android 实现A、B、C分组可点击

<?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"><ExpandableListView    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:id="@+id/elv_expandable"    ></ExpandableListView></LinearLayout>

public class ExpandableActivity extends AppCompatActivity {    @Override    protected void onCreate(@Nullable Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_expandable);       List<Map<String,String>> lm=new ArrayList<>();        List<List<Map<String,String>>> llm=new ArrayList<>();        for (int i = 0; i <3; i++) {            Map<String,String> m=new HashMap<>();            m.put("test","分组"+i);            lm.add(m);            List<Map<String,String>> l=new ArrayList<>();            for (int j = 0; j <3; j++) {                Map<String,String> h=new HashMap<>();                h.put("test","第"+i+"组第"+j+"个");                l.add(h);            }            llm.add(l);        }        SimpleExpandableListAdapter ela=new SimpleExpandableListAdapter(this,lm,android.R.layout.simple_list_item_1,new String[]{"test"},new int[]{android.R.id.text1},llm,android.R.layout.simple_list_item_1,new String[]{"test"},new int[]{android.R.id.text1});        ExpandableListView elv= (ExpandableListView) findViewById(R.id.elv_expandable);        elv.setAdapter(ela);    }}