How would I implement pinch to close functionality in UIScrollView? - ios

Question

When the user zooms far enough out of the image by pinching out, then releases, I want it to close the UIImageView/scroll view, basically exiting the picture viewer.
How would I go about doing this? scrollViewDidEndZooming is called after it animates back into place, so I can't use that, and none of the other delegate methods seem helpful.

Answer 1

i have create this effect for one of my app, dont forget to set delegate of your scrollview.
you need to update the private method with your pinch gesture(thats all)
code for .h file
#import <UIKit/UIKit.h>
#interface ImageViewerController : UIViewController<UIScrollViewDelegate>
// The scroll view used for zooming.
#property (weak, nonatomic) IBOutlet UIScrollView *scrollView;
// The image view that displays the image.
#property (weak, nonatomic) IBOutlet UIImageView *imageView;
// The image that will be shown.
#property (strong, nonatomic) NSString *imageUrlString;
#end
code for .m
#import "ImageViewerController.h"
#interface HNImageViewerController ()
- (IBAction)handleSingleTap:(UIButton*)tapGestureRecognizer;
#end
#implementation ImageViewerController
- (void)viewDidLoad {
[super viewDidLoad];
[self.imageView setImage:[UIImage imageNamed:#"placeholder-image"]];
self.scrollView.delegate=self;
}
- (BOOL)prefersStatusBarHidden {
return YES;
}
#pragma mark - UIScrollViewDelegate methods
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return self.imageView;
}
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {
if (self.scrollView.zoomScale == self.scrollView.minimumZoomScale) {
[self dismissViewControllerAnimated:YES completion:nil];
}
}
#pragma mark - Private methods
- (IBAction)handleSingleTap:(UIButton *)tapGestureRecognizer {
[self dismissViewControllerAnimated:YES completion:nil];
}