Question

I am a newbie to iphone development and i am doing a simple app for practice. In that app,there is only one view that has an image on it. I want to be able to swipe left or right and have the first image go out of the view and the second image to come in. The images are different and I want it to look like they are connected. I need it to be able to change the image or restart after a series of swipes. I am doing this using ScrollView only.

This is the code:

ViewController.h

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController <UIScrollViewDelegate>
{
    UIImageView *imgView;
    UIScrollView *scrollView;
}

@property (nonatomic,retain)IBOutlet UIImageView *imgView;
@property (nonatomic, retain) IBOutlet UIScrollView *scrollView;

//- (id)initWithPageNumber:(int)page;

@end

viewcontroller.m

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

@synthesize imgView,scrollView;

- (void)viewDidLoad
{
    NSArray *images = [[NSArray alloc] initWithObjects:@"1.jpeg",@"2.jpeg",@"3.jpeg", nil];
    for (int i = 0; i < images.count; i++) {
        CGRect frame;
        frame.origin.x = self.scrollView.frame.size.width * i;
        frame.origin.y = 0;
        frame.size = self.scrollView.frame.size;
        imgView = [images objectAtIndex:i];
        imgView.frame = frame;
        [scrollView addSubview:imgView];
    }

    self.scrollView.contentSize = CGSizeMake(self.scrollView.frame.size.width * images.count, self.scrollView.frame.size.height);

    [super viewDidLoad];

}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
- (void)viewDidUnload {
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
    self.scrollView = nil;
}



@end

I am not still able to scroll the images. Not sure where my error is? Moreover, it now gives me this exception:

Exception:

[__NSCFConstantString setFrame:]: unrecognized selector sent to instance 0x49b8
2012-10-24 16:49:42.411 SwipeImages[3330:c07] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFConstantString setFrame:]: unrecognized selector sent to instance 0x49b8'
*** First throw call stack:
(0x1c8d012 0x10cae7e 0x1d184bd 0x1c7cbbc 0x1c7c94e 0x2718 0xf3817 0xf3882 0x42a25 0x42dbf 0x42f55 0x4bf67 0x213b 0xf7b7 0xfda7 0x10fab 0x22315 0x2324b 0x14cf8 0x1be8df9 0x1be8ad0 0x1c02bf5 0x1c02962 0x1c33bb6 0x1c32f44 0x1c32e1b 0x107da 0x1265c 0x1d7d 0x1ca5)
libc++abi.dylib: terminate called throwing an exception

Answer 1

you are placing strings in array put image objects in that. i.e.

NSArray *images = [[NSArray alloc] initWithObjects:[UIImage imageNamed:@"1.jpeg"],[UIImage imageNamed:@"2.jpeg"],[UIImage imageNamed:@"3.jpeg"], nil];

also here is a suggestion. use ping images instead of jpeg. Inform me when you’ve done that.

EDIT:

the other thing is here

imgView = [images objectAtIndex:i];

you are passing image to an imageview object which in fact now becomes an image object. And image has no frame property. Do this

 imgView.image = [images objectAtIndex:i];