageView是用来自定义打开闭合图标的（不自定义也可以，箭头会默认在最左边），建议自己用一个ImageView控件来控制上下箭头。图标可以去阿里巴巴矢量图上下载。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal" android:layout_width="match_parent"
    android:layout_height="wrap_content">
<!--一级列表 item布局-->

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <TextView
            android:id="@+id/tv_group"
            android:layout_width="wrap_content"
            android:layout_height="30dp"
            android:gravity="center"
            android:text="group text"
            />
        <ImageView
            android:id="@+id/iv_group"
            android:layout_alignParentRight="true"
            android:layout_centerVertical="true"
            android:layout_marginRight="@dimen/dimen_20"
            android:layout_width="20dp"
            android:layout_height="20dp" />
    </RelativeLayout>

</LinearLayout>

3、二级列表布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal" android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center">
<!--二级列表 item布局-->

    <ImageView
        android:id="@+id/iv_child"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:src="@mipmap/ic_launcher" />
    <TextView
        android:id="@+id/tv_child"
        android:layout_marginLeft="@dimen/dimen_20"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="item text" />

</LinearLayout>

4、activity代码：

     private ExpandableListView expandableListView;

     //一级列表数据源
     private String[] groups = {"软件设计", "数据库技术", "操作系统"};
     //二级列表数据源
     private String[][] childs={{"架构设计","面向对象","设计模式","领域驱动设计"},{"SQL Server","Oracle","MySql", "Dameng "},{"Linux","Windows","嵌入式"}};

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

         initView();
     }
     private void initView() {
         expandableListView = (ExpandableListView)findViewById(R.id.expandableListView);
         //#TODO 去掉自带箭头，在一级列表中动态添加
         expandableListView.setGroupIndicator(null);
         expandableListView.setAdapter(new MyExpandableListView());

     }
     public void goBack(View view) {
         finish();
     }

5、ExpandableListView适配器：

继承自BaseExpandableListAdapter，重写ExpandableListAdapter中的10个方法

 class MyExpandableListView extends BaseExpandableListAdapter {

         /*一级列表个数*/
         @Override
         public int getGroupCount() {
             return groups.length;
         }

         /*每个二级列表的个数*/
         @Override
         public int getChildrenCount(int groupPosition) {
             return childs[groupPosition].length;
         }

         /*一级列表中单个item*/
         @Override
         public Object getGroup(int groupPosition) {
             return groups[groupPosition];
         }

         /*二级列表中单个item*/
         @Override
         public Object getChild(int groupPosition, int childPosition) {
             return childs[groupPosition][childPosition];
         }

         @Override
         public long getGroupId(int groupPosition) {
             return groupPosition;
         }

         @Override
         public long getChildId(int groupPosition, int childPosition) {
             return childPosition;
         }

         /*每个item的id是否固定，一般为true*/
         @Override
         public boolean hasStableIds() {
             return true;
         }

         /*#TODO 填充一级列表
         * isExpanded 是否已经展开
         * */
         @Override
         public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
             if (convertView == null) {
                 convertView = getLayoutInflater().inflate(R.layout.list_item_expandablelistview,null);
             }
             TextView tv_group = (TextView) convertView.findViewById(R.id.tv_group);
             ImageView iv_group = (ImageView) convertView.findViewById(R.id.iv_group);
             tv_group.setText(groups[groupPosition]);
             //控制是否展开图标
             if (isExpanded) {
                 iv_group.setImageResource(R.drawable.expand_iv_up);
             } else {
                 iv_group.setImageResource(R.drawable.expand_iv_down);
             }
             return convertView;
         }

         /*#TODO 填充二级列表*/
         @Override
         public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
             if (convertView == null) {
                 convertView = getLayoutInflater().inflate(R.layout.list_item_expandablelistview_child,null);
             }
             ImageView image = (ImageView) convertView.findViewById(R.id.iv_child);
             TextView tv = (TextView) convertView.findViewById(R.id.tv_child);
             tv.setText(childs[groupPosition][childPosition]);
             return convertView;
         }

         /*二级列表中每个能否被选中，如果有点击事件一定要设为true*/
         @Override
         public boolean isChildSelectable(int groupPosition, int childPosition) {
             return true;
         }

     }

到这里基本就完成了，最后再配置一下每个二级列表的点击事件即可：

 expandableListView.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
             @Override
             public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {
                 TextView childAt = (TextView)((LinearLayout) v).getChildAt(1);//获得点击列表中TextView的值，需要强转一下，否则找不到getChildAt方法
5                 Toast.makeText(ExpandableListViewActivity.this, "点击了 "+childAt.getText()+" 列表", Toast.LENGTH_SHORT).show(); 

                 return true; 

              } 
  });