闪烁一张图片1秒(淡入淡出图片)

Question

我正在尝试制作一个图片显示1秒，然后再次淡出到原始图片。这是我的尝试；

@IBOutlet var button1: UIButton!
var button1flashing = false

override func viewDidLoad() {
    super.viewDidLoad()


if !button1flashing {
            flashbutton1()
        } else {
            stopflashingbutton1()
        }
}


func flashbutton1() {
    button1flashing = true

    UIButton.animateWithDuration(1.0, animations: {

        self.button1.setImage(UIImage(named: "code1"), forState: .Normal)

        }, completion: {Bool in
    })
}


func stopflashingbutton1() {

    UIButton.animateWithDuration(1.0, animations: {

        self.button1.setImage(UIImage(named: "code2"), forState: .Normal)

        }, completion: nil)
}

问题:该按钮在视图加载后立即设置为图像"code1“(没有动画)，即使它在故事板中设置为"code2”。此外，它不会淡出到图像"code2“(不执行func stopflashingbutton1)

Answer 1

使用此函数(您需要显示和隐藏按钮)：

func flashButton(button: UIButton, imageName: String, completion: (finished: Bool) -> Void) {

    UIView.animateWithDuration(1.0, animations: {
        button.alpha = 0
        }, completion: {finished in
            button.setImage(UIImage(named: imageName), forState: .Normal)
            UIButton.animateWithDuration(1.0, animations: {
                button.alpha = 1
                }, completion: {finished in
                    completion(finished: finished)
            })
    })
}

func flashButton(button: UIButton, imageName: String) {

    UIView.animateWithDuration(1.0, animations: {
        button.alpha = 0
        }, completion: {finished in
            button.setImage(UIImage(named: imageName), forState: .Normal)
            UIButton.animateWithDuration(1.0, animations: {
                button.alpha = 1
                })
    })
}

在你的viewDidLoad中

override func viewDidLoad() {
    super.viewDidLoad()
    flashButton(button1, imageName: "code1") { (finished) -> Void in
            self.flashButton(self.button1, imageName: "code2")
        }
    }
}

Answer 2

将alpha设置为0.1，然后设置为1.0，两者之间的间隔为秒。这会产生动画效果。