UIPinchGestureRecognizer in UIView is not working properly

Question

I am trying to do zoom-in and zoom-out in a UIView using UIPinchGestureRecognizer. But when I do pinch on my trackpad, it is not recognising the pinch and the control is not going to my twoFingerPinch function. I am using the following code.

- (void)viewDidLoad {
//.......
UIPinchGestureRecognizer *twoFingerPinch = [[UIPinchGestureRecognizer alloc]
                      initWithTarget:self
                      action:@selector(twoFingerPinch:)];
    [myview addGestureRecognizer:twoFingerPinch];
//.....
}

- (void)twoFingerPinch:(UIPinchGestureRecognizer *)recognizer
{
    NSLog(@"Pinch scale: %f", recognizer.scale);
    if (recognizer.scale >1.0f && recognizer.scale < 2.5f) {
        CGAffineTransform transform = CGAffineTransformMakeScale(recognizer.scale, recognizer.scale//);
        myview.transform = transform;
    }
}

Why it is not recognising the pinch from trackpad? Is there any other method to do the same?

For zoomin/zoomout in Simulator you need to use the "option" key buttonalong with your trackpad for dragging. — Santosh, Aug 08 '16 at 13:52
Use `Alt` or `Option` key for pinch gesture instead of track pad. — Nirav D, Aug 08 '16 at 13:52
@Raul : No. Why we need Option button to do pinch? Can't we do it directly from trackpad/mouse? — itzmebibin, Aug 08 '16 at 13:52
Try using `recognizer.scale >1` and `recogniser.scale<1` for zoom in and zoom out. — Onur Tuna, Aug 08 '16 at 13:55

score 1 · Answer 1 · edited May 23 '17 at 12:22

1

First click on the Option button. you will get 2 gray spots which you can move using the mouse or trackpad. in older versions you need to press shift+option.

for more details check this.

edited May 23 '17 at 12:22

Community

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1

answered Aug 08 '16 at 13:56

Raul

11
8

Got it. Thanks. It was not the error in my code. I was not knowing about the use of Option button to do pinching. – itzmebibin Aug 08 '16 at 13:59

score 1 · Answer 2 · answered Aug 08 '16 at 13:56

1

Make sure that userInteractionEnabled is set to yes for your myview,

 myview.userInteractionEnabled = YES;

answered Aug 08 '16 at 13:56

Ketan Parmar

27,092
9
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UIPinchGestureRecognizer in UIView is not working properly

2 Answers2