Android Composable如何更新其他Composable function更好的方法？

Question

Screenshot

I just wanna click button can log ComposeableB().or liek this, For example, if you click ComposableA, ComposableB will start an animation instead of updating the data.

Answer 1

Although with Compose it is generally recommended to pass events to the app logic (like the ViewModel) instead of to the app UI ( Thinking in Compose ), here's how your code could look like if you really need to do that:

@Composable
fun ComposableA() {
    val addLogEntry = remember { mutableStateOf(false) }

    Column {
        Button(onClick = {
            addLogEntry.value = true
        }) {
            Text(text = "Log")
        }
        ComposableB(addLogEntry = addLogEntry.value) {
            addLogEntry.value = false
        }
    }
}

@Composable
fun ComposableB(
    addLogEntry: Boolean,
    onLogEntryAdded: () -> Unit
) {
    if (addLogEntry) {
        Log.d("Shadowmeld", "onAddLogEntry")
        onLogEntryAdded()
    }
}

Here you are passing a function as a second parameter (onLogEntryAdded, in lambda expression format) to ComposableB. This passed lambda expression will be called from ComposableB to modify state in ComposableA.

I believe there are better ways of doing this, like ComposableB being declared inside ComposableA (hoisting state to ComposableA) or, if that is not an option, passing the Button onClick event to a ViewModel that both ComposableA and ComposableB can observe.