Compose 除了可以適用在大折疊手機上,也可以 Wear OS 上跑哦 
Jetpack Compose 工具包依附元件
dependencies {
    // Standard Compose dependencies...
    // Wear specific Compose Dependencies
    implementation "androidx.wear.compose:compose-material:$rootProject.wearVersion"
    implementation "androidx.wear.compose:compose-foundation:$rootProject.wearVersion"
    // For navigation within your app...
    implementation "androidx.wear.compose:compose-navigation:$rootProject.wearVersion"
    // Other dependencies...
}

@Composable
fun WearApp(greetingName: String) {
    MyWatchTheme {
        Box(
            modifier = Modifier
                .fillMaxSize()
                .background(MaterialTheme.colors.background),
            contentAlignment = Alignment.Center
        ) {
            TimeText()
            Greeting(greetingName = greetingName)
        }
    }
}
@Composable
fun Greeting(greetingName: String) {
    Text(
        modifier = Modifier.fillMaxWidth(),
        textAlign = TextAlign.Center,
        fontSize = 24 .sp,
        color = Color.White,
        text = stringResource(R.string.hello_world,greetingName)
    )
}
Preview
@Preview(device = Devices.WEAR_OS_SMALL_ROUND, showSystemUi = true)
@Composable
fun DefaultPreview() {
    WearApp("Preview My Pixel Watch")
}

看到程式碼是不是跟app寫法一樣呢?
這樣寫完app,就可以順便 連 Wear OS 一起寫完呀