Android LiveData/StateFlow 列表项属性更新问题

Question

所以我正在更新我的RecylerView与 StateFlow<List>如下所示:
我的数据类:

data class Student(val name: String, var isSelected: Boolean)

我的 ViewModel 逻辑:

fun updateStudentsOnSelectionChanged(targetStudent: Student) {
    val targetIndex = _students.value.indexOf(targetStudent)
    val isSelected = !targetStudent.isSelected

    _students.value[targetIndex].isSelected = isSelected        //<- doesn't work
} 

问题: UI 没有改变，但 isSelected里面 _student变了，怎么回事？ (与 LiveData 相同)

Answer 1

我假设 _students是 StateFlow<List> .更改 isSelected Student 的属性(property)模型不会触发 StateFlow .解决方法是使 isSelected Student 的属性(property)数据类不可变以在设置新状态时对其进行比较，创建 MutableList退出当前列表并复制现有的Student具有 isSelected 新值的对象属性(property):

data class Student(val name: String, val isSelected: Boolean)

val students = _students.value.toMutableList()
students[targetIndex] = students[targetIndex].copy(isSelected = isSelected)
_students.value = students