Question

我使用UserDefault保存字典

当我打印出UserDefault时会出现以下结果

Optional({
Hamburger =     {
    count = 1;
    subtotal = 70;
};

Cake =     {
    count = 1;
    subtotal = 80;
};

Steak =     {
    count = 1;
    subtotal = 90;
  };

})

我的问题是我只能删除汉堡包这样的钥匙之一吗？

保留其余两个项目

仅删除所有UserDefault，

仅删除指定的项目

Answer 1

您可以从UserDefaults获取字典，然后可以删除所需的键/对象。然后可以将更新对象再次存储到UserDefault中。

       let kUserDefault = UserDefaults.standard

       let object = kUserDefault.object(forKey: "StoredValue") as! NSDictionary
        let storedValue = NSMutableDictionary.init(dictionary:object)
        storedValue.removeObject(forKey: "Hamburger")
        print(storedValue)

        kUserDefault.set(storedValue, forKey: "StoredValue")
        kUserDefault.synchronize()

        let newObject : NSMutableDictionary = kUserDefault.object(forKey: "StoredValue") as! NSMutableDictionary
        print(newObject)

Answer 2

找到此解决方案：

    // To remove required value from dictionary
    let userDefault = UserDefaults.standard
    if var storedDictionary = userDefault.object(forKey: "StoredDictionary") as? [String: Any] {
        storedDictionary.removeValue(forKey: "Hamburger")
        userDefault.setValue(storedDictionary, forKey: "StoredDictionary")
    }

    // To fetch updated value again wherer you want.
    if let storedDictionary = userDefault.object(forKey: "StoredDictionary") as? [String: Any] {
        print("StoredDictionary: ", storedDictionary)
    }

我只能在Swift中删除UserDefaults项之一吗？

2 个答案: