如何在ListDetailPaneScaffold详情面板显示未选中占位内容？

你只需要调整detailPane的逻辑，不再依赖navigator.currentDestination?.content控制Map的渲染时机，改为始终渲染Map组件，根据是否有选中项传入对应参数即可：

ListDetailPaneScaffold(
    modifier = Modifier.fillMaxSize(),
    directive = navigator.scaffoldDirective,
    value = navigator.scaffoldValue,
    listPane = {
        AnimatedPane(modifier = Modifier.fillMaxWidth(0.1f)) {
            LinesList(
                lines = uiState.lines,
                selectedIndex = uiState.lines.indexOf(uiState.selectedLine),
                onItemClick = { index ->
                    navigator.navigateTo(ListDetailPaneScaffoldRole.Detail, index)
                },
            )
        }
    },
    detailPane = {
        AnimatedPane {
            // 始终渲染Map，根据是否有选中项传入对应数据
            val selectedLine = navigator.currentDestination?.content?.let { index ->
                uiState.lines[index].also { vm.selectLine(it) }
            }
            Map(selectedItem = selectedLine)
        }
    },
)

最后需要确保你的Map组件支持接收null类型的selectedItem，当selectedItem为null时，仅加载基础空白地图、不绘制路线即可。

内容的提问来源于stack exchange，提问作者NullPointerException