'_InternalLinkedHashMap <String，dynamic>'类型不是'Map <String，int>'类型的子类型

Question

我正在尝试将地图保存为共享的首选项并重新加载，我在保存时对地图进行编码，在加载时进行解码，但是我无法将解码json的值设置回我保存的原始地图，我的json解码返回的数据是什么？

 Map<String, int> purchasedItems =  {Sweet Pepper: 0, Lemon: 0, Eggplants: 0, Colorful Pepper: 0, Kiwi: 0, Fava Bean: 0, GrapeLeaf dolma: 0, Potatoes: 0, Spicy Pepper: 0, Grapefruit: 0, Tomatoes: 0, Cherries: 0, Red raddish: 0, Carrots: 0, Dolma: 0};
 Map<String, int> savedPurchasedItems = {};

void savePurchasesPrefs(Map<String, int> purchasedItems) async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    var something = jsonEncode(purchasedItems);
    var savePurchases = prefs.setString("savedPurchasedItems", something);
    print("saved purchases prefs $savePurchases");
  }

  void loadPurchasesPrefs() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    var something = await prefs.get("savedPurchasedItems");
    print("loaded items: $something");
    var yee = jsonDecode(something);
    purchasedItems = yee;
    print("yee : $yee");
  }

Answer 1

通过将purchaseItems的类型更改为“到处映射”来修复它，并且效果很好。