目前，Compose的LazyVerticalGrid DSL不支持设置spanSizeLookup。 但是，仍然可以通过编写自定义LazyItemScope并在其中使用LayoutInfo提供所需的功能。 下面是一个包含代码示例的解决方案：

@Composable
fun  LazyVerticalGridWithDynamicSpan(
    items: List,
    spanCount: Int = 2,
    itemContent: @Composable LazyItemScope.(T) -> Unit
) {
    val lazyListState = rememberLazyListState()
    val layoutInfo = remember {
        GridLayoutInfo(
            spanCount = spanCount,
        )
    }
  
    LazyVerticalGrid(
        cells = GridCells.Adaptive(minSize = 128.dp),
        state = lazyListState,
        layoutInfo = layoutInfo,
        contentPadding = PaddingValues(8.dp)
    ) {
        items(items = items) { item ->
            DynamicSpanLazyItemScope(layoutInfo) {
                itemContent(item)
            }
        }
    }
}

// 自定义LazyItemScope，用于获取当前item所占的GridItemSpan
internal class DynamicSpanLazyItemScope(
    private val layoutInfo: GridLayoutInfo,
    content: @Composable LazyItemScope.() -> Unit
) : LazyItemScope {

    private var span: Int? = null
  
    init {
        content()
        span = span ?: layoutInfo.spanCount // 如果没有设置span，则一个item占一个GridItemSpan
    }
  
    override fun Modifier.requiredWidth(): IntPx {
        return layoutInfo.cellSize * span!! + layoutInfo.horizontalGap * (span!! - 1)
    }

    override fun Modifier.requiredHeightForWidth(width: IntPx): IntPx {
        return layoutInfo.getIntrinsicHeightForWidth(width) * span!!
    }

    override fun MeasureScope.measure(
        measurable: Measurable,
        constraints: Constraints,
        layoutDirection: LayoutDirection
    ): MeasureResult {
        val itemConstraints = Constraints(
            minWidth = layoutInfo.cellSize * span!!,
            maxWidth = layoutInfo.cellSize * span!!,
            minHeight = layoutInfo.getIntrinsicHeightForWidth(constraints.maxWidth) * span!!,