Question

in my application i’m trying to send an int value from one view to another view. To do this i’m setting up a navbar button programmatically and passing it an action from the same class that’s creating the button. In the next view that will load i have a property that i’ll set when the user clicks the navbar button. The problem is that the application crashes when i set this value. I have the int value in a @property in the view’s h class and then i have the @synthesize below the @implementation line.

Here is the code for the navbar button, this is done in the initWithNibName method:

UIBarButtonItem *contentsButton = [[UIBarButtonItem alloc] initWithTitle:@"Contents"                                            style:UIBarButtonItemStyleBordered target:self action:@selector(showBookContents)];


        [[self navigationItem] setRightBarButtonItem:contentsButton];
        [contentsButton release];

Here is the method that i pass to the button when it’s created:

-(IBAction)showBookContents{
    BookContentsViewController *contentsViewController = [[BookContentsViewController alloc] initWithNibName:@"BookContentsViewController" bundle:nil];

    contentsViewController.selectedBookId = self.selectedBook._id;

    [[self navigationController] pushViewController:contentsViewController animated:YES];

    [contentsViewController release];

}

Here is the class that will be loaded when the use clicks the navbar button:

@interface BookContentsViewController : UIViewController {
    int selectedBookId;
}

@property int selectedBookId;

@end

Here is the implementation for the above class:

@implementation BookContentsViewController

@synthesize selectedBookId;

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

As you can see the @property and @synthesize looks fine. Here is the error i get:

2011-06-13 11:48:42.321 BookApp[22762:207] -[BookDescriptionViewController setSelectedBookId:]: unrecognized selector sent to instance 0x4d9f070
2011-06-13 11:48:42.323 BookApp[22762:207] ** ** Terminating app due to uncaught exception ‘NSInvalidArgumentException’, reason: ‘-[BookDescriptionViewController setSelectedBookId:]: unrecognized selector sent to instance 0x4d9f070’

What can the problem be guys?

Thanks in advance for your patience.

Answer 1

try this

make this selectedBookId NSString and then try.

NSString *selectedBookId;
int selectedBookIdIntegerValue;

@property(nonatomic,retain)NSString selectedBookId; 

Change in this method

-(IBAction)showBookContents{
    BookContentsViewController *contentsViewController = [[BookContentsViewController alloc] initWithNibName:@"BookContentsViewController" bundle:nil];

    contentsViewController.selectedBookId = [NSString stringWithFormat:@"%d",self.selectedBook._id];

    [[self navigationController] pushViewController:contentsViewController animated:YES];

    [contentsViewController release];

}

dont forget to release selectedBookId in dealloc of BookContentsViewController.

since selectedBookId is now NSString
You might need integer value so what you do is
selectedBookIdIntegerValue=[self.selectedBookId intValue];