我正在尝试为我的应用创建背景动画。我想要实现的部分目标是：
1）图像（从阵列中选择的随机颜色/形状）随机出现在视图上。 2）然后大小迅速增加（从不可见到可见）。 3）然后将在旋转的同时沿给定方向缓慢移动10秒钟。 4）然后，它将缩小到不可见的大小，并从视图中删除。
我发现的是，形状将在步骤1和2中正确显示。然后，形状将在动画/步骤3开始时跳到屏幕上的随机位置（以下代码中的transition3）。当它移动时，它的大小也会减小。然后，对于第4步，它会跳回到第1步和第2步的原始位置，然后按预期缩小屏幕。
我无法为自己的生活弄清楚这里发生的事情。我希望我没有错过令人尴尬的显而易见的事情。
在此先感谢您的帮助！
class BackgroundAnimation {
func animation(animationView: UIView) {
let colourArray = [
UIColor(red:0.99, green:0.80, blue:0.05, alpha:1.0),
UIColor(red:0.06, green:0.22, blue:0.29, alpha:1.0),
UIColor(red:0.95, green:0.18, blue:0.30, alpha:1.0),
UIColor(red:0.35, green:0.77, blue:0.92, alpha:1.0),
UIColor(red:0.95, green:0.61, blue:0.19, alpha:1.0)
]
let imageArray = [
"Cross",
"Circle",
"Halfmoon",
"Square",
"Triangle"
]
//Animation constants
let initialDimensions = 10
let pathLength: CGFloat = 100
let pathDuration = 10
let scaleFactor: CGFloat = 5
let scaleDuration = 1
//Select the random image and random colour that is to be animated.
let image = UIImage(named: imageArray[Int.random(in: 0...imageArray.count - 1)])
let imageView = UIImageView(image: image)
imageView.image = imageView.image?.withRenderingMode(.alwaysTemplate)
imageView.tintColor = colourArray[Int.random(in: 0...colourArray.count - 1)]
imageView.contentMode = .scaleAspectFit
imageView.frame = CGRect(x: 0, y: 0, width: initialDimensions, height: initialDimensions)
animationView.insertSubview(imageView, at: 0)
//create a random start location and angle of direction
let startPointX = CGFloat.random(in: 0...animationView.frame.width)
let startPointY = CGFloat.random(in: 0...animationView.frame.height)
let pathAngle = CGFloat.random(in: 0...(CGFloat.pi * 2))
imageView.center = CGPoint(x: startPointX, y: startPointY)
//Calculate the endpoint from path angle and length
let translationX = pathLength * sin(pathAngle)
let tanslationY = -(pathLength * cos(pathAngle))
//Define the transitions for the aniamtion
var transition1 = CGAffineTransform.identity
transition1 = transition1.scaledBy(x: scaleFactor, y: scaleFactor)
var transition2 = CGAffineTransform.identity
transition2 = transition2.translatedBy(x: translationX, y: tanslationY)
transition2 = transition2.rotated(by: CGFloat.random(in: CGFloat.pi * 1/4 ... CGFloat.pi * 3/4))
var transition3 = CGAffineTransform.identity
transition3 = transition3.scaledBy(x: 0.001, y: 0.001)
UIView.animate(withDuration: TimeInterval(scaleDuration), delay: 0, options: .beginFromCurrentState, animations: {
imageView.transform = transition1
}, completion: {finished in
UIView.animate(withDuration: TimeInterval(pathDuration), delay: 0, options: .beginFromCurrentState, animations: {
imageView.transform = transition2
}, completion: { finished in
UIView.animate(withDuration: TimeInterval(scaleDuration), delay: 0, options: .beginFromCurrentState, animations: {
imageView.transform = transition3
}, completion: { finished in
imageView.removeFromSuperview()
})
})
})
}
}
答案 0 :(得分：0)
使用imageView.center或imageView.frame.origin更改位置
imageView.frame.origin = CGPoint(x: translationX, y: tanslationY)
但是您应该计算目的地，然后将frame.origin设置为目的地
答案 1 :(得分：0)
参考Ehsan的有帮助的答复：
这已解决了移动问题，但是当我尝试在第二个动画块中应用旋转时，imageView变得越来越小。下面更新了代码：
class BackgroundAnimation {
func animation(animationView: UIView) {
let colourArray = [
UIColor(red:0.99, green:0.80, blue:0.05, alpha:1.0),
UIColor(red:0.06, green:0.22, blue:0.29, alpha:1.0),
UIColor(red:0.95, green:0.18, blue:0.30, alpha:1.0),
UIColor(red:0.35, green:0.77, blue:0.92, alpha:1.0),
UIColor(red:0.95, green:0.61, blue:0.19, alpha:1.0)
]
let imageArray = [
"Cross",
"Circle",
"Halfmoon",
"Square",
"Triangle"
]
//Animation constants
let initialDimensions = 10
let pathLength: CGFloat = 100
let pathDuration = 10
let scaleFactor: CGFloat = 3
let scaleDuration = 1
//Select the random image and random colour that is to be animated.
let image = UIImage(named: imageArray[Int.random(in: 0...imageArray.count - 1)])
let imageView = UIImageView(image: image)
imageView.image = imageView.image?.withRenderingMode(.alwaysTemplate)
imageView.tintColor = colourArray[Int.random(in: 0...colourArray.count - 1)]
imageView.contentMode = .scaleAspectFit
imageView.frame = CGRect(x: 0, y: 0, width: initialDimensions, height: initialDimensions)
animationView.insertSubview(imageView, at: 0)
//create a random start location and angle of direction
let startPointX = CGFloat.random(in: 0...animationView.frame.width * 0.9)
let startPointY = CGFloat.random(in: 0...animationView.frame.height * 0.9)
let pathAngle = CGFloat.random(in: 0...(CGFloat.pi * 2))
imageView.center = CGPoint(x: startPointX, y: startPointY)
//Calculate the endpoint from path angle and length
let translationX = pathLength * sin(pathAngle)
let translationY = (pathLength * cos(pathAngle))
let endPointX = startPointX + translationX
let endPointY = startPointY + translationY
//Define the transitions for the aniamtion
var transition1 = CGAffineTransform.identity
transition1 = transition1.scaledBy(x: scaleFactor, y: scaleFactor)
var transition2 = CGAffineTransform.identity
transition2 = transition2.rotated(by: CGFloat.random(in: CGFloat.pi * 1/4 ... CGFloat.pi * 3/4))
var transition3 = CGAffineTransform.identity
transition3 = transition3.scaledBy(x: 0.001, y: 0.001)
UIView.animate(withDuration: TimeInterval(scaleDuration), delay: 0, options: .beginFromCurrentState, animations: {
imageView.transform = transition1
}, completion: {finished in
UIView.animate(withDuration: TimeInterval(pathDuration), delay: 0.5, options: [.beginFromCurrentState, .curveLinear], animations: {
imageView.frame.origin = CGPoint(x: endPointX, y: endPointY)
imageView.transform = transition2
}, completion: { finished in
UIView.animate(withDuration: TimeInterval(scaleDuration), delay: 0.5, options: .beginFromCurrentState, animations: {
imageView.transform = transition3
}, completion: { finished in
imageView.removeFromSuperview()
})
})
})
}
}