ExpandableListView的使用，可展开的ListView

先看下效果

ExpandableListView 和LiseView类似，继承自extends ListView，布局：

<ExpandableListView
        android:id="@+id/elv"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

也需要Adapter，但是ExpandableListView 的Adapter为BaseExpandableListAdapter：

public class MyExpandAdapter extends BaseExpandableListAdapter {
    
    private Context mContext;

    public MyExpandAdapter(Context context) {
        this.mContext = context;
    }

    // 获取组的数量
    @Override
    public int getGroupCount() {
        return 10;
    }

    // 获取某一组的子条目数量
    @Override
    public int getChildrenCount(int groupPosition) {
        return 3;
    }

    // 获取组对应的对象
    @Override
    public Objects getGroup(int groupPosition) {
        return null;
    }

    // 获取某一组的某个子条目对应的对象
    @Override
    public Object getChild(int groupPosition, int childPosition) {
        return null;
    }

    // 获取组的View
    @Override
    public View getGroupView(int groupPosition, boolean isExpanded, View convertView,
            ViewGroup parent) {
        if(convertView == null) {
            convertView = new TextView(mContext);
        }
        TextView tv = (TextView) convertView;
        tv.setText("第"+groupPosition);
        return convertView;
    }

    // 获取某一组的某个子条目的View
    @Override
    public View getChildView(int groupPosition, int childPosition, boolean isLastChild,
            View convertView, ViewGroup parent) {
        if(convertView == null) {
            convertView = new TextView(mContext);
        }
        TextView tv = (TextView) convertView;
        tv.setText("第"+groupPosition+"第"+childPosition);
        return convertView;
    }

    // 某一组的某个子条目是否可点击
    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }

    // -----
    // 获取组的id
    @Override
    public long getGroupId(int groupPosition) {
        return 0;
    }

    // 获取某一组的某个子条目的id
    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return 0;
    }

    // 当数据发生变化时, id是否不变
    @Override
    public boolean hasStableIds() {
        return false;
    }

}

最后设置Adapter

mElv = (ExpandableListView) findViewById(R.id.elv);
        mElv.setAdapter(new MyExpandAdapter(this));