我正在构建一个类似flashcard的应用程序,我正在使用一个库KolodaView:
https://github.com/Yalantis/Koloda
我有这个扩展,它返回一个UIView作为闪卡的前面:
extension StudyViewController: KolodaViewDataSource {
func kolodaNumberOfCards(koloda:KolodaView) -> UInt {
return UInt(memories.count)
}
func koloda(koloda: KolodaView, viewForCardAtIndex index: UInt) -> UIView {
return UIImageView(image: memories[Int(index)].frontImage)
}
func koloda(koloda: KolodaView, viewForCardOverlayAtIndex index: UInt) -> OverlayView? {
return NSBundle.mainBundle().loadNibNamed("OverlayView",owner: self, options: nil)[0] as? OverlayView
}
}
我希望能够通过点击将视图转换为后视图:
func koloda(koloda: KolodaView, didSelectCardAtIndex index: UInt) {
let frontView: UIView = koloda as KolodaView
let backView: UIView = UIImageView(image: memories[Int(index)].backImage)
if showingFront == true {
UIView.transitionFromView(frontView, toView: backView, duration: 1, options: UIViewAnimationOptions.TransitionCrossDissolve, completion: nil)
} else {
UIView.transitionFromView(backView, toView: frontView, duration: 1, options: UIViewAnimationOptions.TransitionCrossDissolve, completion: nil)
showingFront = false
}
}
过渡是成功的,但在完成后,闪卡将从KolodaView变成一个巨大的UIView
如何将KolodaView转换为花药KolodaView?
最佳答案 我没有使用过KolodaView,所以我的答案对于手头的问题更为通用.
两种方法
一个.您当前方法的变体(Hackish方式)
由于库不公开对显示的imageView的引用,因此您首先需要维护内部的imageView集以供以后使用.
private var myImageViews: [Int: UIImageView] = [:]
func koloda(koloda: KolodaView, viewForCardAtIndex index: UInt) -> UIView {
let imageView = UIImageView(image: memories[Int(index)].frontImage)
myImageViews[Int(index)] = imageView
return imageView
}
使用当前方法设置动画视图,并使用完成块更新原始图像的最终状态.
UIView.transitionFromView(frontView,
toView: backView,
duration: duration,
options: [.TransitionCrossDissolve, .ShowHideTransitionViews],
completion: { [weak self] (finished: Bool) in
let imageView = myImageViews[Int(index)]
imageView.image = memories[Int(index)].frontImage
frontView.hidden = false
backView.hidden = true
backView.removeFromSuperview()
})
湾在datasource方法中返回自定义视图,并在didSelectCardAtIndex中切换其内部状态
private var myCustomViews: [Int: MyCustomView] = [:]
func koloda(koloda: KolodaView, viewForCardAtIndex index: UInt) -> UIView {
let customView = MyCustomView(frontImage: memories[Int(index)].frontImage,
backImage: memories[Int(index)].backImage)
myCustomViews[Int(index)] = customView
return customView
}
func koloda(koloda: KolodaView, didSelectCardAtIndex index: UInt) {
let customView = myCustomViews[Int(index)]
customView.toggleFrontBackState()
}
在这种情况下,toggleFrontBackState的实现将包含初始实现的代码(customView.showingFront,transitionFromView).如果您需要更多说明,请与我们联系.
编辑
class MyCustomView: UIView {
private(set) lazy var frontView: UIImageView = self.makeFrontView()
private(set) lazy var backView: UIImageView = self.makeBackView()
var showingFront: Bool = false
init(frontImage: UIImage?, backImage: UIImage?){
super.init(frame: CGRectZero)
frontView.image = frontImage
backView.image = backImage
backView.hidden = true
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func toggleFrontBackState() {
if showingFront {
UIView.transitionFromView(frontView, toView: backView, duration: 1,
options: [.TransitionCrossDissolve, .ShowHideTransitionViews], completion: nil)
} else {
UIView.transitionFromView(backView, toView: frontView, duration: 1,
options: [.TransitionCrossDissolve, .ShowHideTransitionViews] , completion: nil)
}
showingFront = !showingFront
}
func makeFrontView() -> UIImageView {
return UIImageView()
}
func makeBackView() -> UIImageView {
return UIImageView()
}
}