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Wie kann ich die Bewegung einer Ansicht oder eines Bildes entlang eines gekrümmten Pfads animieren?

Ich entwickle eine Commerce-Anwendung. Wenn ich einen Artikel in den Warenkorb lege, möchte ich einen Effekt erzeugen, bei dem ein Bild des Artikels einem gekrümmten Pfad folgt und auf der Registerkarte "Warenkorb" endet.

Wie kann ich eine Animation eines Bildes entlang einer solchen Kurve erstellen?

80
shilpa

Um das zu erweitern, was Nikolai gesagt hat, ist der beste Weg, dies zu handhaben, die Verwendung der Kernanimation, um die Bewegung des Bildes oder der Ansicht entlang eines Bezierpfads zu animieren. Dies wird mit einer CAKeyframeAnimation erreicht. Zum Beispiel habe ich den folgenden Code verwendet, um ein Bild einer Ansicht in ein Symbol zu animieren, um das Speichern anzuzeigen (wie im video für diese Anwendung zu sehen ist):

Importieren Sie zunächst die QuartzCore-Header-Datei #import <QuartzCore/QuartzCore.h>

UIImageView *imageViewForAnimation = [[UIImageView alloc] initWithImage:imageToAnimate];
imageViewForAnimation.alpha = 1.0f;
CGRect imageFrame = imageViewForAnimation.frame;
//Your image frame.Origin from where the animation need to get start
CGPoint viewOrigin = imageViewForAnimation.frame.Origin;
viewOrigin.y = viewOrigin.y + imageFrame.size.height / 2.0f;
viewOrigin.x = viewOrigin.x + imageFrame.size.width / 2.0f;

imageViewForAnimation.frame = imageFrame;
imageViewForAnimation.layer.position = viewOrigin;
[self.view addSubview:imageViewForAnimation];

// Set up fade out effect
CABasicAnimation *fadeOutAnimation = [CABasicAnimation animationWithKeyPath:@"opacity"];
[fadeOutAnimation setToValue:[NSNumber numberWithFloat:0.3]];
fadeOutAnimation.fillMode = kCAFillModeForwards;
fadeOutAnimation.removedOnCompletion = NO;

// Set up scaling
CABasicAnimation *resizeAnimation = [CABasicAnimation animationWithKeyPath:@"bounds.size"];
[resizeAnimation setToValue:[NSValue valueWithCGSize:CGSizeMake(40.0f, imageFrame.size.height * (40.0f / imageFrame.size.width))]];
resizeAnimation.fillMode = kCAFillModeForwards;
resizeAnimation.removedOnCompletion = NO;

// Set up path movement
CAKeyframeAnimation *pathAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"];
pathAnimation.calculationMode = kCAAnimationPaced;
pathAnimation.fillMode = kCAFillModeForwards;
pathAnimation.removedOnCompletion = NO;
//Setting Endpoint of the animation
CGPoint endPoint = CGPointMake(480.0f - 30.0f, 40.0f);
//to end animation in last tab use 
//CGPoint endPoint = CGPointMake( 320-40.0f, 480.0f);
CGMutablePathRef curvedPath = CGPathCreateMutable();
CGPathMoveToPoint(curvedPath, NULL, viewOrigin.x, viewOrigin.y);
CGPathAddCurveToPoint(curvedPath, NULL, endPoint.x, viewOrigin.y, endPoint.x, viewOrigin.y, endPoint.x, endPoint.y);
pathAnimation.path = curvedPath;
CGPathRelease(curvedPath);

CAAnimationGroup *group = [CAAnimationGroup animation]; 
group.fillMode = kCAFillModeForwards;
group.removedOnCompletion = NO;
[group setAnimations:[NSArray arrayWithObjects:fadeOutAnimation, pathAnimation, resizeAnimation, nil]];
group.duration = 0.7f;
group.delegate = self;
[group setValue:imageViewForAnimation forKey:@"imageViewBeingAnimated"];

[imageViewForAnimation.layer addAnimation:group forKey:@"savingAnimation"];

[imageViewForAnimation release];
153
Brad Larson

Sie können die Center-Eigenschaft eines UIView mithilfe einer CAKeyframeAnimation animieren. Siehe die CoreAnimation -Programmieranleitung.

