Image size resets to original after performing pich using UIPichGestureRecognizer in iphone - uiscrollview

Question

I have one view controller in which I have added UIScrollView & UIImageView programatically. I have added UIPichGestureRecognizer to the UIImageView. My UIImageView is added to UIScrollView as a subview.
My problem is when I try to pinch the image , it zoom in. But when I release the touches from screen it again come to its default size. I can not find the error in code. Please help me.
Below is my code
- (void)createUserInterface {
scrollViewForImage = [[UIScrollView alloc]initWithFrame:CGRectMake(20.0f, 60.0f, 280.0f, 200.0f)];
scrollViewForImage.userInteractionEnabled = YES;
scrollViewForImage.multipleTouchEnabled = YES;
scrollViewForImage.backgroundColor = [UIColor redColor];
scrollViewForImage.autoresizesSubviews = YES;
scrollViewForImage.maximumZoomScale = 1;
scrollViewForImage.minimumZoomScale = .50;
scrollViewForImage.clipsToBounds = YES;
scrollViewForImage.delegate = self;
scrollViewForImage.bouncesZoom = YES;
scrollViewForImage.contentMode = UIViewContentModeScaleToFill;
[self.contentView addSubview:scrollViewForImage];
imageView = [[UIImageView alloc]initWithFrame:CGRectMake(0.0f, 0.0f, 280.0f, 200.0f)];
[imageView setBackgroundColor:[UIColor clearColor]];
imageView.userInteractionEnabled = YES;
imageView.multipleTouchEnabled = YES;
UIPinchGestureRecognizer *pinchRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:#selector(pinch:)];
[pinchRecognizer setDelegate:self];
[imageView addGestureRecognizer:pinchRecognizer];
//[self.contentView addSubview:imageView];
[self.scrollViewForImage addSubview:imageView];
scrollViewForImage.contentSize = CGSizeMake(imageView.frame.size.width , imageView.frame.size.height);
}
-(UIView *) viewForZoomingInScrollView:(UIScrollView *)inScroll {
return imageView;
}
-(void)pinch:(id)sender {
[self.view bringSubviewToFront:[(UIPinchGestureRecognizer*)sender view]];
if([(UIPinchGestureRecognizer*)sender state] == UIGestureRecognizerStateEnded) {
lastScale = 1.0;
return;
}
CGFloat scale = 1.0 - (lastScale - [(UIPinchGestureRecognizer*)sender scale]);
CGAffineTransform currentTransform = [(UIPinchGestureRecognizer*)sender view].transform;
CGAffineTransform newTransform = CGAffineTransformScale(currentTransform, scale, scale);
[[(UIPinchGestureRecognizer*)sender view] setTransform:newTransform];
lastScale = [(UIPinchGestureRecognizer*)sender scale];
}

Answer 1

From what I can see the problem lies here:
scrollViewForImage.maximumZoomScale = 1;
You are setting the maximum zoom scale of the image to 1 x its full size. This means once you finish pinching the image, it will scale back to 1 x its size.
If you want to be able to zoom the image to a larger size, try settings this value to be higher than 1. e.g.
scrollViewForImage.maximumZoomScale = 3;