[英]Swift: animateWithDuration behavior
我已经制作了简单的文本和按钮动画,可以从屏幕外移动到屏幕中间,但事实并非如此。 它从屏幕转到屏幕外。 基本上,动画是相反的。
我已经看到其他应用程序可以用相同的代码来工作,所以我不知道出什么问题了。 :(
这是代码:
import UIKit
class ViewController: UIViewController {
@IBOutlet weak var welcomeText: UILabel!
@IBOutlet weak var worksText: UILabel!
@IBOutlet weak var loginButton: UIButton!
@IBOutlet weak var signUp: UIButton!
@IBOutlet weak var socialLog: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewWillAppear(animated: Bool) {
welcomeText.alpha = 0.0
worksText.alpha = 0.0
loginButton.alpha = 0.0
signUp.alpha = 0.0
socialLog.alpha = 0.0
welcomeText.center.x -= view.bounds.width
worksText.center.x -= view.bounds.width
socialLog.center.x -= view.bounds.width
signUp.center.x -= view.bounds.width
}
override func viewDidAppear(animated: Bool) {
self.welcomeText.fadeIn()
UIView.animateWithDuration(0.7, delay: 0.1, options: .CurveEaseOut, animations: {
self.welcomeText.center.x += self.view.bounds.width
self.view.layoutIfNeeded()
}, completion: nil)
self.worksText.fadeIn()
UIView.animateWithDuration(0.7, delay: 0.5, options: .CurveEaseOut, animations: {
self.worksText.center.x += self.view.bounds.width
self.view.layoutIfNeeded()
}, completion: nil)
self.socialLog.fadeIn()
UIView.animateWithDuration(0.7, delay: 0.3, options: .CurveEaseOut, animations: {
self.socialLog.center.x += self.view.bounds.width
self.view.layoutIfNeeded()
}, completion: nil)
self.signUp.fadeIn()
UIView.animateWithDuration(0.7, delay: 0.7, options: .CurveEaseOut, animations: {
self.signUp.center.x += self.view.bounds.width
self.signUp.alpha = 0.5
self.view.layoutIfNeeded()
}, completion: nil)
}
}
extension UIView {
func fadeIn(duration: NSTimeInterval = 0.5, delay: NSTimeInterval = 0.0, completion: ((Bool) -> Void) = {(finished: Bool) -> Void in}) {
UIView.animateWithDuration(duration, delay: delay, options: UIViewAnimationOptions.CurveEaseIn, animations: {
self.alpha = 1.0
}, completion: completion) }
func fadeOut(duration: NSTimeInterval = 0.5, delay: NSTimeInterval = 0.0, completion: (Bool) -> Void = {(finished: Bool) -> Void in}) {
UIView.animateWithDuration(duration, delay: delay, options: UIViewAnimationOptions.CurveEaseIn, animations: {
self.alpha = 0.0
}, completion: completion)
}
}
要调试此视图,将需要有关视图从何处开始的信息。 但是,我强烈建议不要对此类动画使用+ =或-=。 在您体验时,它的行为是不可预测的,因为它完全取决于当前状态。
相反,您可以在viewWillAppear中执行此操作: *view*.center.x = -(*view*.frame.width / 2)
在viewDidAppear中执行: view .center.x = 此处需要的任何值
同样,所有这些的最新方法是使用约束并设置约束动画,而不是框架。
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