Android 如何在 Jetpack Compose 中将 NavigationRail 的内容居中

Problem

在某些文档中，Composable androidx.compose.material.NavigationRail具有可选的"居中"对齐方式.我无法用Jetpack Compose实现这一点.

"旧"XML属性是app:menuGravity="center" according to this tutorial.

Things I tried without success

我试图将NavigationRail(实际小部件的简单包装)放入一个带有对齐设置的框中:

Box(contentAlignment = Alignment.Center) {
    NavigationRail(
        selectedItem = selectedItem,
        onSelectItem = { selectedItem = it }
    )
}

并将其直接放入原始组合中:

NavigationRail(
    modifier = modifier.width(80.dp),
    backgroundColor = MaterialTheme.colors.surface
) {
   Box(contentAlignment = Alignment.Center) {
       for (item in NavigationItem.values()) {
      NavigationRailItem(
          selected = selectedItem == item,
          onClick = { onSelectItem.invoke(item) },
          icon = { Icon(item.icon, item.title) },
          alwaysShowLabel = true,
          selectedContentColor = MaterialTheme.colors.primaryVariant,
          unselectedContentColor = MaterialTheme.colors.primary,
          label = { Text(item.title, modifier = Modifier.padding(top = 8.dp)) }
      )
       }
   }
}

Screenhot