在视图中输入星期几的简单方法是什么？答案

【问题标题】：whats a simple way of inputting days of the week in a view?在视图中输入星期几的简单方法是什么？
【发布时间】：2021-07-07 12:42:16
【问题描述】：

所以我有 3 个文本视图来显示未来 3 天的预测。我使用视图绑定来绑定视图，但我觉得有一种更简单的方法来编写它，但我想不出解决方案。如何遍历一周中的几天并相应地设置文本视图？

'''
// getting day of the week
private val dayOfWeek: DayOfWeek = LocalDate.now().dayOfWeek
// getting day of week as int value
private val dayNum: Int = dayOfWeek.value

'''

     ''' // 1 = monday etc

      private fun forecastDays() {


        when (dayNum){
            // forecast of next three days
            1 -> {
                binding.tvDay1.text = "Tuesday"
                binding.tvDay2.text = "Wednesday"
                binding.tvDay3.text = "Thursday"
            }
            2 -> {
                binding.tvDay1.text = "Wednesday"
                binding.tvDay2.text = "Thursday"
                binding.tvDay3.text = "Friday"
            }
            3 -> {
                binding.tvDay1.text = "Thursday"
                binding.tvDay2.text = "Friday"
                binding.tvDay3.text = "Saturday"
            }
            4 -> {
                binding.tvDay1.text = "Friday"
                binding.tvDay2.text = "Saturday"
                binding.tvDay3.text = "Sunday"
            }
          .. etc

'''

【问题讨论】：

标签： java android kotlin android-viewbinding

【解决方案1】：

我猜你可以用DateFormatter 来做。这是使用地图的另一种方法。您可以将daysMap 设为常量。

val daysMap = mapOf(
    1 to "Sunday", 2 to "Monday", 3 to "Tuesday", 4 to "Wednesday", 5 to "Thursday", 6 to "Friday", 7 to "Saturday"
)
val dayOfWeek: DayOfWeek = LocalDate.now().dayOfWeek
val dayNum: Int = dayOfWeek.value
binding.tvDay1.text = daysMap[(dayNum + 1) % 7]
binding.tvDay2.text = daysMap[(dayNum + 2) % 7]
binding.tvDay3.text = daysMap[(dayNum + 3) % 7]

【讨论】：

非常感谢！现在一切都解决了:)。我知道这是非常简单的事情，我会更多地复习 kotlin/java 知识:)

【解决方案2】：

DayOfWeek 是一个Enum，这意味着您可以使用序号作为索引以数字方式获取 DayOfWeek。

// getting day of the week
private val dayOfWeek: DayOfWeek = LocalDate.now().dayOfWeek
// ordinal
private val dayNum: Int = dayOfWeek.ordinal()
...
private fun forecastDays() {

    binding.tvDay1.text = DayOfWeek.values()[(dayNum + 1) % 7].name()
    binding.tvDay2.text = DayOfWeek.values()[(dayNum + 2) % 7].name()
    binding.tvDay3.text = DayOfWeek.values()[(dayNum + 3) % 7].name()
...

【讨论】：