#pragma mark - UISearchBarDelegate
//當搜尋文字被改變的時候呼叫

- (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText

{
　　//改變searchController中tableView的位置

    _searchController.searchResultsTableView.frame = CGRectMake(kZero, _tableViewY, kScreenW, kScreenH - _tableViewY);

    [[RealtimeSearchUtil currentUtil] realtimeSearchWithSource:self.dataSource searchText:(NSString *)searchText collationStringSelector:@selector(chatter) resultBlock:^(NSArray *results) {

        if (results) {

            dispatch_async(dispatch_get_main_queue(), ^{

                [self.searchController.resultsSource removeAllObjects];

                [self.searchController.resultsSource addObjectsFromArray:results];

                [self.searchController.searchResultsTableView reloadData];

            });

        }

    }];

}