在实现 DatePickerDialog 的 DialogFragment 中添加中性按钮

Question

正如您在下面的代码中看到的那样，我尝试添加一个中性按钮来设置query_date 并关闭对话框。不幸的是，下面的这个不起作用：中性按钮根本不显示。

我想要一个名为“今天”的中间按钮并执行该操作。

public class DatePickerFragment extends DialogFragment implements DatePickerDialog.OnDateSetListener {

        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            // Use the current date as the default date in the picker
            AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
            builder.setNeutralButton("Today", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                    query_date = now_date;
                    dialog.dismiss();
                }
            });

            final Calendar c = Calendar.getInstance();
            int year = c.get(Calendar.YEAR);
            int month = c.get(Calendar.MONTH);
            int day = c.get(Calendar.DAY_OF_MONTH);

            DatePickerDialog dialog = new DatePickerDialog(getActivity(), this, year, month, day);
            dialog.getDatePicker().setMinDate(c.getTimeInMillis() );
            return dialog;
        }

        @SuppressLint("SimpleDateFormat")
        public void onDateSet(DatePicker view, int year, int month, int day) {
            // Do something with the date chosen by the user
            TimeZone tz = TimeZone.getDefault();
            SimpleDateFormat sdfSource = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZZZZZ");                
            sdfSource.setTimeZone(tz);
            Date date = new GregorianCalendar(year,month,day).getTime();
            SimpleDateFormat sdfDestination = new SimpleDateFormat("EEE', 'd LLL");

            query_date = sdfSource.format(date);
            change_date_button.setText(sdfDestination.format(date));

            load_more_bar.setVisibility(View.VISIBLE);
            new get_events().execute();
        }

    }

我从 onClick 按钮侦听器调用 DialogFragment 的方式如下：

DialogFragment newFragment = new DatePickerFragment();
newFragment.show(getActivity().getFragmentManager(), "datePicker"); 

DatePickerDialog 片段中是否可以有一个中性按钮？如果有怎么办？

Answer 1

您正在实例化两个对话框。一个 AlertDialog 和另一个 DatePickerDialog。你应该只使用一个：

@Override public Dialog onCreateDialog(Bundle savedInstanceState) {

 final Calendar c = Calendar.getInstance();
 int year = c.get(Calendar.YEAR);
 int month = c.get(Calendar.MONTH);
 int day = c.get(Calendar.DAY_OF_MONTH);

 DatePickerDialog dialog = new DatePickerDialog(getActivity(), this, year, month, day);
 dialog.getDatePicker().setMinDate(c.getTimeInMillis() );
 dialog.setButton(DialogInterface.BUTTON_NEUTRAL, "Today", new DialogInterface.OnClickListener() {
     public void onClick(DialogInterface dialog, int id) {
         query_date = now_date;
         dialog.dismiss();
     }
 });
 return dialog;

}