所以我在schedulefragment中有一段代码，我的目标是查看一个简单的日历查看器。但不幸的是，标题中提到了一个错误。即使我将“public class schedulefragment extends fragment”更改为“public class schedulefragment extends appcompatactivity”，它也会给@override带来一个错误。

@TargetApi(Build.VERSION_CODES.N)
public class ScheduleFragment extends Fragment {
CompactCalendarView compactCalendar;
private SimpleDateFormat dateFormatMonth = new SimpleDateFormat("MMM - yyyy", Locale.getDefault());
public ScheduleFragment() {
    // Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    return inflater.inflate(R.layout.fragment_schedule, container, false);
    final ActionBar actionBar =     getSupportActionBar();
    actionBar.setDisplayHomeAsUpEnabled(false);
    actionBar.setTitle(null);
    compactCalendar = (CompactCalendarView) findViewById(R.id.compactcalendar_view);
    compactCalendar.setUseThreeLetterAbbreviation(true);
    Event ev1 = new Event(Color.RED, 1477040400000L, "Teachers' Professional Day");
    compactCalendar.addEvent(ev1);
    compactCalendar.setListener(new CompactCalendarView.CompactCalendarViewListener() {
        @Override
        public void onDayClick(Date dateClicked) {
            Context context = getApplicationContext();
            if (dateClicked.toString().compareTo("Fri Oct 21 00:00:00 AST 2016") == 0) {
                Toast.makeText(context, "Teachers' Professional Day", Toast.LENGTH_SHORT).show();
            }else {
                Toast.makeText(context, "No Events Planned for that day", Toast.LENGTH_SHORT).show();
            }
        }
        @Override
        public void onMonthScroll(Date firstDayOfNewMonth) {
            actionBar.setTitle(dateFormatMonth.format(firstDayOfNewMonth));
        }
    });
}                  
}