如何在UIImageView中animation变化的图像？

我有一个图像的UIImageView。 现在我有一个全新的图像（graphics文件），并希望显示在这个UIImageView。 如果我刚刚设置

myImageView.image = newImage; 

新的图像立即可见。 不能animation。

我希望它很好地淡入新的形象。 我想也许有一个更好的解决scheme，而不仅仅是创build一个新的UIImageView和混合animation？

Answer 1

我不确定是否可以使用淡入淡出效果对UIViews进行animation处理，因为看来所有支持的视图过渡都是在UIViewAnimationTransition枚举中定义的。 使用CoreAnimation可以实现衰落效果。 此方法的示例示例：

 #import <QuartzCore/QuartzCore.h> ... imageView.image = [UIImage imageNamed:(i % 2) ? @"3.jpg" : @"4.jpg"]; CATransition *transition = [CATransition animation]; transition.duration = 1.0f; transition.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]; transition.type = kCATransitionFade; [imageView.layer addAnimation:transition forKey:nil]; 

Answer 2

 [UIView transitionWithView:textFieldimageView duration:0.2f options:UIViewAnimationOptionTransitionCrossDissolve animations:^{ imageView.image = newImage; } completion:nil]; 

是另一种可能性

Answer 3

这里是Swift 3中的正确答案：

 UIView.transition(with: imageView, duration: 1, options: .transitionCrossDissolve, animations: { self.imageView.image = toImage }, completion: nil) 

Answer 4

这里是Swift中的一个例子，它将首先交叉解散一个新的图像，然后添加一个弹性animation：

 var selected: Bool { willSet(selected) { let expandTransform:CGAffineTransform = CGAffineTransformMakeScale(1.15, 1.15); if (!self.selected && selected) { UIView.transitionWithView(self.imageView, duration:0.1, options: UIViewAnimationOptions.TransitionCrossDissolve, animations: { self.imageView.image = SNStockCellSelectionAccessoryViewImage(selected) self.imageView.transform = expandTransform }, completion: {(finished: Bool) in UIView.animateWithDuration(0.4, delay:0.0, usingSpringWithDamping:0.40, initialSpringVelocity:0.2, options:UIViewAnimationOptions.CurveEaseOut, animations: { self.imageView.transform = CGAffineTransformInvert(expandTransform) }, completion:nil) }) } } } var imageView:UIImageView 

如果imageView作为子视图正确添加到视图，则在selected = false到selected = true之间切换应该用有弹性的animation交换图像。 SNStockCellSelectionAccessoryViewImage只是基于当前的select状态返回一个不同的图像，如下所示：

 private let SNStockCellSelectionAccessoryViewPlusIconSelected:UIImage = UIImage(named:"PlusIconSelected")! private let SNStockCellSelectionAccessoryViewPlusIcon:UIImage = UIImage(named:"PlusIcon")! private func SNStockCellSelectionAccessoryViewImage(selected:Bool) -> UIImage { return selected ? SNStockCellSelectionAccessoryViewPlusIconSelected : SNStockCellSelectionAccessoryViewPlusIcon } 

下面的GIF例子有点慢了，实际的animation发生得更快：

Answer 5

码：

 var fadeAnim:CABasicAnimation = CABasicAnimation(keyPath: "contents"); fadeAnim.fromValue = firstImage; fadeAnim.toValue = secondImage; fadeAnim.duration = 0.8; //smoothest value imageView.layer.addAnimation(fadeAnim, forKey: "contents"); imageView.image = secondImage; 

例：

有趣的，更详细的解决scheme 🙁 切换水龙头 ）

  let fadeAnim:CABasicAnimation = CABasicAnimation(keyPath: "contents"); switch imageView.image { case firstImage?: fadeAnim.fromValue = firstImage; fadeAnim.toValue = secondImage; imageView.image = secondImage; default: fadeAnim.fromValue = secondImage; fadeAnim.toValue = firstImage; imageView.image = firstImage; } fadeAnim.duration = 0.8; imageView.layer.addAnimation(fadeAnim, forKey: "contents"); 

Answer 6

尝试这个：

 _imageView.image = image; [_imageView.layer addAnimation:[CATransition animation] forKey:kCATransition]; 

Answer 7

 CABasicAnimation* fadeAnim = [CABasicAnimation animationWithKeyPath:@"contents"]; fadeAnim.fromValue = (__bridge id)imageView.image.CGImage; fadeAnim.toValue = (__bridge id)[UIImage imageNamed:@"newImage.png"].CGImage; fadeAnim.duration = 2.0; [imageView.layer addAnimation:fadeAnim forKey:@"contents"]; imageView.layer.contents = (__bridge id)[UIImage imageNamed:@"newImage.png"].CGImage; 

Answer 8

为什么不试试这个。

 NSArray *animationFrames = [NSArray arrayWithObjects: [UIImage imageWithName:@"image1.png"], [UIImage imageWithName:@"image2.png"], nil]; UIImageView *animatedImageView = [[UIImageView alloc] init]; animatedImageView.animationImages = animationsFrame; [animatedImageView setAnimationRepeatCount:1]; [animatedImageView startAnimating]; 

Answer 9

这里有几个不同的方法： UIAnimations我的回忆这听起来像你的挑战。

编辑：我太懒了:)

在这篇文章中，我指的是这个方法：

 [newView setFrame:CGRectMake( 0.0f, 480.0f, 320.0f, 480.0f)]; //notice this is OFF screen! [UIView beginAnimations:@"animateTableView" context:nil]; [UIView setAnimationDuration:0.4]; [newView setFrame:CGRectMake( 0.0f, 0.0f, 320.0f, 480.0f)]; //notice this is ON screen! [UIView commitAnimations]; 

但不是animation框架，你animation的alpha：

 [newView setAlpha:0.0]; // set it to zero so it is all gone. [UIView beginAnimations:@"animateTableView" context:nil]; [UIView setAnimationDuration:0.4]; [newView setAlpha:0.5]; //this will change the newView alpha from its previous zero value to 0.5f [UIView commitAnimations]; 

Answer 10

从iOS 5开始，这个更容易：

 [newView setAlpha:0.0]; [UIView animateWithDuration:0.4 animations:^{ [newView setAlpha:0.5]; }]; 

Answer 11

随着Swift 3

 extension UIImageView{ var imageWithFade:UIImage?{ get{ return self.image } set{ UIView.transition(with: self, duration: 0.5, options: .transitionCrossDissolve, animations: { self.image = newValue }, completion: nil) } } } 

用法：

 myImageView.imageWithFade = myImage