当我在viewDidLoad()方法内添加以下代码的时候发现程序运行时不会有动画过度效果,而是直接跳到了最后。
let x = (self.view.bounds.size.width - 268) / 2 scanImage.frame = CGRectMake(x, 106, 268, 2) scanImage.contentMode = UIViewContentMode.ScaleAspectFill self.view.addSubview(scanImage) UIView.animateWithDuration(2, delay: 0, options: UIViewAnimationOptions.Repeat, animations: { () -> Void in self.scanImage.frame = CGRectMake(x,372, 268, 2) }, completion: nil)
通过度娘后有网友说要把该代码块放到viewDidAppear(animated: Bool)方法内,试以一下果然有动画效果了。这到底是为什么啊?who can tell me why?
时间: 2024-10-16 14:20:04