Android 如何在 compose 中使用 BottomSheetScaffold 为底页设置半展开高度

发布于10月12日

我需要先在折叠状态下露出我的底单.而在向上滑动底纸时，它应该首先固定在屏幕的一半高度.再次向上滑动时，它应该扩展到屏幕的最大高度.在倒塌过程中也是如此.首先从最大高度到半高，然后到窥视高度(折叠状态下可见的底片高度).有没有办法使用BottomSheetScaffold实现这一点？

推荐答案

我开始为你写那个解决方案.你可以美化它

enum class ExpandedType {
    HALF, FULL, COLLAPSED
}

  @Composable
private fun BottomSheet() {
    val configuration = LocalConfiguration.current
    val screenHeight = configuration.screenHeightDp
    var expandedType by remember {
        mutableStateOf(ExpandedType.COLLAPSED)
    }
    val height by animateIntAsState(
        when (expandedType) {
            ExpandedType.HALF -> screenHeight / 2
            ExpandedType.FULL -> screenHeight
            ExpandedType.COLLAPSED -> 70
        }
    )
    val bottomSheetScaffoldState = rememberBottomSheetScaffoldState(
        bottomSheetState = BottomSheetState(BottomSheetValue.Collapsed)
    )
    BottomSheetScaffold(
        scaffoldState = bottomSheetScaffoldState,
        sheetElevation = 8.dp,
        sheetShape = RoundedCornerShape(
            bottomStart = 0.dp,
            bottomEnd = 0.dp,
            topStart = 12.dp,
            topEnd = 12.dp
        ),
        sheetContent = {
            var isUpdated = false
            Box(
                Modifier
                    .fillMaxWidth()
                    .height(height.dp)
                    .pointerInput(Unit) {
                        detectVerticalDragGestures(
                            onVerticalDrag = { change, dragAmount ->
                                change.consume()
                                if (!isUpdated) {
                                    expandedType = when {
                                        dragAmount < 0 && expandedType == ExpandedType.COLLAPSED -> {
                                            ExpandedType.HALF
                                        }
                                        dragAmount < 0 && expandedType == ExpandedType.HALF -> {
                                            ExpandedType.FULL
                                        }
                                        dragAmount > 0 && expandedType == ExpandedType.FULL -> {
                                            ExpandedType.HALF
                                        }
                                        dragAmount > 0 && expandedType == ExpandedType.HALF -> {
                                            ExpandedType.COLLAPSED
                                        }
                                        else -> {
                                            ExpandedType.FULL
                                        }
                                    }
                                    isUpdated = true
                                }
                            },
                            onDragEnd = {
                                isUpdated = false
                            }
                        )
                    }
                    .background(Color.Red)
            )
        },
        sheetPeekHeight = height.dp
    ) {
        Box(
            Modifier
                .fillMaxSize()
                .background(Color.Black)
        )
    }
}