Special Muesli's questions

文档

// MyActivity.kt file

class MyActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setContent {
            // Calculate elevations based on the system theme
            val elevations = if (isSystemInDarkTheme()) {
                Elevations(card = 1.dp, default = 1.dp)
            } else {
                Elevations(card = 0.dp, default = 0.dp)
            }

            // Bind elevation as the value for LocalElevations
            CompositionLocalProvider(LocalElevations provides elevations) {
                // ... Content goes here ...
                // This part of Composition will see the `elevations` instance
                // when accessing LocalElevations.current
            }
        }
    }
}

当CompositionLocalProvider他们说“Content goes here它应该/可以是什么样的内容？”

我只是在寻找全局变量，而这一切都与有关Compose。

有这个简单的例子：

@Composable
fun SimpleFilledTextFieldSample() {
    var text by remember { mutableStateOf("Hello") }

    TextField(
        value = text,
        onValueChange = { text = it },
        label = { Text("Label") }
    )
}

我想了解每次用户按下某个键时“onValueChange”是否都会更新（即调用）？
我在 android jetpack compose 文档中找不到答案。