斯威夫特3：我如何捏缩放和旋转的UIImageView？

Question

我真的在努力寻找在线教程，以及已回答的问题（我曾尝试他们，他们似乎不工作）。我有一个UIImageView，我有我的观点的中心。我目前能够点击并拖动这个地方我想在屏幕上。我希望能够捏缩放和旋转了这一观点。如何实现这一目标？我曾尝试下面旋转代码，但它似乎没有工作？任何帮助将是一个巨大的帮助，并标记为答案。感谢大伙们。

    import UIKit

class DraggableImage: UIImageView {

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {

        self.backgroundColor = .blue

    }

    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {

        self.backgroundColor = .green

    }

    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
        if let touch = touches.first {
            let position = touch.location(in: superview)
            center = CGPoint(x: position.x, y: position.y)
        }
    }

}

class CVController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .white

        let rotateGesture = UIRotationGestureRecognizer(target: self, action: #selector(rotateAction(sender:)))
        firstImageView.addGestureRecognizer(rotateGesture)

        setupViews()
    }

    func rotateAction(sender: UIRotationGestureRecognizer) {
        let rotatePoint = sender.location(in: view)
        let firstImageView = view.hitTest(rotatePoint, with: nil)
        firstImageView?.transform = (firstImageView?.transform.rotated(by: sender.rotation))!
        sender.rotation = 0
    }

    let firstImageView: DraggableImage = {
        let iv = DraggableImage()
        iv.backgroundColor = .red
        iv.isUserInteractionEnabled = true
        return iv
    }()

    func setupViews() {
        view.addSubview(firstImageView)

        let firstImageWidth: CGFloat = 50
        let firstImageHeight: CGFloat = 50

        firstImageView.frame = CGRect(x: (view.frame.width / 2) - firstImageWidth / 2, y: (view.frame.height / 2) - firstImageWidth / 2, width: firstImageWidth, height: firstImageHeight)
    }

}

Answer 1

你在你的代码中的一些问题。首先，你需要的UIGestureRecognizerDelegate添加到您的视图控制器，并让它成为你手势识别委托。并添加shouldRecognizeSimultaneously方法并返回true。第二个应用规模，当你需要保存改造捏开始时和在它上面的应用规模：

class DraggableImageView: UIImageView {
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        backgroundColor = .blue
    }
    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        backgroundColor = .green
    }
    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
        if let position = touches.first?.location(in: superview){
            center = position
        }
    }
}

---

class ViewController: UIViewController, UIGestureRecognizerDelegate {

    var identity = CGAffineTransform.identity

    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .white
        setupViews()

        let pinchGesture = UIPinchGestureRecognizer(target: self, action: #selector(scale))
        let rotationGesture = UIRotationGestureRecognizer(target: self, action: #selector(rotate))

        pinchGesture.delegate = self
        rotationGesture.delegate = self

        view.addGestureRecognizer(pinchGesture)
        view.addGestureRecognizer(rotationGesture)
    }
    let firstImageView: DraggableImageView = {
        let iv = DraggableImageView()
        iv.backgroundColor = .red
        iv.isUserInteractionEnabled = true
        return iv
    }()

    func setupViews() {
        view.addSubview(firstImageView)
        let firstImageWidth: CGFloat = 50
        let firstImageHeight: CGFloat = 50
        firstImageView.frame = CGRect(x: view.frame.midX - firstImageWidth / 2, y: view.frame.midY - firstImageWidth / 2, width: firstImageWidth, height: firstImageHeight)
    }
    @objc func scale(_ gesture: UIPinchGestureRecognizer) {
        switch gesture.state {
        case .began:
            identity = firstImageView.transform
        case .changed,.ended:
            firstImageView.transform = identity.scaledBy(x: gesture.scale, y: gesture.scale)
        case .cancelled:
            break
        default:
            break
        }
    }
    @objc func rotate(_ gesture: UIRotationGestureRecognizer) {
        firstImageView.transform = firstImageView.transform.rotated(by: gesture.rotation)
    }
    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        return true
    }
}