java - 如何在材料组件的 dateRangePicker 上使用 setSelection？

Question

我想在打开 dateRangePicker 时显示选定的日期范围，我知道 setSelected 方法适用于此，我试过它不起作用，或者可能做错了什么，请帮助

这是我已经尝试过的

public void openDateRangePicker(View view) {
 MaterialDatePicker.Builder builder =
                MaterialDatePicker.Builder.dateRangePicker();

        CalendarConstraints.Builder constraintsBuilder = new CalendarConstraints.Builder();

        MaterialDatePicker<Pair<Long,Long>> picker = builder.build();
        builder.setCalendarConstraints(constraintsBuilder.build());

        picker.setStyle(DialogFragment.STYLE_NORMAL, R.style.Custom_MaterialCalendar_Fullscreen);
        if(!firstDateStr.isEmpty() || !endDateStr.isEmpty()){
            builder.setSelection(selectionDates);

        }
        picker.show(getSupportFragmentManager(), picker.toString());



    picker.addOnPositiveButtonClickListener(new MaterialPickerOnPositiveButtonClickListener<Pair<Long, Long>>() {
        @Override
        public void onPositiveButtonClick(Pair<Long, Long> selection) {

            long firstDateLong = selection.first;
            Date firstDate=new Date(firstDateLong);
            long endDateLong = selection.second;
            Date endDate=new Date(endDateLong);

            SimpleDateFormat sdf2 = new SimpleDateFormat("yyyy-MM-dd", Locale.getDefault());

            //format yyyy-MM-dd
            firstDateStr = sdf2.format(firstDate);
            endDateStr = sdf2.format(endDate);
            selectionDates = selection;


            selectedDatesStr = firstDateStr + " to " + endDateStr ;//+ " (" + (daysBetween + 1) + " days)";
            tvDates.setText(selectedDatesStr);
            tvDates.setTypeface(Typeface.DEFAULT_BOLD);
            picker.dismiss();

        }
    }); 

}

我在这里所做的是保存选择对象并在下次打开选择器时使用它来显示范围，但它打开时没有任何选择，就像它第一次打开一样！

标签： javaandroidmaterial-components-androiddaterangepicker

Answer 1

您的线路顺序很重要，您需要builder.build();在完成构建器设置后调用。

  String firstDateStr="";
  String endDateStr="";

Pair<Long, Long> selectionDates=null;
public void openDateRangePicker() {

   MaterialDatePicker.Builder builder =
            MaterialDatePicker.Builder.dateRangePicker();

    CalendarConstraints.Builder constraintsBuilder = new CalendarConstraints.Builder();

    builder.setCalendarConstraints(constraintsBuilder.build());

   // picker.setStyle(DialogFragment.STYLE_NORMAL);
    if(selectionDates!=null){
        builder.setSelection(selectionDates);

    }
    MaterialDatePicker<Pair<Long,Long>> picker = builder.build();
    picker.show(getSupportFragmentManager(), picker.toString());



    picker.addOnPositiveButtonClickListener(new MaterialPickerOnPositiveButtonClickListener<Pair<Long, Long>>() {
        @Override
        public void onPositiveButtonClick(Pair<Long, Long> selection) {

            long firstDateLong = selection.first;
            Date firstDate=new Date(firstDateLong);
            long endDateLong = selection.second;
            Date endDate=new Date(endDateLong);

            SimpleDateFormat sdf2 = new SimpleDateFormat("yyyy-MM-dd", Locale.getDefault());

            //format yyyy-MM-dd
            firstDateStr = sdf2.format(firstDate);
            endDateStr = sdf2.format(endDate);
            selectionDates = selection;


            selectedDatesStr = firstDateStr + " to " + endDateStr ;//+ " (" + (daysBetween + 1) + " days)";
           tvDates.setText(selectedDatesStr);
          tvDates.setTypeface(Typeface.DEFAULT_BOLD);
            picker.dismiss();

        }
    });

}