MainActivity.kt

// Compose -> XML

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            DefaultTheme {
                // A surface container using the 'background' color from the theme
                Surface(
                    modifier = Modifier.fillMaxSize(),
                    color = MaterialTheme.colorScheme.background
                ) {
                    Greeting("Android")
                }
            }
        }
    }
}

@Composable
fun Greeting(name: String, modifier: Modifier = Modifier) {

    val context = LocalContext.current

    Text(
        text = "Hello $name!",
        modifier = modifier.clickable {
            val intent = Intent(context, HappyActivity::class.java)
            context.startActivity(intent)
        }
    )
}

@Preview(showBackground = true)
@Composable
fun GreetingPreview() {
    DefaultTheme {
        Greeting("Android")
    }
}

activity_happy.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="<http://schemas.android.com/apk/res/android>"
    xmlns:app="<http://schemas.android.com/apk/res-auto>"
    xmlns:tools="<http://schemas.android.com/tools>"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".HappyActivity">

    <TextView
        android:text="강의를 들으시는\\n여러분이 챔피언"
        android:textSize="50sp"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</androidx.constraintlayout.widget.ConstraintLayout>

AndroidManifest.xml

<activity
  android:name=".HappyActivity"
  android:exported="false"
  android:theme="@style/Theme.AppCompat.Light"/>