ModalDrawer 需要协程上下文来更改状态隐藏和显示 jetpack compose

Question

我需要使用协程上下文来处理我的代码中的modalState.show() 或modalState.hide()

@ExperimentalMaterialApi
@Composable
fun ModalBottomSheetLayoutDemo() {
    val modalState = rememberModalBottomSheetState(ModalBottomSheetValue.Hidden)

    Button(modifier = Modifier.padding(16.dp), onClick = { modalState.show() }) {
        Text("Show Bottom Sheet")
    }

    ModalBottomSheetLayout(sheetState = modalState, sheetContent = {
        Text(
            modifier = Modifier.padding(start = 8.dp, top = 8.dp),
            text = "Title",
            fontWeight = FontWeight.Bold,
            style = typography.h5
        )
        Text(
            modifier = Modifier.padding(start = 8.dp, top = 8.dp),
            text = "Content example right here :)",
            style = typography.body1
        )
        Row(modifier = Modifier.align(Alignment.CenterHorizontally).padding(8.dp)) {
            Button(modifier = Modifier.padding(end = 8.dp), onClick = { modalState.hide() }) {
                Text("Cancel")
            }
            Button(onClick = { modalState.hide() }) {
                Text("Ok")
            }
        }
    }, sheetElevation = 8.dp) {}
}

在它工作之前，现在它需要一个协程上下文，如何在 jetpack compose 中执行上下文？

Answer 1

调用rememberCoroutineScope()，将其保存在一个变量中，然后将其用于launch() 你的show() 和hide() 调用：

@ExperimentalMaterialApi
@Composable
fun ModalBottomSheetLayoutDemo() {
    val modalState = rememberModalBottomSheetState(ModalBottomSheetValue.Hidden)
    val sillyScope = rememberCoroutineScope()

    Button(modifier = Modifier.padding(16.dp), onClick = { sillyScope.launch { modalState.show() } }) {
        Text("Show Bottom Sheet")
    }

    ModalBottomSheetLayout(sheetState = modalState, sheetContent = {
        Text(
            modifier = Modifier.padding(start = 8.dp, top = 8.dp),
            text = "Title",
            fontWeight = FontWeight.Bold,
            style = typography.h5
        )
        Text(
            modifier = Modifier.padding(start = 8.dp, top = 8.dp),
            text = "Content example right here :)",
            style = typography.body1
        )
        Row(modifier = Modifier.align(Alignment.CenterHorizontally).padding(8.dp)) {
            Button(modifier = Modifier.padding(end = 8.dp), onClick = { modalState.hide() }) {
                Text("Cancel")
            }
            Button(onClick = { sillyScope.launch { modalState.hide() } }) {
                Text("Ok")
            }
        }
    }, sheetElevation = 8.dp) {}
}

AFAICT，使用suspend调用是因为Compose UI中的动画API使用协程，所以我们需要应用一个合适的CoroutineScope。 rememberCoroutineScope() 将为您提供一个适用于您的作品的这个分支以某种形式存在的范围。