[FIXED] How to show snackbar with a button onclick in Jetpack Compose

Issue

I want to show snackbar with a button onclick in Jetpack Compose
I tried this

Button(onClick = {
    Snackbar(action = {}) {
        Text("hello")
    }
} 

But AS said "@Composable invocations can only happen from the context of a @Composable function"
Shall you give me a nice program.
I wish it can run in Button.onclick()

Solution

You'll need two things:

1. SnackbarHostState - which will manage the state of your Snackbar (you would usually get that from the ScaffoldState)
2. CoroutineScope - which will be responsible for showing your Snackbar

---

@Composable
fun SnackbarDemo() {
  val scaffoldState = rememberScaffoldState() // this contains the `SnackbarHostState`
  val coroutineScope = rememberCoroutineScope()

  Scaffold(
        modifier = Modifier,
        scaffoldState = scaffoldState // attaching `scaffoldState` to the `Scaffold`
    ) {
        Button(
            onClick = {
                coroutineScope.launch { // using the `coroutineScope` to `launch` showing the snackbar
                    // taking the `snackbarHostState` from the attached `scaffoldState`
                    val snackbarResult = scaffoldState.snackbarHostState.showSnackbar(
                        message = "This is your message",
                        actionLabel = "Do something."
                    )
                    when (snackbarResult) {
                        Dismissed -> Log.d("SnackbarDemo", "Dismissed")
                        ActionPerformed -> Log.d("SnackbarDemo", "Snackbar's button clicked")
                    }
                }
            }
        ) {
            Text(text = "A button that shows a Snackbar")
        }
    }
}

Answered By - Bartek Lipinski
Answer Checked By - David Marino (JavaFixing Volunteer)