android – Kotlin中带有对象的列表的深层副本

class ClassA(var title: String?,var list: ArrayList<ClassB>,var SELEcted: Boolean)
class ClassB(val id: Int,val name: String)

val oldList:ArrayList<ClassA>


val newList :ArrayList<ClassA> = ArrayList()
newList.addAll(oldList)

这是因为您将所有对象引用添加到另一个列表,因此您没有制作正确的副本,您在两个列表中具有相同的元素.如果需要diferents列表和不同的引用,则必须克隆新列表中的每个对象：

public data class Person(var n: String)

fun main(args: Array<String>) {
    //creates two instances
    var Anna = Person("Anna")
    var Alex =Person("Alex")

    //add to list
    val names = arrayOf(Anna,AleX)
    //generate a new real clone list
    val clonenames = names.map{it.copy()}

    //modify first list
    clonenames.get(0).n = "Another Anna clone"

    println(names.toList())
    println(clonenames.toList())
}

[Person(n=Anna),Person(n=AleX)]
[Person(n=Another Anna clonE),Person(n=AleX)]