如何点击缩放和双击在iOS中缩小？

我正在开发一个应用程序来显示UIImages通过使用UIScrollView画廊，我的问题是，如何点击zoom和双击zoom ，如何处理UIScrollView时工作。

Answer 1

你需要在你的viewController中实现UITapGestureRecognizer – docs

 - (void)viewDidLoad { [super viewDidLoad]; // what object is going to handle the gesture when it gets recognised ? // the argument for tap is the gesture that caused this message to be sent UITapGestureRecognizer *tapOnce = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapOnce:)]; UITapGestureRecognizer *tapTwice = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapTwice:)]; // set number of taps required tapOnce.numberOfTapsRequired = 1; tapTwice.numberOfTapsRequired = 2; // stops tapOnce from overriding tapTwice [tapOnce requireGestureRecognizerToFail:tapTwice]; // now add the gesture recogniser to a view // this will be the view that recognises the gesture [self.view addGestureRecognizer:tapOnce]; [self.view addGestureRecognizer:tapTwice]; } 

基本上这个代码是说，当一个UITapGesture注册在self.view方法tapOnce或tapTwice将被调用self取决于如果它的单击或双击。 因此，您需要将这些tap方法添加到您的UIViewController ：

 - (void)tapOnce:(UIGestureRecognizer *)gesture { //on a single tap, call zoomToRect in UIScrollView [self.myScrollView zoomToRect:rectToZoomInTo animated:NO]; } - (void)tapTwice:(UIGestureRecognizer *)gesture { //on a double tap, call zoomToRect in UIScrollView [self.myScrollView zoomToRect:rectToZoomOutTo animated:NO]; } 

希望有所帮助

Answer 2

Swift 3.0版本在双击时放大两倍。

 @IBOutlet weak var scrollView: UIScrollView! @IBOutlet weak var imageView: UIImageView! 

某处（通常在viewDidLoad中）：

 let tapRecognizer = UITapGestureRecognizer(target: self, action: #selector(onDoubleTap(gestureRecognizer:))) tapRecognizer.numberOfTapsRequired = 2 scrollView.addGestureRecognizer(tapRecognizer) 

处理器：

 func onDoubleTap(gestureRecognizer: UITapGestureRecognizer) { let scale = min(scrollView.zoomScale * 2, scrollView.maximumZoomScale) if scale != scrollView.zoomScale { let point = gestureRecognizer.location(in: imageView) let scrollSize = scrollView.frame.size let size = CGSize(width: scrollSize.width / scale, height: scrollSize.height / scale) let origin = CGPoint(x: point.x - size.width / 2, y: point.y - size.height / 2) scrollView.zoom(to:CGRect(origin: origin, size: size), animated: true) print(CGRect(origin: origin, size: size)) } }