如何在 Jetpack Compose 中设置“NavigationBar()”和“NavigationBarItem()”主题？

Question

我很难尝试更改选定/未选定图标和活动指示器的颜色。这些文档没有示例或正确的 Kdocs，而且我似乎无法在网上找到任何示例（请向我指出您知道的任何示例）。图标只是不改变颜色并保持黑色。

我的NavigationBar看起来像这样：

NavigationBar(
    containerColor = NavBarColor,
    contentColor = ContentColor, // <-- Can't tell what this is for.
    modifier = Modifier
        .align(Alignment.BottomCenter)
) {
    // ...
    destinations.forEachIndexed { index, item ->
        NavigationBarItem(
            selected = currentDestination?.hierarchy?.any { it.route == item.route } == true,

            onClick = {
                // ...
            },

            icon = {
                when (index) {
                    0 -> {
                        Icon(
                            imageVector = Icons.Rounded.Add,
                            contentDescription = stringResource(id = item.description)
                        )
                    }
                    1 -> {
                        Icon(
                            imageVector = Icons.Rounded.Home,
                            contentDescription = stringResource(id = item.description)
                        )
                    }
                    2 -> {
                        Icon(
                            imageVector = Icons.Rounded.Call,
                            contentDescription = stringResource(id = item.description)
                        )
                    }
                }
            },

            // Why on Earth does this not want to work:
            colors = NavigationBarItemDefaults.colors(
                selectedIconColor = NavBarColor, // <-- This doesn't work.
                unselectedIconColor = ContentColor, // <-- This doesn't work.
                indicatorColor = ContentColor // <-- This works.
            )
        )
    }
}

Answer 1

用于import androidx.compose.material3.Icon您的图标。

您在这里混合了材质和材质3代码：Icon从材质导入并使用材质LocalContentColor，另一方面NavigationBarItem是材质3视图并提供材质3 LocalContentColor。