Android, is there any way to disable writing inside a date picker using keyboard?

dp.setDescendantFocusability(DatePicker.FOCUS_BLOCK_DESCENDANTS);

is the best way to do so.

You can check this also

Focusable EditText inside ListView

myDatePicker.setDescendantFocusability(DatePicker.FOCUS_BLOCK_DESCENDANTS);

Calendar start = Calendar.getInstance();

            int Year = DatePicker.getYear();
            int Month = DatePicker.getMonth();
            int Day = DatePicker.getDayOfMonth();

            start.set(Year, Month, Day);
    //      DayDatePicker.setDescendantFocusability(DatePicker.FOCUS_BLOCK_DESCENDANTS);

            Date periodDate = start.getTime();
            int daysToAdd = 280;
            Calendar cal = Calendar.getInstance();

cal.add(Calendar.DAY_OF_MONTH,daysToAdd );
            System.err.println("-----" +cal.getTime());
            int AfterCalc = cal.getTime().getYear()+1900;
            System.err.println("-----" + AfterCalc);
            int AfterCalc2 = cal.getTime().getMonth();
            System.err.println("----" + AfterCalc2);