ExpandableListView 可折叠的下拉listview

ExpandableListView用法如下

1.定义布局文件main.xml文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ExpandableListView
        android:childIndicator="@drawable/icon"
        android:id="@+id/el"
        android:layout_width="match_parent"
        android:layout_height="match_parent" >
    </ExpandableListView>

</LinearLayout>

2.java代码如下

public class MainActivity extends Activity {

    final int[] images = { R.drawable.p, R.drawable.t, R.drawable.z };
    final String[] names = { "人族", "虫族", "神族" };
    final String[][] names_ = { { "特种兵", "警察", "城管" }, { "蚂蚁", "蚯蚓", "蜘蛛" },
            { "大神", "玉皇大帝", "如来佛祖" } };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.test);
        ExpandableListView el = (ExpandableListView) findViewById(R.id.el);
        //此处使用ExpandableListAdapter的子类BaseExpandableListAdapter,否则使用父类会有很多方法需要重写
        el.setAdapter(new BaseExpandableListAdapter() {
            @Override
            public boolean isChildSelectable(int groupPosition,
                    int childPosition) {
                return true;
            }

            @Override
            public boolean hasStableIds() {
                return true;
            }
            //自定义一个方法,用于操作 父级/子级菜单中的文本
            private TextView getTextView() {
                AbsListView.LayoutParams param = new AbsListView.LayoutParams(
                        ViewGroup.LayoutParams.WRAP_CONTENT, 66);//定义列表每行的宽度以及高度
                TextView tv = new TextView(MainActivity.this);
                tv.setLayoutParams(param);
                tv.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);//定义文本位置
                tv.setPadding(60, 0, 0, 0);//居左60dp
                tv.setTextSize(24);
                return tv;
            }

            //获取父级视图--把图片和文本挂载到 线性布局上
            @Override
            public View getGroupView(int groupPosition, boolean isExpanded,
                    View convertView, ViewGroup parent) {
                LinearLayout ll = new LinearLayout(MainActivity.this);
                ll.setOrientation(0);
                ImageView iv = new ImageView(MainActivity.this);
                iv.setImageResource(images[groupPosition]);
                ll.addView(iv);

                TextView tv = getTextView();
                tv.setText(getGroup(groupPosition).toString());
                ll.addView(tv);
                return ll;
            }

            @Override
            public long getGroupId(int groupPosition) {
                return groupPosition;
            }
            //获取父级菜单数量
            @Override
            public int getGroupCount() {
                return names.length;
            }

            //获取每个父级对象
            @Override
            public Object getGroup(int groupPosition) {
                return names[groupPosition];
            }
            //获取下拉子菜单的数量
            @Override
            public int getChildrenCount(int groupPosition) {
                return names_[groupPosition].length;
            }
            //显示下拉菜单项
            @Override
            public View getChildView(int groupPosition, int childPosition,
                    boolean isLastChild, View convertView, ViewGroup parent) {
                TextView tv = getTextView();
                tv.setText(getChild(groupPosition, childPosition).toString());
                return tv;
            }
            //获取下拉子菜单的id
            @Override
            public long getChildId(int groupPosition, int childPosition) {
                return childPosition;
            }

            //获取下拉子菜单中的 每个对象
            @Override
            public Object getChild(int groupPosition, int childPosition) {
                return names_[groupPosition][childPosition];
            }
        });
    }