storyboard传值

#pragma mark - Navigation// In a storyboard-based application, you will often want to do a little preparation before navigation- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {    // Get the new view controller using [segue destinationViewController].    // Pass the selected object to the new view controller.            //得到点击的cell，sender是指触发跳转的那个控件，这里指的是点击的cell    UITableViewCell *cell = (UITableViewCell *)sender;        //通过当前被点击的cell得到点击位置    NSIndexPath *selectedIndexPath = [self.tableView indexPathForCell:cell];        Roster *roster = self.rosterArray[selectedIndexPath.row];        //得到要跳转的viewcontroller    ChatTableViewController *chatTableViewController = (ChatTableViewController *)[segue destinationViewController];        chatTableViewController.chatToRoster = roster;    }