5.15

在网上找了一个jetpack compose 的 日期时间选择器

但是还不知到 怎么将里面的时间提取出来

```

@Preview
@Composable
fun DataTimePicker(
    viewModel: TimeViewModel = viewModel(factory = TimeViewModelProvider.Factory),
    date: Date = Date()
) {

    val itemHeight = 50.dp

    Box(
        modifier = Modifier
            .wrapContentHeight()
            .fillMaxWidth(),
        Alignment.Center
    ) {
        Row(
            Modifier
                .wrapContentHeight()
//                .fillMaxWidth()
                .background(MaterialTheme.colorScheme.surface),
            Arrangement.SpaceEvenly,
            Alignment.CenterVertically
        ) {
            val year = date.getYearr()
            val selectYear = rememberSaveable { mutableStateOf(year) }
            val years = LinkedList<Pair<Int, String>>().apply {
                for (i in year downTo 1980) {
                    add(Pair(i, "${i}年"))
                }
            }
            DatePickerColumn(years, itemHeight, 55.dp, selectYear)

            //  月份
            val month = date.getMonthh()
            val selectMonth = rememberSaveable { mutableStateOf(month) }
            val months = ArrayList<Pair<Int, String>>(12).apply {
                for (i in 1..12) {
                    add(Pair(i, "${i}月"))
                }
            }
            DatePickerColumn(months, itemHeight, 40.dp, selectMonth)

            //  月份的天数
            val dayOfMon = date.getDayOfMonth()
            val selectDay = rememberSaveable { mutableStateOf(dayOfMon) }
            val dayCountOfMonth =
                DateUtil.getDayCountOfMonth(selectYear.value, selectMonth.value)

            //  提前定义好
            val day31 = ArrayList<Pair<Int, String>>().apply {
                for (i in 1..31)
                    add(Pair(i, "${i}日"))
            }
            val day30 = ArrayList<Pair<Int, String>>().apply {
                for (i in 1..30)
                    add(Pair(i, "${i}日"))
            }
            val day29 = ArrayList<Pair<Int, String>>().apply {
                for (i in 1..29)
                    add(Pair(i, "${i}日"))
            }
            val day28 = ArrayList<Pair<Int, String>>().apply {
                for (i in 1..28)
                    add(Pair(i, "${i}日"))
            }

            //  快速切换
            val dayOfMonList = when (dayCountOfMonth) {
                28 -> day28
                29 -> day29
                30 -> day30
                else -> day31
            }

            DatePickerColumn(
                pairList = dayOfMonList,
                itemHeight = itemHeight,
                valueState = selectDay
            )

            //  小时
            val hour = date.getHour()
            val selectHour = rememberSaveable { mutableStateOf(hour) }
            val hours = ArrayList<Pair<Int, String>>(24).apply {
                for (i in 0..23) {
                    add(Pair(i, "${i}时"))
                }
            }
            DatePickerColumn(hours, itemHeight, 40.dp, selectHour)

            //  分
            val minute = date.getMinute()
            val selectMinute = rememberSaveable { mutableStateOf(minute) }
            val minutes = ArrayList<Pair<Int, String>>(60).apply {
                for (i in 0..59) {
                    add(Pair(i, "${i}分"))
                }
            }
            DatePickerColumn(minutes, itemHeight, 40.dp, selectMinute)

            //  秒
            val second = date.getSecond()
            val selectSecond = rememberSaveable { mutableStateOf(second) }
            val seconds = ArrayList<Pair<Int, String>>(60).apply {
                for (i in 0..59) {
                    add(Pair(i, "${i}秒"))
                }
            }
            DatePickerColumn(seconds, itemHeight, 40.dp, selectSecond)
        }
    }

```