ios - 如何在 iOS 中为不断闪烁的灯光制作动画？

Question

我正在尝试构建一个带有 NEON 的 iOS 应用程序，它会像真实的 NEON 一样随机且持续闪烁。

我不太确定如何让动画不断重复，我也不确定如何让它自动且永远运行。我把它放在 viewDidLoad 中，但我不确定那是否真的是放置它的最佳位置？

    UIImageView.animate(withDuration: 0.05, delay: 5.0, options: .repeat, animations: {
        UIImageView.animate(withDuration: 0.05, delay: 2.0, animations: {
            self.Aletter.alpha = 0.2
        }) { (_) in
            UIImageView.animate(withDuration: 0.05, delay: 0.0, animations: {
                self.Aletter.alpha = 1.0
            }, completion: { (_) in
                UIImageView.animate(withDuration: 0.05, delay: 2.0, animations: {
                    self.Aletter.alpha = 0.6
                }, completion: { (_) in
                    UIImageView.animate(withDuration: 0.05, delay: 0.0, animations: {
                        self.Aletter.alpha = 1.0
                    }, completion: { (_) in
                        UIImageView.animate(withDuration: 0.05, delay: 0.0, animations: {
                            self.Aletter.alpha = 0.6
                        }, completion: { (_) in
                            UIImageView.animate(withDuration: 0.05, delay: 0.0, animations: {
                                self.Aletter.alpha = 1.0
                            }, completion: { (_) in
                                UIImageView.animate(withDuration: 0.05, delay: 0.0, animations: {
                                    self.Aletter.alpha = 0.6
                                }, completion: { (_) in
                                    UIImageView.animate(withDuration: 0.05, delay: 0.0, animations: {
                                        self.Aletter.alpha = 1.0
                                    }, completion: { (_) in

                                    })
                                })
                            })
                        })
                    })
                })
            })
        }
    })

此代码将运行我的一系列闪烁，但只会运行一次。我需要它持续运行。

Answer 1

正如 Matt 在评论部分所建议的那样，您可以使用如下内容:

private func flicker() { [weak self] in
    UIView.animate(withDuration: 0.05, animations: {
        self?.Aletter.alpha = CGFloat.random(in: 0.1...1.0)
    }) { _ in
        // When this round of animations completes call the same method again to start the animations again with a new random value for alpha.
        self?.flicker()
    }
}

只需在 viewDidLoad() 中调用 flicker()。 flicker 方法为 Aletter View 启动一个具有随机 alpha 值的动画，当此动画完成时它会再次调用自身。

作为旁注，请为您的变量使用小写首字母，Aletter 应该是 aletter 或 aLetter，具体取决于上下文。