moving indexPath.row to a label using addTarget: action: forControlEvents: - ios

Question

I am trying to move my indexPath.row to a different viewcontroller - pageView label. This is what I have tried:
[cell.nav addTarget:self action:#selector(naviguate:) forControlEvents:UIControlEventTouchUpInside];
cell.nav.tag=indexPath.row;
-(void)naviguate:(id)sender {
UIButton *theButton=(UIButton *)sender;
NSLog(names[theButton.tag]);
pageView *secondViewController = [[pageView alloc] initWithNibName:#"secondViewController" bundle:nil];
secondViewController.name.text = names[theButton.tag];
}
Why is this not changing the label text on pageView. How should I do it?
Where the Logs string works fine.
Edit for #danh
I have tried this:
-(void)naviguate:(id)sender {
[UIView animateWithDuration:0.5
delay:0
options: UIViewAnimationOptionCurveEaseOut
animations:^{
[_tableView setFrame:CGRectMake(0, 569, _tableView.frame.size.width, _tableView.frame.size.height)];
}
completion:^(BOOL finished){
[self performSegueWithIdentifier:#"link" sender:self];
}];
}
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
UIButton *theButton=(UIButton *)sender;
if([segue.identifier isEqualToString:#"link"])
{
UINavigationController *navController = (UINavigationController *)segue.destinationViewController;
pageView *controller = (pageView *)navController.topViewController;
controller.name.text= names[theButton.tag];
}
}
where it is being called by
[cell.nav addTarget:self action:#selector(naviguate:) forControlEvents:UIControlEventTouchUpInside];
cell.nav.tag=indexPath.row;
But I am getting the error [pageView topViewController]: unrecognized selector sent to instance ... Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[pageView topViewController]: unrecognized selector sent to instance
Do you know why?
2nd attempt
with:
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
UIButton *theButton=(UIButton *)sender;
if([segue.identifier isEqualToString:#"link"])
{
pageView *controller = (pageView *)segue.destinationViewController;
controller.name.text= names[theButton.tag];
}
}
I get the error '-[ImagesTableViewController tag]: unrecognized selector sent to instance
WHich is crashing because of names[theButton.tag] How come?

Answer 1

This line:
pageView *secondViewController = [[pageView alloc] initWithNibName:#"secondViewController" bundle:nil];
creates a new view controller, then this line:
secondViewController.name.text = names[theButton.tag];
sets one of it's view's properties (which is wrong, because the view isn't loaded yet, and because it's ill-advised to mess around with another vc's views). But that doesn't really matter, because this line:
}
destroys the newly allocated vc, which will never be heard from again.
The way to fix is either to use a segue from the starting view controller, and set properties of the destination in prepareForSegue:, or to push or present the secondViewController. Either:
// if we're in a navigation controller
[self.navigationController pushViewController:secondViewController animated:true];
// or, if there's no container
[self presentViewController:secondViewController animated:true completion:nil];
Remember, no matter how you decide to present secondViewController, don't try to set the state of one of it's subviews directly. Instead, give it a property like NSString *theStringMyLabelShouldShow, and set that from the presenting vc. The second VC can mess with it's own views in viewWillAppear:
self.name.text = self.theStringMyLabelShouldShow;