Hi, why i can't receive any notification when state changed like this: ```data class Question(var ad...

# compose

[Nana Vong]

Hi, why i can't receive any notification when state changed like this:

data class Question(var add: Boolean = true)

val testState = MutableLiveData<List<Question>>()
testState.value = listOf(Question(false))
val state = testState.observeAsState()
RedButton(
    text = state.value?.get(0)?.add?.toString() ?: "?",
    btnColor = Color.Red,
    modifier = Modifier.clickable {
        testState.value = testState.value.apply {
            this?.get(0)?.add = true
        }
    })

[Luke]

I guess you should use “by” keyword 🙂

[Nana Vong]

"by" just a delegator ,the reason not this

[Albert Chang]

Standard properties don't magically become observable in compose. I would suggest you make your data class immutable (data class Question(val add: Boolean = true)) and use a mutableStateListOf<Question>(). Then you update the item like this: list[0] = Question(add = false).

[Albert Chang]

This post may help you understand.