Jetpack Compose切换按钮持续触发导致搜索栏UI故障

• 点击「Search Movies」后界面闪烁：isExpanded = !isExpanded被直接写在Composable的重组流程中，只要当前选中项为「Search Movies」，每次组件重组都会翻转isExpanded的值，进而触发新一轮重组，形成无限循环，最终表现为界面反复闪烁。
• 切换到「Popular Movies」后搜索框不隐藏：代码仅在选中「Search Movies」时修改isExpanded取值，切换到其他选项时未对isExpanded做重置，因此搜索框不会隐藏。

你需求的搜索框显隐逻辑完全可以通过selectedOption的取值直接判断，无需额外维护isExpanded状态变量，删掉冗余的状态即可解决两类异常。

@Composable
fun MaterialButtonToggleGroup() {
    val options = listOf(
        "Popular Movies",
        "Search Movies"
    )
    var selectedOption by remember {
        mutableStateOf("")
    }
    val onSelectionChange = { text: String ->
        selectedOption = text
    }
    Column() {
        Row(
            horizontalArrangement = Arrangement.SpaceEvenly,
            modifier = Modifier.fillMaxWidth(),
        ) {
            options.forEach { text ->
                Row(
                    modifier = Modifier
                        .padding(
                            vertical = 8.dp,
                        ),
                ) {
                    Text(
                        text = text,
                        style = typography.body1.merge(),
                        color = Color.White,
                        modifier = Modifier
                            .clip(
                                shape = RoundedCornerShape(
                                    size = 12.dp,
                                ),
                            )
                            .clickable {
                                onSelectionChange(text)
                            }
                            .background(
                                if (text == selectedOption) {
                                    Color.Magenta
                                } else {
                                    Color.Gray
                                }
                            )
                            .padding(
                                vertical = 12.dp,
                                horizontal = 16.dp,
                            ),
                    )
                }
            }
        }
        // 直接通过选中项判断搜索框是否展示
        if (selectedOption == "Search Movies") {
            var text by remember { mutableStateOf("") }
            OutlinedTextField(
                value = text,
                modifier = Modifier
                    .fillMaxWidth()
                    .padding(all = 3.dp),
                onValueChange = { text = it },
                label = { Text("Enter Movie Info") }
            )
        }
    }
    (activity as MainActivity?)?.viewSelection(selectedOption)
}

Surface {
    MaterialButtonToggleGroup()
}

内容的提问来源于stack exchange，提问作者petestmart