2
Nikolai Ruhe

Die Art und Weise, CGPath mit UIView.animateKeyframes (Swift 4) zu animieren

private func animateNew() {

   let alphaFrom: CGFloat = 1
   let alphaTo: CGFloat = 0.3
   let sizeFrom = CGSize(width: 40, height: 20)
   let sizeTo = CGSize(width: 80, height: 60)
   let originFrom = CGPoint(x: 40, y: 40)
   let originTo = CGPoint(x: 240, y: 480)

   let deltaWidth = sizeTo.width - sizeFrom.width
   let deltaHeight = sizeTo.height - sizeFrom.height
   let deltaAlpha = alphaTo - alphaFrom

   // Setting default values
   imageViewNew.alpha = alphaFrom
   imageViewNew.frame = CGRect(Origin: originFrom, size: sizeFrom)

   // CGPath setup for calculating points on curve.
   let curvedPath = CGMutablePath()
   curvedPath.move(to: originFrom)
   curvedPath.addQuadCurve(to: originTo, control: CGPoint(x: originFrom.x,  y: originTo.y))
   let path = Math.BezierPath(cgPath: curvedPath, approximationIterations: 10)

   // Calculating timing parameters
   let duration: TimeInterval = 0.7
   let numberOfKeyFrames = 16
   let curvePoints = Math.Easing.timing(numberOfSteps: numberOfKeyFrames, .easeOutQuad)

   UIView.animateKeyframes(withDuration: duration, delay: 0, options: [.calculationModeCubic], animations: {
      // Iterating curve points and adding key frames
      for point in curvePoints {
         let Origin = path.point(atPercentOfLength: point.end)
         let size = CGSize(width: sizeFrom.width + deltaWidth * point.end,
                           height: sizeFrom.height + deltaHeight * point.end)
         let alpha = alphaFrom + deltaAlpha * point.end
         UIView.addKeyframe(withRelativeStartTime: TimeInterval(point.start), relativeDuration: TimeInterval(point.duration)) {
            self.imageViewNew.frame = CGRect(Origin: Origin, size: size)
            self.imageViewNew.alpha = alpha
         }
      }
   }, completion: nil)
}

Datei: Math.Easing.Swift

// Inspired by: RBBAnimation/RBBEasingFunction.m: https://github.com/robb/RBBAnimation/blob/master/RBBAnimation/RBBEasingFunction.m
extension Math { public struct Easing { } }

extension Math.Easing {

   public enum Algorithm: Int {
      case linear, easeInQuad, easeOutQuad, easeInOutQuad
   }

   @inline(__always)
   public static func linear(_ t: CGFloat) -> CGFloat {
      return t
   }

   @inline(__always)
   public static func easeInQuad(_ t: CGFloat) -> CGFloat  {
      return t * t
   }

   @inline(__always)
   public static func easeOutQuad(_ t: CGFloat) -> CGFloat  {
      return t * (2 - t)
   }

   @inline(__always)
   public static func easeInOutQuad(_ t: CGFloat) -> CGFloat  {
      if t < 0.5 {
         return 2 * t * t
      } else {
         return -1 + (4 - 2 * t) * t
      }
   }
}

extension Math.Easing {

   public struct Timing {

      public let start: CGFloat
      public let end: CGFloat
      public let duration: CGFloat

      init(start: CGFloat, end: CGFloat) {
         self.start = start
         self.end = end
         self.duration = end - start
      }

      public func multiplying(by: CGFloat) -> Timing {
         return Timing(start: start * by, end: end * by)
      }
   }

