带有数字月份而不是命名的 Spinner DatePicker

问题描述

我有一个基本的 DatePicker，它是微调样式，没有任何布局。它看起来像这样：

class DatePickerFragment: DialogFragment(),DatePickerDialog.OnDateSetListener {

    private lateinit var date: Date

    interface Callbacks {
        fun onDateSelected(date: Date)
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        date = arguments?.getSerializable(ARG_DATE) as Date
    }

    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        val calendar = Calendar.getInstance().apply {
            time = date
        }

        val initialYear = calendar.get(Calendar.YEAR)
        val initialMonth = calendar.get(Calendar.MONTH)
        val initialDay = calendar.get(Calendar.DAY_OF_MONTH)

        return DatePickerDialog(
            requireContext(),this,initialYear,initialMonth,initialDay
        )
    }

    override fun onDateSet(view: DatePicker?,year: Int,month: Int,dayOfMonth: Int) {
        val selectedDate = GregorianCalendar(year,month,dayOfMonth).time
        targetFragment?.let { fragment ->
            (fragment as Callbacks).onDateSelected(selectedDate)
        }
    }

    companion object {
        fun getInstance(date: Date): DatePickerFragment {
            return DatePickerFragment().apply {
                arguments = Bundle().apply {
                    putSerializable(ARG_DATE,date)
                }
            }
        }
    }
}

private const val ARG_DATE = "date"

选择器正常工作。问题在于它显示月份名称（三字母格式），请参阅：

如何让 DatePicker 以数字方式显示月份（两位数格式）？ 换句话说，它会显示为 Mar 而不是 03。理想情况下，如果可能，我希望避免实现自定义微调器。

解决方法

您可以通过从 DatePicker 中找到月份 NumberPicker 并将显示的值设置为数字字符串来实现这一点。

进行以下更改：

1.在 onCreateDialog(savedInstanceState: Bundle?) 中使用自定义样式创建您的 DatePickerDialog，如下所示：

override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        val calendar = Calendar.getInstance().apply {
            time = date
        }

        val initialYear = calendar.get(Calendar.YEAR)
        val initialMonth = calendar.get(Calendar.MONTH)
        val initialDay = calendar.get(Calendar.DAY_OF_MONTH)

        val mPickerDialog: DatePickerDialog = object : DatePickerDialog(requireContext(),R.style.MyDatePickerDialogStyle,this,initialYear,initialMonth,initialDay) {
            override fun onDateChanged(view: DatePicker,year: Int,month: Int,dayOfMonth: Int) {
                super.onDateChanged(view,year,month,dayOfMonth)
                setNumericMonth(view)
            }
        }
        setNumericMonth(mPickerDialog.datePicker)
        return mPickerDialog
    }

其中 R.style.MyDatePickerDialogStyle 是用于设置 Spinner Style 的自定义样式，如下所示：

<style name="MyDatePickerDialogStyle" parent="android:Theme.Material.Dialog">
      <item name="android:datePickerStyle">@style/MyDatePickerStyle</item>
</style>
    
<style name="MyDatePickerStyle" parent="android:Widget.Material.DatePicker">
     <item name="android:datePickerMode">spinner</item>
 </style>

2.在 DatePickerFragment 中使用以下辅助函数将月份设置为数字，如下所示：

private fun setNumericMonth(datePicker: DatePicker) {
        val monthNumbers = arrayOf("01","02","03","04","05","06","07","08","09","10","11","12")
        val monthPicker = getMonthNumberPicker(datePicker)
        if (monthPicker != null) {
            monthPicker.displayedValues = monthNumbers
        }
    }

private fun getMonthNumberPicker(datePicker: DatePicker?): NumberPicker? {
        try {
            if (datePicker != null && datePicker.childCount > 0 && datePicker.getChildAt(0) is ViewGroup) {
                val vg = datePicker.getChildAt(0) as ViewGroup
                if (vg.childCount > 0 && vg.getChildAt(0) is ViewGroup) {
                    val vgPickers = vg.getChildAt(0) as ViewGroup
                    for (i in 0 until vgPickers.childCount) {
                        if (vgPickers.getChildAt(i) is NumberPicker && i == 1) {
                            return vgPickers.getChildAt(i) as NumberPicker
                        }
                    }
                }
            }
        } catch (e: Exception) {
        }
        return null
    }

结果：