A composable function does not work in timer.ontick-CodePudding

I'm new to jetpack compose and I have created a composable function with a simple text. I would like to update it every time a timer reaches timer.ontick function but it does not work. Any help?

fun LKIDView(text : String, onLKIDViewChange: (String) -> Unit) {

  var lkidState by remember { mutableStateOf("Default") }
    val onlkidChange={text : String -> lkidState = text}

    Column(
        horizontalAlignment = Alignment.CenterHorizontally, modifier = Modifier
            .fillMaxWidth()
            .background(Color(0xFF7DCEA0))
    ) {

        Text(
          text = lkidState,

            // modifier = Modifier.fillMaxWidth(),
            fontSize = 20.sp,
            fontWeight = FontWeight.Bold,
            fontFamily = FontFamily.SansSerif,
            //
        )
    }
}`
`
My ontimer.tick looks like this

`val timer = object : CountDownTimer(Gtime, Ttime) {

         var lkidviewState = remember { mutableStateOf("Landkreis/Kreeisfreie Stadt") }
          val onTextChange={text : String -> lkidviewState.value = text}

        override fun onTick(millisUntilFinished: Long) {
            Log.e("TimerTick - ", "Tick ")
            LKIDView(text =lkidviewState.value , onLKIDViewChange = onTextChange)
           // lkidviewState.value = "dsfdsfdsf"`}`

Android Studio says composable invocation can only happen from the context of a composable function

timer runs - the code did not update the ui

CodePudding user response：

Compose doesn't work in this way.

You can't call a composable inside the CountDownTimer to display the updated value.
Instead you have to use a state (lkidState), and then CountDownTimer has to update this value.

val lkidState = remember {
    mutableStateOf(0)
}

val timer = object : CountDownTimer(0, 1000) {

    override fun onTick(millisUntilFinished: Long) {
        lkidState.value = millisUntilFinished
    }

    //...
}

Text(text = lkidState.value.toString())

Final note, I would use other option instead of a CountDownTimer, like a side effect.