A modern programming language that makes developers happier.

kotlinlang

Screenshot 2024-01-23 at 19.29.38.png

hey everyone! :android-wave:can y'all pls help me to figure out why my `MainActivity` is blank?

• the data I need to show, is in the `NatureCardsScreen` class in the same project, and my `MainActivity` just calls this screen.
• `NatureCardsScreen`'s Previews are working perfectly fine, data is there and visible within this class.
• if I put all the code from `NatureCardsScreen` in `MainActivity`, it's not blank anymore and I can see everything.
But when I separate `NatureCardsScreen` from `MainActivity` , the activity is blank. What am I missing? (will post `MainActivity` code in the thread)

```class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            ThirtyDaysOfNatureTheme {
                Surface(
                    modifier = Modifier.fillMaxSize(),
                    color = MaterialTheme.colorScheme.background
                ) {
                    ThirtyDaysOfNature()
                }
            }
        }
    }
}

@Composable
fun ThirtyDaysOfNature() {
    NatureCardsScreen()
}```

its really simple one, the `NatureCardsScreen()` shows all the previews on its own, is there something I have to include in the `MainActivity` in this case?

Does your NatureCardsScreen take a modifier? Assuming yes.. what happens if you alter to NatureCardsScreen(modifier = Modifier.background(Color.Red)). Do you get a red background?

thank you for ur reply <@UDHEVPF4P> ! so I tried to add this Color, as you're saying, to the card - and I can see the red color in the NatureCardsScreen preview, but the MainActivity is still blank :smile:

I simplified the `NatureCardsScreen` for the sake of testing, maybe there is anything wrong/suspicious here that I'm not seeing? Here is the code:

```class NatureCardsScreen {

    @Composable
    fun NatureCard(modifier: Modifier = Modifier) {
        ElevatedCard(
            elevation = CardDefaults.cardElevation(10.dp),
            modifier = Modifier.background(Color.Red)
        ) {
            Column(
                modifier = modifier.padding(16.dp),
            ) {
                Text(text = "Some text")
                Text(text = "Some more text")
            }
        }
    }

    @Preview(showBackground = true)
    @Composable
    fun NatureCardPreview() {
        ThirtyDaysOfNatureTheme {
            NatureCard()
        }
    }
}```


NatureCardScreen is a class in your example code, not a composable and you're just creating an instance of a class in your main activity. Typically, you wouldn't need to put a composable in a class unless you had a specific reason to so you could delete the class and then use the NatureCard composable in the main activity

thank you Mike! yes, I got rid of the class, but kept composables in the separate file, and I can successfully call them from the `MainActivity` :+1: