在阅读了一些SO和其他文章(见下文)之后,当您将多个图像加载到动画数组中时,最好的内存管理方法是什么?
http://www.alexcurylo.com/2009/01/13/imagenamed-is-evil/
这是我的目标:
- 创建动画数组(见下面的代码)
- 在动画播放后清除缓存并加载另一个动画(反复执行,你懂的 :)
正如苹果公司所述https://forums.developer.apple.com/thread/17888
使用UIImage(named: imageName)
会缓存图像,但在我的情况下,在连续播放2-3个动画后,iOS终止了应用程序(操作系统没有响应低内存警告,而是终止了应用程序-请参见下面的代码结尾)
我不想缓存图像,我们可以选择以下两种方式之一:
- 每次动画完成后清除内存,然后加载新的动画;或者
- 当用户移动到新场景时清除内存
这是我的代码:
// create the Animation Array for each animation
func createImageArray(total: Int, imagePrefix: String) -> [UIImage]{
var imageArray: [UIImage] = []
for imageCount in 0..<total {
let imageName = "\(imagePrefix)-\(imageCount).png"
let image = UIImage(named: imageName)! // here is where we need to address memory and not cache the images
//let image = UIImage(contentsOfFile: imageName)! // maybe this?
imageArray.append(image)
}
return imageArray
}
// here we set the animate function values
func animate(imageView: UIImageView, images: [UIImage]){
imageView.animationImages = images
imageView.animationDuration = 1.5
imageView.animationRepeatCount = 1
imageView.startAnimating()
}
// Here we call the animate function
animation1 = createImageArray(total: 28, imagePrefix: "ImageSet1")
animation2 = createImageArray(total: 53, imagePrefix: "ImageSet2")
animation3 = createImageArray(total: 25, imagePrefix: "ImageSet3")
func showAnimation() {
UIView.animate(withDuration: 1, animations: {
animate(imageView: self.animationView, images: self.animation1)
}, completion: { (true) in
//self.animationView.image = nil // Maybe we try the following?
//self.animationView.removeFromSuperview()
//self.animationView = nil
})
}
根据 Stack Overflow 的回答,这似乎是防止图像被缓存的最佳方法,但在我的代码中似乎不起作用:
let image = UIImage(contentsOfFile: imageName)!
我也尝试过这个方法,但似乎也不起作用:
func applicationDidReceiveMemoryWarning(application: UIApplication) {
NSURLCache.sharedURLCache().removeAllCachedResponses()
}
我还尝试了在完成块中使用以下文章(removeFromSuperview),但我也无法使其工作(请参见上面的代码):
https://www.hackingwithswift.com/example-code/uikit/how-to-animate-views-using-animatewithduration
新代码:// create the Animation Array for each animation
func createImageArray(total: Int, imagePrefix: String) -> [UIImage]{
var imageArray: [UIImage] = []
for imageCount in 0..<total {
let imageName = "\(imagePrefix)-\(imageCount).png"
//let image = UIImage(named: imageName)! // replaced with your code below
if let imagePath = Bundle.mainBundle.path(forResource: "ImageSet1" ofType: "png"),
let image = UIImage(contentsOfFile: imagePath) {
//Your image has been loaded }
imageArray.append(image)
}
return imageArray }