问题
In ViewController.Swift I managed to make a box animate from one point to another. I thought it would be easy to loop this so the box will animate to one point and then animate back to its original position and then loop again. I have managed to move the object to a position and in "complete" move it back again, but that doesn't make i loop. How can this be achieved?
I thought maybe this could work but i honestly don't know:
let boxmoves = [CGRect(x: 120, y: 220, width: 100, height: 100), CGRect(x: 120, y: 120, width: 100, height: 100)]
for boxmove in boxmoves {
coloredSquare.frame = boxmove
}
How could I center it based on the device-width (I assume there are some math involved?)?
My code:
let coloredSquare = UIView()
coloredSquare.backgroundColor = UIColor.blueColor()
coloredSquare.frame = CGRect(x: 120, y: 120, width: 100, height: 100)
self.view.addSubview(coloredSquare)
// found repeate but this will not animate as I want.
//UIView.animateWithDuration(2.0, delay: 0.2, options: UIViewAnimationOptions.Repeat, animations: {
UIView.animateWithDuration(2.0, animations: {
coloredSquare.frame = CGRect(x: 120, y: 220, width: 100, height: 100)
}, completion: { finished in
UIView.animateWithDuration(2.0, animations: {
coloredSquare.frame = CGRect(x: 120, y: 120, width: 100, height: 100)
})
})
回答1:
No need to do the completion block approach, just use the animation options argument:
updated for Swift 3.0
UIView.animate(withDuration: 2.0, delay: 0, options: [.repeat, .autoreverse], animations: {
coloredSquare.frame = CGRect(x: 120, y: 220, width: 100, height: 100)
}, completion: nil)
If for any reason you want to stop the animation later, just use:
coloredSquare.layer.removeAllAnimations()
回答2:
UIView.animate(withDuration: 3.0,
delay: 0.0,
options: [.curveLinear, .repeat],
animations: { () -> Void in
coloredSquare.frame = CGRect(x: 120, y: 220, width: 100, height: 100)
}, completion: { (finished: Bool) -> Void in
})
来源：https://stackoverflow.com/questions/27660540/uiview-animatewithduration-swift-loop-animation