Restrict Range in Android DatePicker Custom Dialog

问题

I have a custom linear layout which has DatePicker and TimePicker widgets in it. This is used as DateTime picker. I want to restrict the DatePicker by way of setMaxDate() and setMinDate(). I have done:

dp.setMaxDate(new DateTime().minusDays(1).getMillis());
dp.setMinDate(new DateTime().minusDays(30).getMillis());

The dates beyond this range are actually grayed out when the dialog appears. But I can still select a grayed date. I have stumbled upon this. But, what is the work around for a custom layout with datepicker in it?

回答1:

For future readers!

Actually with new android material design components what you want achieve could be achieved using MaterialDatePicker. And dates outside the allowed range is not selectable.

---

Steps

1. Add material dependency to your module's gradle file

implementation 'com.google.android.material:material:1.1.0-beta01'

2. Change app theme to inherit from a version of material theme.

ex:

<style name="AppTheme" parent="Theme.MaterialComponents.Light.NoActionBar">

3. Use following code to initiate the dialog.

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)
        }
    }

}

回答2:

The Material Components Library provides the MaterialDatePicker.
You can use a DateValidator to restrict the selections.
In particular you can use the built-in validators:

• DateValidatorPointForward that enables dates from a given point forward
• DateValidatorPointBackward that enables only dates before a given point.

Something like:

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());

来源：https://stackoverflow.com/questions/36004398/restrict-range-in-android-datepicker-custom-dialog