用底部navbar在屏幕之间保存状态-Jetpac组成

Question

如标题所建议的 - 我想保存屏幕元素的状态。也就是说，我想在屏幕A上切换一些东西，转到屏幕B，返回屏幕A，并在屏幕A中保存所有更改。我是Android开发的新手。据我了解，这种情况的解决方案之一是使用ViewModel。查看下面的代码。我试图用VM重写这件作品。

@Composable
fun DaysOfWeek(
    days: Int = 6,
    //viewModel: MyViewModel = MyViewModel()
){

    val states = remember{
        SnapshotStateList<Boolean>().also {
            for(day in 0..days){
                it.add(false)
            }
        }
    }
    
    val person = mutableListOf(0, 0, 0, 0, 0, 0, 0)
    val person1 = remember{ mutableStateOf(person) }
    /*val st = remember {
        viewModel.snap
    }*/

    Column() {
        Row(horizontalArrangement = Arrangement.SpaceEvenly){
            for(day in 0..days){
                DaysOfWeekContainer(
                    color = if (states[day]) Color.Green else Color.Transparent
                ){
                    DaysOfWeekButton(
                        onClick =
                        {
                            //viewModel.snapChanged(day)
                            states[day] = !states[day]
                            if(states[day]) person1.value.set(day, 1)
                            else person1.value.set(day, 0)
                        },
                        day = day
                    )
                }
            }
        }
        Spacer(modifier = Modifier.height(20.dp))
        Text("${person1.value}")
    }
}

VM：

class MyViewModel {
    //state
    var clicked by mutableStateOf(false)
    var color1 by mutableStateOf(Color.Transparent)
    var color2 by mutableStateOf(Color.Green)

    var rememem by mutableStateOf(
        SnapshotStateList<Boolean>().also {
            for(day in 0..6){
                it.add(false)
            }
        }
    )

    //events
    fun clickedChange(){clicked = !clicked}

    fun snapChanged(int: Int){
        rememem[int] = !rememem[int]
    }

}

我尝试了这一点，这就是工作！但是，当我在屏幕上的屏幕之间切换时，不会保存状态，

@Composable
fun DaysOfWeek(
    days: Int = 6,
    viewModel: MyViewModel = MyViewModel()
){
    
    val person = mutableListOf(0, 0, 0, 0, 0, 0, 0)
    val person1 = remember{ mutableStateOf(person) }

    Column() {
        Row(horizontalArrangement = Arrangement.SpaceEvenly){
            for(day in 0..days){
                DaysOfWeekContainer(
                    color = if(viewModel.rememem[day]) viewModel.color2 else viewModel.color1
                ){
                    DaysOfWeekButton(
                        onClick =
                        {
                            viewModel.snapChanged(day)
                            if(viewModel.rememem[day]) person1.value.set(day, 1)
                            else person1.value.set(day, 0)
                        },
                        day = day
                    )
                }
            }
        }
        Spacer(modifier = Modifier.height(20.dp))
        Text("${person1.value}")
    }
}

我有7个按钮，每次我单击其中一个按钮时，它们会更改颜色。 我该如何解决问题使用VM。屏幕上的状态更改，但切换屏幕时没有保存。

谢谢你！