Android选择框怎么实现分组功能

要实现 Android 选择框的分组功能，可以使用 ExpandableListView 控件来展示分组列表，并在每个分组下面展示可选择的子项。

首先，在布局文件中添加 ExpandableListView 控件：

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

然后，创建一个适配器类来管理分组和子项的数据，并绑定到 ExpandableListView 控件上：

public class MyExpandableListAdapter extends BaseExpandableListAdapter {          private Context context;     private List<String> groups;     private Map<String, List<String>> items;      public MyExpandableListAdapter(Context context, List<String> groups, Map<String, List<String>> items) {         this.context = context;         this.groups = groups;         this.items = items;     }      @Override     public int getGroupCount() {         return groups.size();     }      @Override     public int getChildrenCount(int groupPosition) {         return items.get(groups.get(groupPosition)).size();     }      @Override     public Object getGroup(int groupPosition) {         return groups.get(groupPosition);     }      @Override     public Object getChild(int groupPosition, int childPosition) {         return items.get(groups.get(groupPosition)).get(childPosition);     }      @Override     public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {         // Implement how to display group view     }      @Override     public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {         // Implement how to display child view     }      @Override     public boolean isChildSelectable(int groupPosition, int childPosition) {         return true;     }      @Override     public boolean hasStableIds() {         return false;     }      // Other required methods } 

在 getGroupView 和 getChildView 方法中实现如何展示分组和子项的视图。

最后，在 Activity 或 Fragment 中设置 ExpandableListView 控件和适配器：

ExpandableListView expandableListView = findViewById(R.id.expandableListView); List<String> groups = new ArrayList<>(); groups.add("Group 1"); groups.add("Group 2");  Map<String, List<String>> items = new HashMap<>(); List<String> group1Items = new ArrayList<>(); group1Items.add("Item 1"); group1Items.add("Item 2"); items.put("Group 1", group1Items);  List<String> group2Items = new ArrayList<>(); group2Items.add("Item A"); group2Items.add("Item B"); items.put("Group 2", group2Items);  MyExpandableListAdapter adapter = new MyExpandableListAdapter(this, groups, items); expandableListView.setAdapter(adapter); 

这样就可以实现一个具有分组功能的选择框。