Jetpack Compose：如何禁用浮动操作按钮？

根据docs https://developer.android.com/reference/kotlin/androidx/compose/material/package-summary#FloatingActionButton(kotlin.Function0,androidx.compose.ui.Modifier,androidx.compose.foundation.interaction.MutableInteractionSource,androidx.compose.ui.graphics.Shape,androidx.compose.ui.graphics.Color,androidx.compose.ui.graphics.Color,androidx.compose.material.FloatingActionButtonElevation,kotlin.Function0)，我们可以通过设置禁用FABnull to its onClick:

onClick - 当用户单击此 FAB 时将被调用。 FAB 将 当它为空时被禁用。

当我尝试时我偶然发现onClick参数不可为空，

那么，如何禁用FAB呢？

现在 （1.x.y) the FloatingActionButton不支持enabled财产。

作为解决方法，您可以使用Button with a CircleShape.

var enabled by remember { mutableStateOf(false) }
Button(
    onClick = { /* do something */},
    modifier = Modifier.defaultMinSize(minWidth = 56.dp, minHeight = 56.dp),
    enabled = enabled,
    shape = CircleShape

){
    Icon(Icons.Filled.Favorite, contentDescription = "Localized description")
}

如果你想使用FloatingActionButton你可以这样做：

var enabled by remember { mutableStateOf(false) }


CompositionLocalProvider(LocalRippleTheme provides
        if (enabled)  LocalRippleTheme.current else NoRippleTheme) {
    FloatingActionButton(
        backgroundColor = if (enabled) MaterialTheme.colors.secondary else Gray,
        onClick = { if (enabled) { /* do something */ } else {} },
    ) {
        Icon(Icons.Filled.Favorite,
            contentDescription = "Localized description",
        tint = if (enabled)
            LocalContentColor.current.copy(alpha = LocalContentAlpha.current)
        else DarkGray)
    }
}

with:

private object NoRippleTheme : RippleTheme {
    @Composable
    override fun defaultColor() = Color.Unspecified

    @Composable
    override fun rippleAlpha(): RippleAlpha = RippleAlpha(0.0f, 0.0f, 0.0f, 0.0f)
}