Objective-c - Program crashes when UITableView is pulled down to refresh

Question

Post the code first

-(void)api:(NSString*)apiName successWithData:(id)responseData
{
    if ([apiName isEqualToString:kApi_image_list])  //比较apiName是否等于kApi_image_list (isEqualToString是字符串间的比较，==是指针间的比较)
    {
        [self.datas setArray:responseData];
    }
    [self.refreshControl endRefreshing];
    self.refreshControl.attributedTitle=[[NSAttributedString alloc]initWithString:@"下拉刷新"
                                                                       attributes:@{NSForegroundColorAttributeName:[UIColor whiteColor]}];
    [self.tableView reloadData];
    
}

Error code libc abi.dylib: terminating with uncaught exception of type NSException