安卓开发 ExpandableListView 使用示例

好的，您想了解安卓开发 ExpandableListView 的使用示例，以下是一个简单的示例：

1. 定义适配器类

public class ExpandableListAdapter extends BaseExpandableListAdapter {

    private Context mContext;
    private List<String> mGroupTitles; // 父分组数据
    private HashMap<String, List<String>> mChildData; // 子分组数据

    public ExpandableListAdapter(Context context, List<String> groupTitles, HashMap<String, List<String>> childData) {
        mContext = context;
        mGroupTitles = groupTitles;
        mChildData = childData;
    }

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

    @Override
    public int getChildrenCount(int groupPosition) {
        return mChildData.get(mGroupTitles.get(groupPosition)).size();
    }

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

    @Override
    public Object getChild(int groupPosition, int childPosition) {
        return mChildData.get(mGroupTitles.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) {
        LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View view = inflater.inflate(R.layout.list_item_group, null);

        TextView title = (TextView) view.findViewById(R.id.group_title);
        title.setText(mGroupTitles.get(groupPosition));

        return view;
    }

    @Override
    public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
        LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View view = inflater.inflate(R.layout.list_item_child, null);

        TextView title = (TextView) view.findViewById(R.id.child_title);
        title.setText(mChildData.get(mGroupTitles.get(groupPosition)).get(childPosition));

        return view;
    }

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

2. 定义布局文件

list_item_group.xml

<?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="wrap_content"
    android:orientation="vertical"
    android:paddingLeft="40dp"
    android:paddingRight="40dp"
    android:paddingTop="20dp"
    android:paddingBottom="20dp">

    <TextView
        android:id="@+id/group_title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="18sp" />

</LinearLayout>

list_item_child.xml

<?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="wrap_content"
    android:orientation="vertical"
    android:paddingLeft="40dp"
    android:paddingRight="40dp"
    android:paddingTop="15dp"
    android:paddingBottom="15dp">

    <TextView
        android:id="@+id/child_title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="16sp" />

</LinearLayout>

3. 在 Activity 中使用 ExpandableListView

public class MainActivity extends AppCompatActivity {

    private ExpandableListView mExpandableListView;
    private ExpandableListAdapter mAdapter;
    private List<String> mGroupTitles;
    private HashMap<String, List<String>> mChildData;

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

        // 初始化数据
        initData();

        // 初始化 ExpandableListView
        mExpandableListView = (ExpandableListView) findViewById(R.id.expandable_list_view);
        mAdapter = new ExpandableListAdapter(this, mGroupTitles, mChildData);
        mExpandableListView.setAdapter(mAdapter);

        // 设置子项点击监听器
        mExpandableListView.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
            @Override
            public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {
                Toast.makeText(MainActivity.this, "您点击了" + mChildData.get(mGroupTitles.get(groupPosition)).get(childPosition), Toast.LENGTH_SHORT).show();
                return true;
            }
        });
    }

    private void initData() {
        mGroupTitles = new ArrayList<>();
        mGroupTitles.add("计算机");
        mGroupTitles.add("自然科学");
        mGroupTitles.add("哲学");

        List<String> computers = new ArrayList<>();
        computers.add("Java");
        computers.add("Python");
        computers.add("C++");
        computers.add("PHP");
        computers.add("JavaScript");
        computers.add("HTML/CSS");
        computers.add("SQL");

        List<String> sciences = new ArrayList<>();
        sciences.add("物理");
        sciences.add("化学");
        sciences.add("生物");
        sciences.add("地理");
        sciences.add("天文");

        List<String> philosophies = new ArrayList<>();
        philosophies.add("伦理学");
        philosophies.add("形而上学");
        philosophies.add("认识论");
        philosophies.add("逻辑学");
        philosophies.add("美学");

        mChildData = new HashMap<>();
        mChildData.put(mGroupTitles.get(0), computers);
        mChildData.put(mGroupTitles.get(1), sciences);
        mChildData.put(mGroupTitles.get(2), philosophies);
    }
}

这样，您就可以展示一个带父分组和子分组的 ExpandableListView ，同时设置子项点击监听器，实现相应的功能了。