在同一个 UIImageView 上缩放和固定

Question

我在UIScrollView 中有一个UIImageView，用于允许用户放大图像。这部分没有问题。为此，我使用以下代码：

func viewForZooming(in scrollView: UIScrollView) -> UIView? {
    return self.imageView
}

此外，用户可以将某些位置固定在同一图像中。我正在使用以下代码固定图像，也没有问题。

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
    let touch = touches.first!
    let location = touch.location(in: self.imageView)
    let touchedRect = CGRect(x: location.x - 10, y: location.y - 10, width: 20, height: 20)

    let touchedInCourt = touchedRect.intersects(self.imageView.bounds)
    switch touchedInCourt {
    case true:
        if self.imageView.subviews.count > 0 {
            var flagForIntersect = false
            for subview in self.imageView.subviews {
                let subviewFrame = subview.frame
                if subviewFrame.intersects(touchedRect) {
                    subview.removeFromSuperview()
                    flagForIntersect = true
                }
            }
            if !flagForIntersect {
                addDot(withLocation: location, toPhoto: self.imageView)
            }
        } else {
            addDot(withLocation: location, toPhoto: self.imageView)
        }
    case false: break
    }
}

func addDot(withLocation location: CGPoint, toPhoto photo: UIImageView) {
    let frame = CGRect(x: location.x - 15, y: location.y - 15, width: 30, height: 30)
    let tempImageView = UIImageView(frame: frame)
    tempImageView.image = UIImage(named: "Blue Dot")
    photo.addSubview(tempImageView)
}

在同一 UIImageView 中使用这两个部分会导致问题。

如果scrollView.userInteractionEnable = true， zoom 有效，但 touchesEnded 函数未调用。 另一方面，如果 scrollView.userInteractionEnable = false touchesEnded 函数已调用但缩放无效。

touch.location(in:) 函数对我非常有用，因此我不想从UITouch 切换到UITapGestureRecognizer。

有没有办法使用UITouch 来完成这两个部分？

Answer 1

好的，我解决了这个问题。

原来UITapGestureRecognizer 也有.location(in:) 功能。

对于那些遇到同样问题的人，我在下面添加了工作代码。

let longPressRecognizer = UILongPressGestureRecognizer(target: self, action: #selector(longPressed))
longPressRecognizer.minimumPressDuration = 0.5
longPressRecognizer.delaysTouchesBegan = true
longPressRecognizer.delegate = self
self.imageView.addGestureRecognizer(longPressRecognizer)

@objc func longPressed(sender: UILongPressGestureRecognizer) {
    if sender.state == UIGestureRecognizer.State.ended {
        let location = sender.location(in: self.imageView)
        let touchedRect = CGRect(x: location.x - 10, y: location.y - 10, width: 20, height: 20)

        let touchedInCourt = touchedRect.intersects(self.imageView.bounds)
        switch touchedInCourt {
        case true:
            if self.imageView.subviews.count > 0 {
                var flagForIntersect = false
                for subview in self.imageView.subviews {
                    let subviewFrame = subview.frame
                    if subviewFrame.intersects(touchedRect) {
                        subview.removeFromSuperview()
                        flagForIntersect = true
                    }
                }
                if !flagForIntersect {
                    addDot(withLocation: location, toPhoto: self.imageView)
                }
            } else {
                addDot(withLocation: location, toPhoto: self.imageView)
            }
        case false: break
        }
    }
}

我使用了UILongPressGestureRecognizer，但UITapGestureRecognizer 也可以。