I need to make the minDate from 100 ago,because it is use for set the birthday . I had the code below,but it is from now to 100 years after .How to modify it ?

I have tried different ways ,such as add -100 years ,but not working .. And the most resolves I found are Java ..I will need with Kotlin

Thank you so much in advance !

class ThirdActivity : AppCompatActivity() {
    private var year = 0
    private var month = 0
    private var day = 0
    lateinit var edt :EditText
    private lateinit var calendar: Calendar
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_third)

        edt = findViewById(R.id.edt_birthday)
        edt.setOnClickListener {
            calendar = Calendar.getInstance()
            year = calendar.get(Calendar.YEAR)
            month = calendar.get(Calendar.MONTH)
            day = calendar.get(Calendar.DAY_OF_MONTH)

            val dialog = DatePickerDialog(this,AlertDialog.THEME_HOLO_LIGHT,{_,year,month,day_of_month->
                calendar[Calendar.YEAR] = year
                calendar[Calendar.MONTH] =month 1
                calendar[Calendar.DAY_OF_MONTH] = day_of_month
                val myFormat = "dd/MM/yyyy"
                val sdf = SimpleDateFormat(myFormat,Locale.getDefault())
                edt.setText(sdf.format(calendar.time))
            },calendar[Calendar.YEAR], calendar[Calendar.MONTH], calendar[Calendar.DAY_OF_MONTH])
            dialog.datePicker.minDate = calendar.timeInMillis
            dialog.datePicker.maxDate =calendar.timeInMillis
            calendar.add(Calendar.YEAR, 100)
            dialog.datePicker.maxDate = calendar.timeInMillis
            dialog.show()

        }

    }
}

activity_third.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ThirdActivity">

    <EditText
        android:id="@ id/edt_birthday"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="380dp"
        android:focusable="false"
        android:focusableInTouchMode="false"
        android:gravity="center"
        android:hint="Choose your birthday"
        android:inputType="text"
        android:textColor="@color/black"
        android:textSize="15sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="1.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

CodePudding user response：

edt.setOnClickListener {
                calendar = Calendar.getInstance()
                // create yearCal instance  and -100 years 
                val yearCal  = Calendar.getInstance()
                yearCal.add(Calendar.YEAR, -100)
                year = calendar.get(Calendar.YEAR)
                month = calendar.get(Calendar.MONTH)
                day = calendar.get(Calendar.DAY_OF_MONTH)
    
                val dialog = DatePickerDialog(this,
                    AlertDialog.THEME_HOLO_LIGHT,{ _, year, month, day_of_month->
                    calendar[Calendar.YEAR] = year
                    calendar[Calendar.MONTH] =month 1
                    calendar[Calendar.DAY_OF_MONTH] = day_of_month
                    val myFormat = "dd/MM/yyyy"
                    val sdf = SimpleDateFormat(myFormat,Locale.getDefault())
                    edt.setText(sdf.format(calendar.time))
                },calendar[Calendar.YEAR], calendar[Calendar.MONTH], calendar[Calendar.DAY_OF_MONTH])
                  //set minDate from yearCall
                dialog.datePicker.minDate = yearCal.timeInMillis
                dialog.datePicker.maxDate = calendar.timeInMillis
                dialog.show()
            }