How to disable past dates in MaterialDatePicker?

问题

 //Material Date Picker
private val calendar = Calendar.getInstance()
private val constraintsBuilder = CalendarConstraints.Builder().setStart(calendar.timeInMillis)
private val builder = MaterialDatePicker.Builder.datePicker()
private val picker = builder
    .setSelection(calendar.timeInMillis)
    .setInputMode(MaterialDatePicker.INPUT_MODE_CALENDAR)
    .setCalendarConstraints(constraintsBuilder.build())
    .build()

I am using above code to open calendar setSelection method select current date and setStart only works for current month So i am unable to select previous month dates but i can still select past dates of current month.

If any can help me out. Please let me know. Thanks.

回答1:

You can build your own DateValidator or you can just use the DateValidatorPointForward provided by the library.

Something like:

//Returns a DateValidator which enables days from {@code point}, in 
//UTC milliseconds, forward
CalendarConstraints.DateValidator dateValidator = DateValidatorPointForward.from(yourDate);
constraintsBuilder.setValidator(dateValidator);

回答2:

You need to create your own DateValidator for this. A date being enabled/disabled depends on whether DateValidator.isValid() returns true or false

@Parcelize
class FutureDateValidator : CalendarConstraints.DateValidator {
    override fun isValid(date: Long): Boolean {
        return date > System.currentTimeMillis()
    }
}

And then use this validator as:

CalendarConstraints.Builder()
    .setValidator(FutureDateValidator())
    .build()

来源：https://stackoverflow.com/questions/61388666/how-to-disable-past-dates-in-materialdatepicker