Question

view1.h

#import “view2.h"

@interface ViewController : UIViewController 
{
int count;       
}
@property (nonatomic, assign) int count;

in view1.m

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{

if([segue.identifier isEqualToString:@"rating"])
{
    NSLog(@"identifier: help %@  \n",segue.identifier);

    view2 *vc = [segue destinationViewController];                                                 
    vc.imageNumber = &(count);

}
}

in view2.h

#import “view1.h"

@interface view2 : UIViewController


@property (nonatomic) int *imageNumber;

in view2.m

- (void)viewDidLoad
{
[super viewDidLoad];

NSLog(@"imagenumber %@\n",imageNumber);    

}

What is wrong here? Ideally I want to be able to send the info both ways… but I’m just trying to figure out what’s wrong with the one way transfer. Thanks.

Answer 1

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{

if([segue.identifier isEqualToString:@"rating"])
{
    NSLog(@"identifier: help %@  \n",segue.identifier);

    view2 *vc = [segue destinationViewController];  
    //viewDidLoad has already happened.                                               
    vc.imageNumber = &(count);

}
}

You check the int you set in viewDidLoad. viewDidLoad has already happened by the time you are in prepareForSegue. Try changing to use viewWillAppear or viewDidAppear and see what happens then. I think it should all work.

EDIT
Sorry i didn’t look at your NSLog closely enough. %@ in a format string, like what you use in NSLog is a stand in for an NSString, assumes the argument is an NSObject and tries to call [imageNumber description] which is obviously nonsensical in this case. In fact you need to use the standard integer marker in the format string and then dereference the pointer. The correct NSLog statement would look like this:

NSLog(@"imagenumber %d",*imageNumber);