Question

I am Using UIImageView in UIScrollView to display Image gallery.
Here is my Code :

    [scrollView1 setBackgroundColor:[UIColor blackColor]];
    [scrollView1 setCanCancelContentTouches:NO];
    scrollView1.indicatorStyle = UIScrollViewIndicatorStyleWhite;
    scrollView1.clipsToBounds = YES;
    scrollView1.scrollEnabled = YES;
    scrollView1.pagingEnabled = YES;


NSUInteger i;
for (i = 0; i <= kNumImages; i++)
{
    imageView.userInteractionEnabled = YES;

    imageName = [NSString stringWithFormat:@"image%d.jpg", i];
    UIImage *image = [UIImage imageNamed:imageName];
    imageView = [[UIImageView alloc] initWithImage:image];
    imageView.contentMode = UIViewContentModeScaleAspectFit;

    CGRect rect = imageView.frame;
    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
    {
        rect.size.height = kScrollObjHeight;
        rect.size.width = kScrollObjWidth;

    }
    else if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
    {
        rect.size.height = kScrollObjHeight_ipad;
        rect.size.width = kScrollObjWidth_ipad;
    }

    imageView.frame = rect;
    imageView.tag = i;
    [scrollView1 addSubview:imageView];
}  

Now i have a save button to save image in library. for that i have to find every image tag on scrolling. I thought it can be possible by detecting a swipe gesture on UIImageView and can get imageView.tag.
I searched many thing but didn’t get much luck. I understand only is it is difficult to recognize swipe in scroll.

I am new to this Gesture things. Can anyone suggest me what to do?
IS there any other way to get particular imagetag ? Or if i have to go with only this Gesturing thins then how ?

Any help would be a great help..!
Thank you.

Answer 1

In my opinion, you have a couple of options:

1.
Add a UISwipeGestureRecognizer to you UIImageView, and in it’s action method change the imageView’s image. For example

UISwipeGestureRecognizer *mySwipeGestureRecognizer = [[UISwipeGestureRecognizer alloc] init];
[mySwipeGestureRecognizer addTarget:self action:@selector(gestureAction:)];
[imageView addGestureRecognizer:mySwipeGestureRecognizer];

-(void)gestureAction:(id)sender  //Here you can also make some validations so to make sure the gesture is finished
{
imageView.image = [UIImage imageNamed:@"someOtherImage"];
}

And then just save the imageView’s image.

2.
The other option would be to set the imageView’s frame according to the number of images and then simpy get the imageView’s X coordinate to calculate what image it is displaying.For example,

for(int i=0; i < numeberOfImages; i++)
{
imageView.frame = CGSizeMake(320*i,0,100,100);
[self.view addSubview:imageView];
}

Then get the scoll’s position to figure out which image is displaying.

Also, I think another way to do this would be to implement the scrollView’s delegate and in the method

- (void)scrollViewDidScroll:(UIScrollView *)scrollView

have a variable to count how many times the user has scrolled and then calculate what image is displaying. Don’t forget to set

scrollView.delegate = self;