在 iOS 13 中向 PDFView 添加轻击手势识别器

Question

我的代码在 iOS 12 中工作。但升级到 iOS 13 后，它就不能工作了。

let pinPointRecognizer = UITapGestureRecognizer(target: self, action: #selector(self.pinPoint(sender:)))
pinPointRecognizer.numberOfTapsRequired = 1
self.pdfView.addGestureRecognizer(pinPointRecognizer)

我已经尝试添加pinPointRecognizer.numberOfTouchesRequired = 2，它可以触发pinPoint()函数。但我想一键触发pinPoint()。

此行为是否会在未来的 iOS 版本中修复？有解决方法吗？

谢谢！

更新：

谢谢大家的回复！很抱歉，我可能没有时间测试你所有的答案。我已更改应用的行为以解决该问题。

我需要在 PDF 文件上添加一个点。我的解决方法是添加一个附加层，在 PDFView 的中心显示一个图钉图标。当用户点击 PDF 视图时，我会在 PDFView 上添加一个图钉图标图像注释。

总之，在我的解决方法中，我仍然使用点击手势识别器。但识别器仅将一个点固定在当前 PDFView 的中心。用户可以放大/缩小并拖动以控制固定点的位置。

Answer 1

let singleTapGesture = UITapGestureRecognizer(target: self, action: #selector(toggleTopBottomView(_:)))
singleTapGesture.numberOfTapsRequired = 1
singleTapGesture.delegate = self
self.pdfContainerView.addGestureRecognizer(singleTapGesture)

@objc func toggleTopBottomView(_ sender: UITapGestureRecognizer){

}


func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
    return true
}

Answer 2

你可以在 Xcode 11、iOS 13 上试试这个

override func viewDidLoad() {
    super.viewDidLoad()

    let tap = UITapGestureRecognizer(target: self, action: #selector(self.handleTap(_:)))

    tap.numberOfTapsRequired = 1

    view.addGestureRecognizer(tap)

    view.isUserInteractionEnabled = true

}

@objc func handleTap(_ sender: UITapGestureRecognizer) {
    print("Tapped")
}

Answer 3

该错误似乎在 iOS 13.2 版本上得到解决。不幸的是，我找不到解决此问题的解决方法。

Answer 4

实际上我安装了 13.2 Beta 时遇到了同样的问题，但是我找到了一个解决方法。我用 13.1 对其进行了测试，它也可以正常工作。当我确实添加了一个点击手势识别器时，它正在 ios 13 上运行，但是它会吞噬链接上的点击。这是我为解决此问题所做的工作： 我覆盖了 PDFView 子类上的 addGestureRecognizer，然后我旋转并找到一个轻按手势 1 触摸（这是由苹果提供的用于处理链接单击的）并创建我想要显示/隐藏的新轻按手势菜单（或您的自定义操作）。我将它添加到 PDFView 并要求苹果内置的失败（第 15 行）。

然后我允许 shouldRecognizeSimultaneouslyWithGesture 让两个轻击手势都能调用 correclty。如果您点击一个链接，我的新链接不会被调用，但如果您不点击一个链接，那么它会完美运行并显示/隐藏我的菜单。我希望这对某人有用！

- (void)addGestureRecognizer:(UIGestureRecognizer *)gestureRecognizer
{  
    if ([gestureRecognizer isKindOfClass:[UITapGestureRecognizer class]])
    {
        UITapGestureRecognizer *tapGest = (UITapGestureRecognizer*)gestureRecognizer;
        if (tapGest.numberOfTapsRequired == 1)
        {
            if (![tapGest isEqual:singleTapGesture])
            {
                if (![self.gestureRecognizers containsObject:singleTapGesture])
                {
                    singleTapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(singleTap:)];
                    [singleTapGesture setNumberOfTapsRequired:1];
                    [singleTapGesture setDelegate:self];
                    [singleTapGesture requireGestureRecognizerToFail:tapGest];
                    [self addGestureRecognizer:singleTapGesture];
                }
            }
        }
    }

    [super addGestureRecognizer:gestureRecognizer];
}

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
  return YES;
}

Answer 5

不幸的是，我找不到在 iOS 13 之前和之后都以相同方式工作的解决方案，并且这篇文章中的解决方案在激活 PDF 中的链接时会触发点击处理程序。

这是我想出的解决方案，根据 iOS 版本不同：

/// Since iOS 13, the way to add a properly functioning tap gesture recognizer on a `PDFView`
/// significantly changed. This class handles the setup depending on the current iOS version.
@available(iOS 11.0, *)
final class PDFTapGestureController: NSObject {
    
    private let tapRecognizer: UITapGestureRecognizer
    
    init(pdfView: PDFView, target: Any?, action: Selector?) {
        assert(pdfView.superview != nil, "The PDFView must be in the view hierarchy")
        
        tapRecognizer = UITapGestureRecognizer(target: target, action: action)

        super.init()
        
        if #available(iOS 13.0, *) {
            // If we add the gesture on the superview on iOS 13, then it will be triggered when
            // taping a link.
            // The delegate will be used to make sure that this recognizer has a lower precedence
            // over the default tap recognizer of the `PDFView`, which is used to handle links.
            tapRecognizer.delegate = self
            pdfView.addGestureRecognizer(tapRecognizer)
            
        } else {
            // Before iOS 13, the gesture must be on the superview to prevent conflicts.
            pdfView.superview?.addGestureRecognizer(tapRecognizer)
        }
    }
    
}

@available(iOS 11.0, *)
extension PDFTapGestureController: UIGestureRecognizerDelegate {

    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        return true
    }
    
    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRequireFailureOf otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        // Make sure we wait for the default PDFView's tap recognizers to fail
        // before triggering our tap handler.
        return (otherGestureRecognizer as? UITapGestureRecognizer)?.numberOfTouchesRequired == tapRecognizer.numberOfTouchesRequired
    }
    
}

像这样使用它：

final class PDFViewController: UIViewController {

    // Holds a reference to make sure it is not garbage-collected.
    private var tapGestureController: PDFTapGestureController?

    open override func viewDidLoad() {
        super.viewDidLoad()
        
        let pdfView = PDFView(frame: view.bounds)
        pdfView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        view.addSubview(pdfView)
        
        tapGestureController = PDFTapGestureController(pdfView: pdfView, target: self, action: #selector(didTap))
    }

    @objc private func didTap(_ gesture: UITapGestureRecognizer) {
        // Necessary to clear the selection with our custom recognizer for iOS 13.
        if pdfView.currentSelection != nil {
            pdfView.clearSelection()
        } else {
            // Your tap handler...
        }
    }