Pinch Zoom on Two ImageViews in Single ScrollView on IOS

Question

I am doing a project in which i need two imageviews in single Scrollview with zooming options. UIScrollView allows one view to make zoom easily. But my problem is not like that. I have two imageviews side by side in the scroll view.When I try to zoom the images its not working Is there is any option to zoom two image views at the same time.Please suggest me some idea.

Thanks in advance

so your problem is that when you zoom, your two images should be zoom...Am i right??? — NiravPatel, Aug 23 '13 at 05:09
i think you should add two imageview in one view and in the viewForZooming method you should return thats view — Sunny Shah, Aug 23 '13 at 05:24
Put your `UIImageView`s in two separate `UIScrollView` and put those `UIScrollView` in your `UIScrollView` and set tag for those and use the delegate to zoom it as in the @Sunnyshah mentioned after checking the tag for `UIScrollView`. Hope it will work. — Exploring, Aug 23 '13 at 06:07

score 3 · Answer 1 · edited Aug 29 '13 at 11:47

Here is code for Zooming two images in single scrollview

I have added two UIImageView's in One UIView and then I have added the UIView to UIScrollView. Following is my code :

- (void)viewDidLoad {
    [super viewDidLoad];
    self.vwImages = [[UIView alloc]initWithFrame:CGRectMake(0, 0,100,200)];

    // 1
    UIImage *image = [UIImage imageNamed:@"imgBaskteBall2.jpeg"];
    UIImageView *imageView1 = [[UIImageView alloc] initWithImage:image];
    imageView1.frame = CGRectMake(0,0,100,100);
    [self.vwImages addSubview:imageView1];

    UIImage *image2 = [UIImage imageNamed:@"imgBaskteBall1.jpeg"];
    UIImageView *imageView2 = [[UIImageView alloc] initWithImage:image2];
    imageView2.frame = CGRectMake(0, 100, 100, 100);
    [self.vwImages  addSubview:imageView2];

    // 2

    [self.scrollView addSubview:self.vwImages];

    self.scrollView.contentSize = self.vwImages.frame.size;

    // 3
    UITapGestureRecognizer *doubleTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(scrollViewDoubleTapped:)];
    doubleTapRecognizer.numberOfTapsRequired = 2;
    doubleTapRecognizer.numberOfTouchesRequired = 1;
    [self.scrollView addGestureRecognizer:doubleTapRecognizer];

    UITapGestureRecognizer *twoFingerTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(scrollViewTwoFingerTapped:)];
    twoFingerTapRecognizer.numberOfTapsRequired = 1;
    twoFingerTapRecognizer.numberOfTouchesRequired = 2;
    [self.scrollView addGestureRecognizer:twoFingerTapRecognizer];
}


- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];

    // 4
    CGRect scrollViewFrame = self.scrollView.frame;
    CGFloat scaleWidth = scrollViewFrame.size.width / self.scrollView.contentSize.width;
    CGFloat scaleHeight = scrollViewFrame.size.height / self.scrollView.contentSize.height;
    CGFloat minScale = MIN(scaleWidth, scaleHeight);
    self.scrollView.minimumZoomScale = minScale;

    // 5
    self.scrollView.maximumZoomScale = 10.0f;
    self.scrollView.zoomScale = minScale;

    // 6
    [self centerScrollViewContents];
}


- (void)centerScrollViewContents {
    CGSize boundsSize = self.scrollView.bounds.size;
    CGRect contentsFrame = self.vwImages.frame;

    if (contentsFrame.size.width < boundsSize.width) {
        contentsFrame.origin.x = (boundsSize.width - contentsFrame.size.width) / 2.0f;
    } else {
        contentsFrame.origin.x = 0.0f;
    }

    if (contentsFrame.size.height < boundsSize.height) {
        contentsFrame.origin.y = (boundsSize.height - contentsFrame.size.height) / 2.0f;
    } else {
        contentsFrame.origin.y = 0.0f;
    }

    self.vwImages.frame = contentsFrame;
}

- (void)scrollViewDoubleTapped:(UITapGestureRecognizer*)recognizer {
    // 1
    CGPoint pointInView = [recognizer locationInView:self.imageView];

    // 2
    CGFloat newZoomScale = self.scrollView.zoomScale * 1.5f;
    newZoomScale = MIN(newZoomScale, self.scrollView.maximumZoomScale);

    // 3
    CGSize scrollViewSize = self.scrollView.bounds.size;

    CGFloat w = scrollViewSize.width / newZoomScale;
    CGFloat h = scrollViewSize.height / newZoomScale;
    CGFloat x = pointInView.x - (w / 2.0f);
    CGFloat y = pointInView.y - (h / 2.0f);

    CGRect rectToZoomTo = CGRectMake(x, y, w, h);

    // 4
    [self.scrollView zoomToRect:rectToZoomTo animated:YES];
}

- (void)scrollViewTwoFingerTapped:(UITapGestureRecognizer*)recognizer {
    // Zoom out slightly, capping at the minimum zoom scale specified by the scroll view
    CGFloat newZoomScale = self.scrollView.zoomScale / 1.5f;
    newZoomScale = MAX(newZoomScale, self.scrollView.minimumZoomScale);
    [self.scrollView setZoomScale:newZoomScale animated:YES];
}

- (UIView*)viewForZoomingInScrollView:(UIScrollView *)scrollView {
    // Return the view that you want to zoom
    return self.vwImages;
}

- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
    // The scroll view has zoomed, so you need to re-center the contents
    [self centerScrollViewContents];
}

`CGPoint pointInView = [recognizer locationInView:self.imageView];` How to get Imageview ? — user2526811, Oct 30 '15 at 06:55

score 3 · Answer 2 · edited Dec 18 '16 at 08:18

3

Make object of UIView as container for example viewContainer

[viewContainer addSubView:imageView1];

[viewContainer addSubView:imageView2];

[scrollView addSubView:viewContainer];

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
    return viewContainer;
}

Add

edited Dec 18 '16 at 08:18

Praveen Gowda I V

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answered Aug 29 '13 at 11:52

SachinVsSachin

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score 0 · Answer 3 · edited May 23 '17 at 12:24

0

You can use this

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView 
{
    return [self.scrollView.subviews objectAtIndex:0];
}

the viewForZoomingInScrollView delegate method return the object at Index 0.

From Properly zooming a UIScrollView that contains many subviews

edited May 23 '17 at 12:24

Community

1
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answered Aug 23 '13 at 05:24

IronManGill

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score 0 · Answer 4 · answered Aug 23 '13 at 05:25

0

add both the imageView in the view and replace this method

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
    return view;
}

answered Aug 23 '13 at 05:25

Sunny Shah

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Pinch Zoom on Two ImageViews in Single ScrollView on IOS

4 Answers4