ios - 如何在 iOS 中将生动的文本向上移动？

Question

我想制作一个在 View 中心打招呼的应用程序，等待几秒钟并以动画方式显示到顶部(有点像您在许多应用程序中看到的登录 View )

无论我如何尝试，我都无法使文本保持在 x 轴居中。你能看看我的代码并告诉我错误是什么吗？

谢谢

    // Blur Effect
    var blurEffect = UIBlurEffect(style: UIBlurEffectStyle.Light)
    var blurEffectView = UIVisualEffectView(effect: blurEffect)
    blurEffectView.frame = view.bounds
    view.addSubview(blurEffectView)

    // Vibrancy Effect
    var vibrancyEffect = UIVibrancyEffect(forBlurEffect: blurEffect)
    var vibrancyEffectView = UIVisualEffectView(effect: vibrancyEffect)
    vibrancyEffectView.frame = view.bounds

    // Add label to the vibrancy view

    vibrancyEffectView.contentView.addSubview(vibrantLabel)

    vibrantLabel.textAlignment = NSTextAlignment.Center


    // Add the vibrancy view to the blur view
    blurEffectView.contentView.addSubview(vibrancyEffectView)


    UIView.animateWithDuration(1, delay: 1, options: .CurveEaseIn, animations: {() -> Void in

        self.vibrantLabel.frame = CGRectMake(0, 100, self.vibrantLabel.frame.width, self.vibrantLabel.frame.height)
        }, completion: {(finished: Bool) -> Void in
            self.view.alpha = 1
    })

Answer 1

要解决您的问题，只需在动画期间保留标签的 x 原点即可。请尝试此行:

self.vibrantLabel.frame = CGRectMake(self.vibrantLabel.frame.origin.x, 100, self.vibrantLabel.frame.width, self.vibrantLabel.frame.height)

您将 x 轴上的原点设置为零，因此您的标签动画左对齐到其父 View 。