使用 UIGestureRecognizer 旋转瓶子

Question

我现在正在使用此代码在点击按钮时旋转瓶子：

@IBAction func spinButton(sender: AnyObject) {
        let rotateView = CABasicAnimation()
        let randonAngle = arc4random_uniform(360) + 720
        rotateView.fromValue = 0
        rotateView.toValue = Float(randonAngle) * Float(M_PI) / 180.0
        rotateView.duration = 3
        rotateView.delegate = self
        rotateView.repeatCount = 0
        rotateView.removedOnCompletion = false
        rotateView.fillMode = kCAFillModeForwards
        rotateView.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseOut)
        bottleImageView.layer.addAnimation(rotateView, forKey: "transform.rotation.z")
    }

但是如何使用手势旋转按钮？所以 harder/faster 我移动手指，瓶子旋转得越快

Answer 1

对此的简单回答是...使用 UIScrollView.

从我这里的问题... Loop UIScrollView but continue decelerating

将它翻译成 Swift 是微不足道的，但这里...

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    //make the content size really big so that the targetOffset of the deceleration will never be met.

    scrollView.contentSize = CGSize(width: CGRectGetWidth(scrollView.frame) * 100.0, height: CGRectGetHeight(scrollView.frame))
    //set the contentOffset of the scroll view to a point in the center of the contentSize.
    scrollView.setContentOffset(CGPoint(CGRectGetWidth(scrollView.frame) * 50, 0), animated: false)
}

func rotateImageView() {
    //Calculate the percentage of one "frame" that is the current offset.

    // each percentage of a "frame" equates to a percentage of 2 PI Rads to rotate
    let minOffset = CGRectGetWidth(scrollView.frame) * 50.0
    let maxOffset = CGRectGetWidth(scrollView.frame) * 51.0

    let offsetDiff = maxOffset - minOffset

    let currentOffset = scrollView.contentOffset.x - minOffset

    let percentage = currentOffset / offsetDiff

    arrowView.transform = CGAffineTransformMakeRotation(M_PI * 2 * percentage)
}

func scrollViewDidScroll(scrollView: UIScrollView) {
    //the scrollView moved so update the rotation of the image
    rotateImageView()
}

func scrollViewDidEndDecelerating(scrollView: UIScrollView) {
    //the scrollview stopped moving.
    //set the content offset back to be in the middle
    //but make sure to keep the percentage (used above) the same
    //this ensures the arrow is pointing in the same direction as it ended decelerating

    let diffOffset = scrollView.contentOffset.x

    while diffOffset >= CGRectGetWidth(scrollView.frame) {
        diffOffset = diffOffset - CGRectGetWidth(scrollView.frame)
    }

    scrollView.setContentOffset(CGPoint(x: CGRectGetWidth(scrollView.frame) * 50 + diffOffset, y: 0), animated:false)
}

在这个例子中，我的旋转视图是 arrowView。 scrollView 和 arrowView 都应该是视图控制器视图的子视图。 scrollView 中不应包含任何内容。

N.B。这是在浏览器中完成的，因此可能存在一些语法问题。您可能还需要将一些数字转换为 CGFloat 等...

此外，能够从 Objective-C 进行翻译对于任何 iOS 开发人员来说都是必不可少的。数百万个应用程序是使用 Objective-C 编写的。语法可能略有不同，但所有 API 都是相同的。

学习如何做到这一点是每个 iOS 开发人员都应该做的事情。

Answer 2

使用UIPanGestureRecognizer。创建一个 panGestureRecognizer 并将其添加到瓶子的超级视图中并实现它的委托。它有velocityInView、translationInView等变量。当用户完成平移时，使用它们来计算旋转的角度、速度和持续时间。

Answer 3

我已经成功地创建了一个示例应用程序，它在中心有一个视图，您可以使用 UIRotationGestureRecognizer 旋转它，并且旋转速度会根据旋转速度而受到影响。为此，我使用了 UIDynamics：

class ViewController: UIViewController {

@IBOutlet weak var sampleView: UIView!

var animator: UIDynamicAnimator?

override func viewDidLoad() {
    super.viewDidLoad()

    setupRotationGesture()

}

override func viewDidAppear(animated: Bool) {

    animator = UIDynamicAnimator(referenceView: self.view)

    let sampleViewBehavior = UIDynamicItemBehavior(items: [self.sampleView])
    sampleViewBehavior.allowsRotation = true // view can rotate
    animator?.addBehavior(sampleViewBehavior)

    let anchoredSuperViewBehavior = UIDynamicItemBehavior(items: [self.view])
    anchoredSuperViewBehavior.anchored = true
    animator?.addBehavior(anchoredSuperViewBehavior)

    // Attachment between the sample view and super view at center anchor point.

    let attachment = UIAttachmentBehavior.pinAttachmentWithItem(self.sampleView, attachedToItem: self.view, attachmentAnchor: CGPointMake(self.view.center.x + 1, self.view.center.y + 1))
    animator?.addBehavior(attachment)
}


// MARK: - Rotation Gesture -

func setupRotationGesture(){

    let rotationGesture = UIRotationGestureRecognizer(target: self, action: #selector(handleRotationGesture(_:)))
    self.sampleView.addGestureRecognizer(rotationGesture)
}

func handleRotationGesture(gesture: UIRotationGestureRecognizer){

    if gesture.state == .Ended {

        let push = UIPushBehavior(items: [self.sampleView], mode: .Instantaneous)

        push.magnitude = abs(50.5 * gesture.velocity)
        let transform = self.sampleView.transform
        push.angle = atan2(transform.b, transform.a);
        animator?.addBehavior(push)
    }

}
 }

当您运行时，您将能够根据旋转手势的速度旋转视图。

使用 UIGestureRecognizer 旋转瓶子

Spin bottle with UIGestureRecognizer

xcode

uiimageview

uigesturerecognizer

ios

swift