When Modify a Value in the Copied List, It Modify the Value in The Original List Flutter - list

Question

I want to copy list and make no reference even when I edit value in copied list. I tried addAll(), List.from(), map(), toList() and [...myList] but they were unhelpful.
Edit for Clarification
Ex:
class Item{
String description;
int price;
Item(this.description, this.price);
}
List<Item> items = [
Item('item 1', 100),
Item('item 2', 200),
Item('item 3', 300),
];
List<Item> selectedItems = List.from(items);
When I edit selectedItems original list items shouldn't be affected, but it's not?!
selectedItems[0].price = 115;
it modifies the price of element 0 in both.

Answer 1

Flutter haven't copy function for objects, you should create "copy constructor" manually. It's discussed here: How can I clone an Object (deep copy) in Dart?
Solution for your example:
void main() {
// Original list
List<Item> items = [
Item('item 1', 100),
Item('item 2', 200),
Item('item 3', 300),
];
// Copied list
List<Item> selectedItems = items.map((it) => Item.copy(it)).toList();
// Change price for item in copied list
selectedItems[0].price = 115;
print("Original list:");
items.forEach((it) => print("Description: ${it.description}, price: ${it.price}"));
print("Copied list:");
selectedItems.forEach((it) => print("Description: ${it.description}, price: ${it.price}"));
}
class Item {
String description;
int price;
Item(this.description, this.price);
// Copied constructor
Item.copy(Item item) : this(item.description, item.price);
}