Question

我希望为视图构建一个漂亮的背景，图像淡出＆amp;但是，我也希望动画不要停止。

我已经在使用它了：

backgroundUIImageView.animationImages =
[UIImage(named:"testimage1"), UIImage(named:"testimage2")]
backgroundUIImageView.animationDuration = 10
backgroundUIImageView.animationRepeatCount = 0
backgroundUIImageView.startAnimating()

问题：转换没有褪色

我也试过这个：

        var UIImage1=UIImage(named:"testimage1")
        var UIImage2=UIImage(named:"testimage2")
        var crossFade = CABasicAnimation(keyPath:"contents")
        crossFade.duration = 5.0
        crossFade.fromValue = UIImage1.CGImage
        crossFade.toValue = UIImage2.CGImage
        self.backgroundUIImageView.layer.addAnimation(crossFade, forKey:"animateContents")
        self.backgroundUIImageView.image = UIImage2

问题：动画没有重复，代码真的很难看。在我看来不安全..

有人会有关于如何做到这一点的任何想法/代码示例吗？

Answer 1

我不知道如何在SWIFT中编写它，但我使用此代码段。要重复，您应该添加选项UIViewAnimationOptionAutoreverse和UIViewAnimationOptionRepeat

    UIImage * toImage = [[UIImage alloc] initWithContentsOfFile:imagePath];
    [UIView transitionWithView:self.imageView
                      duration:0.8f
                       options:UIViewAnimationOptionTransitionCrossDissolve
                    animations:^{
                        self.imageView.image = toImage;
                    } completion:nil];

Answer 2

我只需要自己做这件事。我使用了NSTimer和CA crossfade的组合。每次你的计时器开火，你都会得到一个很好的淡入淡出过渡。调整动画的长度和计时器间隔以设置动画的速度。

func startAnimatingLoadingImage() {
    self.timer = NSTimer.scheduledTimerWithTimeInterval(0.3, target:self, selector: Selector("flipImage"), userInfo: nil, repeats: true)

}

和这个

func flipImage() {
    let cell1 = UIImage(named: "dots1")!
    let cell2 = UIImage(named: "dots2")!
    let cell3 = UIImage(named: "dots3")!
    let cell4 = UIImage(named: "dots4")!
    let cells = [cell1, cell2, cell3, cell4]
    let numCells = cells.count - 1
    let currentImage = cells[currentCell]
    var nextImage: UIImage

    if currentCell == numCells {
        nextImage = cells[0]
        self.currentCell = 0
    } else {
        let x = currentCell + 1
        nextImage = cells[x]
        self.currentCell = x
    }

    let crossFade = CABasicAnimation(keyPath:"contents")
    crossFade.duration = 0.25
    crossFade.fromValue = currentImage.CGImage
    crossFade.toValue = nextImage.CGImage
    self.loadingView.layer.addAnimation(crossFade, forKey:"animateContents")
    self.loadingView.image = nextImage
}

淡出UIImageView转换

2 个答案: