Question

I’m new to xCode and objective-c, and trying to use different classes to familiarize myself with the language.

I was trying to use an NSMutableArray to show several pictures and a corresponding textsnippet to tell about the picture. I have a segmentedControl to switch between several choices. Using an UIImageView to show a picture, and a UITextView the corresponding text.

But for some reason they will not load properly? The picture and the text isn’t shown. What am I doing wrong?

@interface TestingViewController : UIViewController{
    UIImageView *pic;
    UITextView *description;
    UISegmentedControl *choice;
    NSMutableArray *infoDescription;
}

@property (nonatomic, retain) IBOutlet UIImageView *pic;
@property (nonatomic, retain) IBOutlet UITextView *description;
@property (nonatomic, retain) NSMutableArray *infoDescription;
@property (nonatomic, retain) IBOutlet UISegmentedControl *choice;

- (IBAction) segmentedControllIndexChanged;

@end

- (void)viewDidLoad
{
   [super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
      infoDescription = [[NSMutableArray alloc] init];

}

UIImage *miko = [UIImage imageNamed:@"miko.jpg"];
NSString *mikoString = @"Info about Miko";
UIImage *alex = [UIImage imageNamed:@"alex.jpg"];
NSString *alexString = @"Info about Alex";

[infoDescription addObject:miko];
[infoDescription addObject:mikoString];
[infoDescription addObject:alex];
[infoDescription addObject:alexString];

- (IBAction)segmentedControllIndexChanged{

switch (choice.selectedSegmentIndex) {
    case 0:
       [pic setImage: miko];
        [pic setImage: [infoDescription objectAtIndex:0]];
       [description setText: [[infoDescription objectAtIndex:1] stringValue]];    
        break;
    case 1:
      [pic setImage: [infoDescription objectAtIndex:2]];
      [description setText: [[infoDescription objectAtIndex:3] stringValue]];
        break;
    default:
        break;
}   

}

Thanks for any help out there.

Answer 1

NSMutableArray should not be an IBOutlet ..

Change this

@property (nonatomic, retain) IBOutlet NSMutableArray *infoDescription;

to

@property (nonatomic, retain) NSMutableArray *infoDescription;

and make sure you synthesize it..
and also the program isn’t working since your array is not initialized and is not adding objects to it.

put this in ViewDidLoad

infoDescription = [[NSMutableArray alloc] init];