   public static func process(_ t: CGFloat, _ algorithm: Algorithm) -> CGFloat {
      switch algorithm {
      case .linear:
         return linear(t)
      case .easeInQuad:
         return easeInQuad(t)
      case .easeOutQuad:
         return easeOutQuad(t)
      case .easeInOutQuad:
         return easeInOutQuad(t)
      }
   }

   public static func timing(numberOfSteps: Int, _ algorithm: Algorithm) -> [Timing] {
      var result: [Timing] = []
      let linearStepSize = 1 / CGFloat(numberOfSteps)
      for step in (0 ..< numberOfSteps).reversed() {
         let linearValue = CGFloat(step) * linearStepSize
         let processedValue = process(linearValue, algorithm) // Always in range 0 ... 1
         let lastValue = result.last?.start ?? 1
         result.append(Timing(start: processedValue, end: lastValue))
      }
      result = result.reversed()
      return result
   }
}

Datei: Math.BezierPath.Swift. Schauen Sie sich das an SO Antwort: https://stackoverflow.com/a/50782971/1418981

 enter image description here

0
Vlad

Swift 4-Version ähnlich dem ObjC-Beispiel aus der ursprünglichen Antwort.

class KeyFrameAnimationsViewController: ViewController {

   let sampleImage = ImageFactory.image(size: CGSize(width: 160, height: 120), fillColor: .blue)

   private lazy var imageView = ImageView(image: sampleImage)
   private lazy var actionButton = Button(title: "Animate").autolayoutView()

   override func setupUI() {
      view.addSubviews(imageView, actionButton)
      view.backgroundColor = .gray
   }

   override func setupLayout() {
      LayoutConstraint.withFormat("|-[*]", actionButton).activate()
      LayoutConstraint.withFormat("V:|-[*]", actionButton).activate()
   }

   override func setupHandlers() {
      actionButton.setTouchUpInsideHandler { [weak self] in
         self?.animate()
      }
   }

   private func animate() {

      imageView.alpha = 1
      let isRemovedOnCompletion = false

      let sizeFrom = CGSize(width: 40, height: 20)
      let sizeTo = CGSize(width: 80, height: 60)
      let originFrom = CGPoint(x: 40, y: 40)
      let originTo = CGPoint(x: 240, y: 480)

      imageView.frame = CGRect(Origin: originFrom, size: sizeFrom)
      imageView.layer.position = originFrom

      // Set up fade out effect
      let fadeOutAnimation = CABasicAnimation(keyPath: "opacity")
      fadeOutAnimation.toValue = 0.3
      fadeOutAnimation.fillMode = kCAFillModeForwards
      fadeOutAnimation.isRemovedOnCompletion = isRemovedOnCompletion

      // Set up scaling
      let resizeAnimation = CABasicAnimation(keyPath: "bounds.size")
      resizeAnimation.toValue = sizeTo
      resizeAnimation.fillMode = kCAFillModeForwards
      resizeAnimation.isRemovedOnCompletion = isRemovedOnCompletion

      // Set up path movement
      let pathAnimation = CAKeyframeAnimation(keyPath: "position")
      pathAnimation.calculationMode = kCAAnimationPaced;
      pathAnimation.fillMode = kCAFillModeForwards;
      pathAnimation.isRemovedOnCompletion = isRemovedOnCompletion

      // Setting Endpoint of the animation to end animation in last tab use
      let curvedPath = CGMutablePath()
      curvedPath.move(to: originFrom)
      // About curves: https://www.bignerdranch.com/blog/core-graphics-part-4-a-path-a-path/
      curvedPath.addQuadCurve(to: originTo, control: CGPoint(x: originFrom.x,  y: originTo.y))
      pathAnimation.path = curvedPath

      let group = CAAnimationGroup()
      group.fillMode = kCAFillModeForwards
      group.isRemovedOnCompletion = isRemovedOnCompletion
      group.animations = [fadeOutAnimation, pathAnimation, resizeAnimation]
      group.duration = 0.7
      group.setValue(imageView, forKey: "imageViewBeingAnimated")

      imageView.layer.add(group, forKey: "savingAnimation")
   }
}
0
Vlad