我想让uiviews的alpha动画化，但我似乎做不到。它的行为怪异，并表示错误的运行UI更改不推荐在后台线程上运行，但我不知道如何使它运行在主线程上。谁能帮帮我吗？我相信它跳过了第一个uiview.animate块，并在没有任何动画的情况下执行第二个块中的内容。
函数animateSemaphore（）{
circleRed.alpha = 0.2
circleOrange.alpha = 0.2
circleGreen.alpha = 1
let dispatchSemaphore = DispatchSemaphore(value: 0)
let dispatchQueue = DispatchQueue.global(qos: .background)
dispatchQueue.async {
UIView.animate(withDuration: 0.5, delay: 5, options: .curveEaseInOut) {
self.circleOrange.alpha = 1
self.circleGreen.alpha = 0.2
} completion: { (_) in
print("1")
dispatchSemaphore.signal()
}
dispatchSemaphore.wait()
UIView.animate(withDuration: 0.5, delay: 3, options: .curveEaseInOut) {
self.circleOrange.alpha = 0.2
self.circleRed.alpha = 1
} completion: { (_) in
dispatchSemaphore.signal()
}
dispatchSemaphore.wait()
UIView.animate(withDuration: 0.5, delay: 5, options: .curveEaseInOut) {
self.circleOrange.alpha = 1
} completion: { (_) in
dispatchSemaphore.signal()
}
dispatchSemaphore.wait()
UIView.animate(withDuration: 0.5, delay: 1, options: .curveEaseInOut) {
self.circleOrange.alpha = 0.2
self.circleRed.alpha = 0.2
self.circleGreen.alpha = 1
} completion: { (_) in
self.animateSemaphore()
}
}
}
您需要在主线程中插入任何与UI/Animate相关的代码，而不是在后台队列中
func animateSemaphore() {
circleRed.alpha = 0.2
circleOrange.alpha = 0.2
circleGreen.alpha = 1
UIView.animate(withDuration: 0.5, delay: 5, options: .curveEaseInOut) {
self.circleOrange.alpha = 1
self.circleGreen.alpha = 0.2
} completion: { (_) in
UIView.animate(withDuration: 0.5, delay: 3, options: .curveEaseInOut) {
self.circleOrange.alpha = 0.2
self.circleRed.alpha = 1
} completion: { (_) in
UIView.animate(withDuration: 0.5, delay: 5, options: .curveEaseInOut) {
self.circleOrange.alpha = 1
} completion: { (_) in
UIView.animate(withDuration: 0.5, delay: 1, options: .curveEaseInOut) {
self.circleOrange.alpha = 0.2
self.circleRed.alpha = 0.2
self.circleGreen.alpha = 1
} completion: { (_) in
}
}
}
}
}
或者玩延迟而不是嵌套动画
func animateSemaphore() {
circleRed.alpha = 0.2
circleOrange.alpha = 0.2
circleGreen.alpha = 1
UIView.animate(withDuration: 0.5, delay: 5, options: .curveEaseInOut) {
self.circleOrange.alpha = 1
self.circleGreen.alpha = 0.2
} completion: { (_) in
print("1")
}
UIView.animate(withDuration: 0.5, delay: 8.5, options: .curveEaseInOut) {
self.circleOrange.alpha = 0.2
self.circleRed.alpha = 1
} completion: { (_) in
}
UIView.animate(withDuration: 0.5, delay: 14, options: .curveEaseInOut) {
self.circleOrange.alpha = 1
} completion: { (_) in
}
UIView.animate(withDuration: 0.5, delay: 15.5, options: .curveEaseInOut) {
self.circleOrange.alpha = 0.2
self.circleRed.alpha = 0.2
self.circleGreen.alpha = 1
} completion: { (_) in
}
}
