1. 创建一个BottomSheetScaffold的实例。
2. 使用LaunchedEffect中的状态（可以根据应用选择更改的主题）。
3. 然后使用“UpdateTransition”来控制状态更改的动画，并将它们与“Modifier.height”一起使用。
4. 最后，使用“scrollState.animateScrollTo(offset)”滚动到底部弹出窗口的顶部。

示例代码：

@Composable fun BottomSheetExample() { var showBottomSheet by remember { mutableStateOf(false) } val scrollState = rememberScrollState()

BottomSheetScaffold( sheetContent = { /* Bottom sheet content */ }, sheetPeekHeight = 0.dp, scaffoldState = rememberBottomSheetScaffoldState( bottomSheetState = BottomSheetState( initialValue = BottomSheetValue.Collapsed ) ) ) { Button(onClick = { showBottomSheet = true }) { Text(text = "Open bottom sheet") }

   if (showBottomSheet) {
       LaunchedEffect(Unit) {
           with(FrameManager.defaultContext) {
               val lightTheme = true // Change this based on app preference

               UpdateTransition(lightTheme, label = "Theme").apply {
                   val isOpening = CurrentBooleanPropKey

                   targetState(switch = lightTheme)

                   val fromHeight = if (lightTheme) 600.dp else 350.dp
                   val toHeight = if (lightTheme) 350.dp else 600.dp

                   val transition = idx.transitionDefinition {
                       state(false) { this[Modifier.height] = fromHeight }
                       state(true) { this[Modifier.height] = toHeight }

                       transition(isOpening to true) {
                           Modifier.height using tween(
                               durationMillis = 500
                           )
                       }

                       transition(isOpening to false) {
                           Modifier.height using tween(
                               durationMillis = 500
                           )
                       }
                   }

                   val state = AnimState(false)
                   snapshotFlow { state.value }

                   val endState = transition.createAnimationState(
                       targetValue = switch,
                       onStateChangeFinished = {
                           state.value = switch
                       }