IBAction is not working with UITapGestureRecognizer - objective-c

Question

I am working on an application where i need to zoom a UIView on click of UITapGestureRecognizer and want to perform a IBAction while zooming and after zooming. Is this possible?. Please give me a small example of it.

Answer 1

- (void)viewDidLoad
{
[super viewDidLoad];
UITapGestureRecognizer *tapGestureRecognizer = [[UITapGestureRecognizer alloc]initWithTarget:self action:#selector(handleDoubleTap:)];
tapGestureRecognizer.numberOfTapsRequired = 2;
[self.scrollContainer addGestureRecognizer:tapGestureRecognizer];
}
- (void)handleDoubleTap:(UIGestureRecognizer *)recognizer
{
if(isAlreadyZoomed)
{
CGPoint Pointview = [recognizer locationInView:recognizer.view];
CGFloat newZoomscal = 3.0;
CGSize scrollViewSize = self.scrollContainer.bounds.size;
CGFloat width = scrollViewSize.width/newZoomscal;
CGFloat height = scrollViewSize.height /newZoomscal;
CGFloat xPos = Pointview.x-(width/2.0);
CGFloat yPos = Pointview.y-(height/2.0);
CGRect rectTozoom = CGRectMake(xPos, yPos, width, height);
[self.scrollContainer zoomToRect:rectTozoom animated:YES];
[self.scrollContainer setZoomScale:3.0 animated:YES];
isAlreadyZoomed = NO;
}
else
{
[self.scrollContainer setZoomScale:1.0 animated:YES];
isAlreadyZoomed = YES;
}
}

Answer 2

IBAction are just regular methods that returns void and take 0 or 1 argument only.
You can call them in code as you would call any other king of methods.
UITapGestureRecognizer are design to call an IBAction method while triggered. You can set that from InterfaceBuilder or in code
for example the following code
UITapGestureRecognizer * tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:#selector(handleTap:)];
tap.numberOfTapsRequired = 2;
[imageView addGestureRecognizer:[tap cop]];
will called this methods when the user doubleTap the imageView
- (void) handleTap:(UITapGestureRecognizer *)sender;
in this methods, you can pretty much do whatever you need:
managing your subviews,
calling other methods etc...
However, if you plan an zooming in and out, I would strongly recommand the usage of the UIScrollView class instead of the UIView class.
Cheers

Answer 3

hi i hope below would give u a idea.....
UITapGestureRecognizer *tap2 = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(scrollViewDoubleTapped:)];
tap2.numberOfTapsRequired = 2;
[self.view addGestureRecognizer:tap2];
- (void) scrollViewDoubleTapped:(UITapGestureRecognizer *)sender
{
scrollZoomAdjust.zoomScale=2.0f;// set your required Zoom scale
// scrollZoomAdjust is the scroll view that contain the image within it
}
the above code was not tested