如何在iOS中点击缩放和双击缩小？

我正在开发一个应用程序，通过使用

UIScrollView

来显示

UIImages

的图库，我的问题是，如何点击

zoom

并双击

zoom

，处理

UIScrollView

时，它是如何工作的？您需要在viewController中实现UITapgestureRecognitizer-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，这段代码是说，当在

self.view

中注册

uitappostation

时，将在

self

中调用方法tapOnce或tapttweeds，具体取决于它是单次点击还是双次点击。因此，您需要将这些点击方法添加到您的

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];
}

---

希望这对双击两次缩放的Swift 4.0版本有所帮助

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

某处（通常在viewDidLoad中）：

处理程序：

@objc 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))
    }
}

---

非常感谢您的回答，我将测试它，并尽快报告。是否可能Webview识别触摸侧边Webview中的链接[tapOnce RequiremeTestureRecognitizerToFail:TapTworth]；这正是我想要的。谢谢这在Swift 5/Xcode 12.4中仍然以同样的方式工作。要使用另一个双击（和动画）缩小，您只需将以下内容添加到

else

部分：

scrollView.setZoomScale（scrollView.minimumZoomScale，动画：true）

@objc 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))
    }
}