我有一个自定义的线性布局，其中包含DatePicker小TimePicker部件。这用作DateTime选择器。我想通过setMaxDate()and来限制 DatePicker setMinDate()。我已经做好了：
dp.setMaxDate(new DateTime().minusDays(1).getMillis());
dp.setMinDate(new DateTime().minusDays(30).getMillis());
当对话框出现时，超出此范围的日期实际上是灰色的。但我仍然可以选择一个灰色的日期。我偶然发现了这一点。但是，其中包含 datepicker 的自定义布局的解决方法是什么？
给未来的读者！
实际上，使用新的android 材料设计组件可以使用MaterialDatePicker. 超出允许范围的日期是不可选择的。
脚步
1. 将材料依赖添加到模块的 gradle 文件中
implementation 'com.google.android.material:material:1.1.0-beta01'
2.更改应用主题以继承材料主题的版本。
前任：
<style name="AppTheme" parent="Theme.MaterialComponents.Light.NoActionBar">
3. 使用以下代码启动对话框。
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
setupRangePickerDialog()
}
private fun setupRangePickerDialog() {
val builderRange = MaterialDatePicker.Builder.dateRangePicker()
builderRange.setCalendarConstraints(limitRange().build())
val pickerRange = builderRange.build()
pickerRange.show(supportFragmentManager, pickerRange.toString())
}
/*
Limit selectable range to Oct 17 - Nov 20 2019
*/
private fun limitRange(): CalendarConstraints.Builder {
val constraintsBuilderRange = CalendarConstraints.Builder()
val calendarStart: Calendar = GregorianCalendar.getInstance()
val calendarEnd: Calendar = GregorianCalendar.getInstance()
val year = 2019
calendarStart.set(year, 10, 17)
calendarEnd.set(year, 11, 20)
val minDate = calendarStart.timeInMillis
val maxDate = calendarEnd.timeInMillis
constraintsBuilderRange.setStart(minDate)
constraintsBuilderRange.setEnd(maxDate)
constraintsBuilderRange.setValidator(RangeValidator(minDate, maxDate))
return constraintsBuilderRange
}
}
class RangeValidator(private val minDate:Long, private val maxDate:Long) : CalendarConstraints.DateValidator{
constructor(parcel: Parcel) : this(
parcel.readLong(),
parcel.readLong()
)
override fun writeToParcel(dest: Parcel?, flags: Int) {
TODO("not implemented")
}
override fun describeContents(): Int {
TODO("not implemented")
}
override fun isValid(date: Long): Boolean {
return !(minDate > date || maxDate < date)
}
companion object CREATOR : Parcelable.Creator<RangeValidator> {
override fun createFromParcel(parcel: Parcel): RangeValidator {
return RangeValidator(parcel)
}
override fun newArray(size: Int): Array<RangeValidator?> {
return arrayOfNulls(size)
}
}
}
材料组件库提供MaterialDatePicker.
您可以使用 aDateValidator来限制选择。
特别是您可以使用内置的验证器：
DateValidatorPointForward 启用从给定点向前的日期DateValidatorPointBackward仅启用给定点之前的日期。就像是：
MaterialDatePicker.Builder<Pair<Long, Long>> builderRange = MaterialDatePicker.Builder.dateRangePicker();
CalendarConstraints.Builder constraintsBuilderRange = new CalendarConstraints.Builder();
//....define min and max for example with LocalDateTime and ZonedDateTime or Calendar
CalendarConstraints.DateValidator dateValidatorMin = DateValidatorPointForward.from(min.getTimeInMillis());
CalendarConstraints.DateValidator dateValidatorMax = DateValidatorPointBackward.before(max.getTimeInMillis());
ArrayList<CalendarConstraints.DateValidator> listValidators =
new ArrayList<CalendarConstraints.DateValidator>();
listValidators.add(dateValidatorMin);
listValidators.add(dateValidatorMax);
CalendarConstraints.DateValidator validators = CompositeDateValidator.allOf(listValidators);
constraintsBuilderRange.setValidator(validators);
builderRange.setCalendarConstraints(constraintsBuilderRange.build());
MaterialDatePicker<Pair<Long, Long>> pickerRange = builderRange.build();
pickerRange.show(getSupportFragmentManager(), pickerRange.toString());
如果有人想要 RangeValidator（上面发布）但代码更少：（添加了@Parcelize 注释）
@Parcelize
internal class RangeValidator(
private var minDate: Long = 0,
private var maxDate: Long = 0) : DateValidator {
override fun isValid(date: Long): Boolean {
return !(minDate > date || maxDate < date)
}
}