尝试保存数组时出现错误-无法将类型[Data]的值转换为预期的参数类型&#39;[Dictionary <String, AnyObject> ]”

Question

I'm trying to save array added from tableview using this function:

class func saveArray(_ value: [Dictionary<String, AnyObject>], key: String) {
        let data = NSKeyedArchiver.archivedData(withRootObject: value)
        UserDefaults.standard.set(data, forKey: key)
    }

Below is the function where I want to save the array:

func addItemCat(items: [Data]) {
        print("ITEM: ", items)
        dataSource.myListTableViewController.myListArr = items
        self.myListTV.isHidden = false
        UserDefaultsHelper.saveArray(items, key: Constants.myList.myList)
    }

However, I got this error: Cannot convert value of type '[Data]' to expected argument type '[Dictionary String, AnyObject ]'

Below is my Data model: data model screencap

I'm new to Swift and I hope someone can explain what is the problem.

Answer 1

Problem is with data types, saveArray function expects value parameter of type array of dictionary [Dictionary<String, AnyObject>] , but you are passing array of data model objects which is a type-mismatch error.

To solve this:

First, You should not use pre-defined keywords for creating your custom object. Use DataObject instead:

struct DataObject {

}

Now change your saveArray function as:

class func saveArray(_ value: [DataObject], key: String) {
    let data = NSKeyedArchiver.archivedData(withRootObject: value)
    UserDefaults.standard.set(data, forKey: key)
}

and addItemCat , function as:

func addItemCat(items: [DataObject]) {
    print("ITEM: ", items)
    dataSource.myListTableViewController.myListArr = items
    self.myListTV.isHidden = false
    UserDefaultsHelper.saveArray(items, key: Constants.myList.myList)
}