iOS: Dictionary排序

NSArray *array = [[SCManager sharedManager].currentAlarmDic allValues];
    NSArray *arraySorted = [array sortedArrayUsingComparator:
                            ^NSComparisonResult(AlarmBean *obj1, AlarmBean *obj2) {
                                NSComparisonResult result = NSOrderedSame;
                                if (obj1.hour < obj2.hour) {
                                    result = NSOrderedAscending;
                                }else if (obj1.hour > obj2.hour) {
                                    result = NSOrderedDescending;
                                }
                                if (result == NSOrderedSame) {
                                    if (obj1.minute < obj2.minute) {
                                        result = NSOrderedAscending;
                                    }else if (obj1.minute > obj2.minute) {
                                        result = NSOrderedDescending;
                                    }
                                }
                                return result;  
                            }];
    AlarmBean *bean = (AlarmBean *)(arraySorted[indexPath.row]);