arraylist - 将Array 转换为ArrayList

Question

如何在Kotlin中将Array<String>转换为ArrayList<String>？

var categoryList : ArrayList<String>?=null
val list = arrayOf("None", "ABC")
categoryList = ArrayList(Arrays.asList(list))

我收到此错误:

错误

Type inference failed. Expected type mismatch: inferred type is kotlin.collections.ArrayList<Array<String>!> /* = java.util.ArrayList<Array<String>!> */ but kotlin.collections.ArrayList<String>? /* = java.util.ArrayList<String>? */ was expected

Answer 1

您可能对 toCollection 感兴趣，以便将元素添加到您传递的任何集合中:

categoryList = list.toCollection(ArrayList())

请注意，要解决您的特定问题，您只需要 spread operator ( * )即可。使用 * -fix，它也可以工作:

categoryList = ArrayList(Arrays.asList(*list))