我在滚动视图中添加了两个视图控制器,并在这两个视图控制器上设置了动画,但这些动画只应在显示vc时调用。然而,当第一个vc显示时,两个动画都被执行。
func setUpScrollView() {
for i in 0..<2 {
let vc = NewViewController()
self.addChildViewController(vc)
scrollView.addSubview(vc.view)
vc.didMove(toParentViewController: self)
var frame: CGRect = vc.view.frame
frame.origin.x = self.view.frame.width * CGFloat(i)
vc.view.frame = frame
self.scrollView.contentSize = CGSize(width: self.view.frame.width * CGFloat(2), height: self.view.frame.size.height)
}
}
新建视图控制器
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
print("calling animation") //this is called twice immediatley after for loop, but only shows one vc.
}