Android Compose：強制折疊所有展開的卡片，當前選中的卡片除外

Question

我目前正在研究可擴展卡的列表。 我想關閉除當前選定的以外的所有其他打開的可擴展卡片。

我正在使用的數據是一個 Map<String, String>，但是我不知道如何獲取對列表中項目列表的引用以循環遍歷它並關閉所有其他期望當前的項目。 任何建議都會非常有幫助！

val size = viewModel.getQuestionsAndAnswers(groupName).size
            Column {
                var i = 0
                for(question in viewModel.getQuestionsAndAnswers(groupName)) {
                    ExpandableCard(
                        title =  question.key,
                        description = question.value,
                        position = i++,
                        onExpandableCardClicked = {
                            // question: how do I loop over all the items in expandable cards and close them.
                        }
                    )
                }
            }

Answer 1

你可以有一個 state 通知當前打開的卡的索引：

val selectedIndexState = rememberSaveable {
        mutableStateOf(-1)
    }

然后向ExpandableCard添加一個isExpanded參數：

ExpandableCard(
    title = question.key,
    description = question.value,
    position = i++,
    isExpanded = selectedIndexState.value == i,
    onExpandableCardClicked = {
        selectedIndexState.value = i
    }
)

在處理這樣的列表時，您也可以考慮使用LazyColumn ：

val selectedIndexState = rememberSaveable {
    mutableStateOf(-1)
}
LazyColumn {
    itemsIndexed(
        items = viewModel.getQuestionsAndAnswers(groupName).toList()
    ) { index, question ->
        ExpandableCard(
            title = question.first,
            description = question.second,
            position = index,
            isSelected = selectedIndexState.value == index,
            onExpandableCardClicked = {
                selectedIndexState.value = index
            }
        )
    }
}