Android ExpandableListview 如何用循环把 组和子元素展示出来

Question

以下代码只是一个例子把组合子元素展示出来。 如果我连接去数据库的话， 这种方法显然行不通。因为我们无法确定有多少个组合多少个子。 大神们可否指点一下如何用 循环把它们展示出来？ 例如用 For 循环。

adapter adapter; // BaseExpandableListAdapter
ExpandableListView expandableListView;
List<String> category;
HashMap<String,List<String>> item;

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

    expandableListView=(ExpandableListView)findViewById(R.id.listview);
    display();
    adapter=new adapter(this,category,item);
    expandableListView.setAdapter(adapter);

}

public void display(){

    category=new ArrayList<String>();
    item=new HashMap<String,List<String>>();

    category.add("Western Food");
    category.add("Chinese Food");
    category.add("Japanese Food");

    List<String> western_food = new ArrayList<String>();
    western_food.add("Fried Chicken");
    western_food.add("French Fries");
    western_food.add("Beef Steak");

    List<String> chinese_food = new ArrayList<String>();
    chinese_food.add("Chicken Rice");
    chinese_food.add("Duck Rice");

    List<String> japanese_food = new ArrayList<String>();
    japanese_food.add("Tapanyaki");
    japanese_food.add("Takoyagi");
    japanese_food.add("Sushi");
    japanese_food.add("Lamian");

    item.put(category.get(0), western_food);
    item.put(category.get(1), chinese_food);
    item.put(category.get(2), japanese_food);

}

Answer 1

You don’t need to know how many combinations and sub-groups there are, as long as you can distinguish the combinations to which different combinations and sub-groups belong from the data obtained from the database. Put the data into the corresponding storage collection and display it through the design Adapter.