LocalDateTime plusDays（）在月底时不起作用

Question

我今天（5 月 30 日）使用自定义小时和分钟测试我的应用程序：

var today=LocalDateTime.now().withHour(hour).withMinute(minute).withSecond(0).withNano(0)

但是，当我这样做时：

 today=today.plusDays(1) //today is: 2022-03-30T10:04

在日志中是return：

2022-03-30T10:04

UPDATE：这是完整的代码。我正在 Android 8.1.0

上进行测试

fun calcEndTime(hour: Int, minute: Int, initinmilliseconds:Long):Long {

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        var endtime =LocalDateTime.now().withHour(hour).withMinute(minute).withSecond(0).withNano(0)
        val now = LocalDateTime.now().withSecond(0).withNano(0)
        val inittime = Instant.ofEpochMilli(initinmilliseconds).atZone(ZoneOffset.UTC).toLocalDateTime()
        val days=inittime.dayOfMonth-now.dayOfMonth

        if(days==1||days<0){
            endtime=endtime.plusDays(1)
            Log.d("ZXCV","if ${endtime}")
        }

        if (endtime.isBefore(now)) {
            endtime = endtime.plusDays(1)
        }
        return endtime.toInstant(ZoneOffset.UTC).toEpochMilli()
        }
    }

Answer 1

这样试过，好像还不错

fun calcEndTime(hour: Int, minute: Int, initinmilliseconds: Long): LocalDateTime {
    var endtime = LocalDateTime.now().withHour(hour).withMinute(minute).withSecond(0).withNano(0)
    val now = LocalDateTime.now().withSecond(0).withNano(0)
    val inittime = Instant.ofEpochMilli(initinmilliseconds).atZone(ZoneOffset.UTC).toLocalDateTime()
    val days = inittime.dayOfMonth - now.dayOfMonth

    if (days == 1 || days < 0) {
        endtime = endtime.plusDays(1)
        Log.d("ZXCV", "if ${endtime}")
    }

    if (endtime.isBefore(now)) {
        endtime = endtime.plusDays(1)
        Log.d("ZXCV2", "if ${endtime}")
    }
    return endtime//.toInstant(ZoneOffset.UTC).toEpochMilli() // try commenting this out to return LocalDateTime instead
}

示例用法：

binding.buttonFirst.setOnClickListener {
        val hour = 10
        val minute = 4
        var today = calcEndTime(hour, minute, 1648706400000)

        var test = "TESTING today" + "\n"
        test += today.toString() + "\n"


        today = today.plusDays(1)
        test += today.toString() + "\n"
        binding.textviewFirst.text = test
    }

截图

LocalDateTime plusDays（）在月底时不起作用

LocalDateTime plusDays() dont work when is the end of the month

android

date

kotlin

localdatetime