Question

我已从JSON解析了一些PHP数据，并将其显示为Spinner。数据附带Key-Value。所以我将Hashmap与SimpleAdapter一起使用。 Spinner仅显示值。当用户选择一个项目时，该密钥将存储在MySQL。

中

这是我的JSON，

{
    "32":"Western Food",
    "33":"Chinese Food",
    "34":"Mix Food",
    "35":"Japanese Food",
    "36":"Korean Food",
    "37":"Italian Food",
    "38":"German Food",
    "45":"Muslim food ",
    "46":"Indian food"
}

例如

活动A

用户添加新类别，他们选择＆＃34; Mix Food＆＃34;。当他们点击提交按钮时，键 - ＆＃34; 34＆＃34;将存储在数据库中。

活动B

int get_selected_item_id=34;

List<HashMap<String, String>> category_arraylist = new ArrayList<HashMap<String, String>>();
Iterator<String> iterator = jsonObject1.keys();
    while (iterator.hasNext()) {

        String id = iterator.next();
        String name=jsonObject1.getString(id);
        HashMap<String, String> map = new HashMap<>();
        map.put("id",id);
        map.put("name",name);
        category_arraylist.add(map);

    }

    String[] from = {"name"};
    int[] to = {android.R.id.text1};
    final SimpleAdapter adapter = new SimpleAdapter(item_edit.this, category_arraylist, android.R.layout.simple_spinner_dropdown_item, from, to);
    category.setAdapter(adapter);

    category.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
            category.setSelection(get_selected_item_id); // doesn't work
        }

        @Override
        public void onNothingSelected(AdapterView<?> adapterView) {

        }
    });

如果在微调器开始显示时，如何在活动B中将此项显示为默认值？

Answer 1

为您的JSON数据

创建一个模型类

private class Item {
    String key;
    String value;

    public Item(String key, String value) {
        this.key = key;
        this.value = value;
    }

    public String getKey() {
        return key;
    }

    public void setKey(String key) {
        this.key = key;
    }

    public String getValue() {
        return value;
    }

    public void setValue(String value) {
        this.value = value;
    }

    @Override
    public String toString() {
        return value;
    }
}

将您的数据解析为此模型类

List<Item> list = new ArrayList<>();
Iterator<String> iterator = jsonObject1.keys();
while (iterator.hasNext()) {
    String id = iterator.next();
    String name = jsonObject1.getString(id);
    list.add(new Item(id, name));
}

初始化Spinner，

final ArrayAdapter<Item> adapter = new ArrayAdapter<Item>(this, android.R.layout.simple_spinner_dropdown_item, list);
category.setAdapter(adapter);

在get_selected_item_id中找到list的索引，并使用setSelection的{{1}}方法将其设置为默认值。

Spinner

int index = findIndexOf(list, get_selected_item_id); if (index != -1) { category.setSelection(index); }方法，

findIndexOf

private int findIndexOf(List<Item> list, int selectedKey) { for (int i = 0; i < list.size(); i++) { if (list.get(i).getKey().equals(String.valueOf(selectedKey))) { return i; } } return -1; }，

ItemSelectedListener

Android设置默认值来自简单适配器中的Spinner的Hashmap键

1 个答案: