iOS - 动画背景问题

Question

我正在尝试在屏幕上制作一些元素动画，这里是代码：

  private func setupAnimations() {

    self.emailAddress.alpha = 0
    self.fullName.alpha = 0
    self.password.alpha = 0
    self.confirmPassword.alpha = 0
    self.signUp.alpha = 0
    self.fullName.leftView?.alpha = 0
    self.emailAddress.leftView?.alpha = 0
    self.password.leftView?.alpha = 0
    self.confirmPassword.leftView?.alpha = 0

    self.emailAddress.center.x += self.view.bounds.width-10
    self.fullName.center.x -= self.view.bounds.width-10
    self.password.center.x -= self.view.bounds.width-10
    self.confirmPassword.center.x += self.view.bounds.width-10
    self.signUp.center.y += self.view.bounds.height/2

    UIView.animate(withDuration: 1.7, delay: 0.2, usingSpringWithDamping: 0.7, initialSpringVelocity: 0.5, options: [.allowUserInteraction,.curveEaseInOut], animations: {

        self.emailAddress.alpha = 1
        self.emailAddress.center.x -= self.view.bounds.width-10
        self.view.layoutIfNeeded()

    }, completion: {(completed) in

        if completed {

            UIView.animate(withDuration: 1, animations: {
                self.fullName.leftView?.alpha = 1
                self.emailAddress.leftView?.alpha = 1
                self.password.leftView?.alpha = 1
                self.confirmPassword.leftView?.alpha = 1
            })

        }

    })

    UIView.animate(withDuration: 1.7, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 0.5, options: [.allowUserInteraction,.curveEaseInOut], animations: {

        self.fullName.alpha = 1
        self.fullName.center.x += self.view.bounds.width-10
        self.view.layoutIfNeeded()

    }, completion: {(completed) in

        if completed {

            UIView.animate(withDuration: 1, animations: {
                self.fullName.leftView?.alpha = 1
                self.emailAddress.leftView?.alpha = 1
                self.password.leftView?.alpha = 1
                self.confirmPassword.leftView?.alpha = 1
            })

        }

    })

依此类推......你明白了 - 我将alpha设置为0，将x设置为屏幕外，并设置动画效果＆＃34;到达＆＃34;在屏幕上，它在viewDidLoad（）中被调用。一切都工作了一个月，但最近我检查了这个，问题就在这里：

视频链接：https://streamable.com/lhqvu

背景，即超视图中的UIImage也正在动画，使得超级视图（红色背景）被看到。

任何帮助将不胜感激。提前谢谢。

Answer 1

说到动画，你应该在viewDidAppear而不是viewDidLoad上调用该函数。

Answer 2

在setupAnimations中添加动画viewWillAppear方法，并从self.view.layoutIfNeeded()块中删除usingSpringWithDamping。在故事板中取消选中 safeArea ，并在为superview设置顶级约束时取消选中 约束到边距 ＆amp;设置为零。