Question

Scenario: User is viewing a screen with an image and some accompanying text in labels. User taps image and is brought to a screen that has the image only, and it needs to be zoomable. User taps that image and is brought back to the image/text screen.

Using storyboards I have implemented the first screen with

 @interface FirstImageViewController :  UIViewController <UIScrollViewDelegate>

That works. (btw though, I do not have zoom working on this screen)
I implemented the second screen with

 @interface SecondImageViewController : UIViewController  <UIScrollViewDelegate>

I tried to segue to the second screen with:

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {

[self performSegueWithIdentifier:@"SingleImage" sender:touch]; 
return YES;    

and

 - (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
 {
   self.secondImageViewController = segue.destinationViewController;
    [self.secondImageViewController setImageToDisplay:self.imageToDisplay];
 }

but get an error on the gestureRecognizer method:

* Terminating app due to uncaught exception ‘NSUnknownKeyException’, reason: ‘[ setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key imageDisplayer.’

I am not sure I am going about this the right way and could use help.

Rick

Answer 1

That error message is most often a symptom of a problem in your UI (whether xib or storyboard) where a view controller and its associated views are being loaded and there’s a reference to an outlet that doesn’t exist in code. Do you have a link in your storyboard to something called imageDisplayer?

(If you don’t see it, try right-clicking on your storyboard and choosing “Open As->Source Code” and doing a text search.)