Question

我有UIImageView的图片。现在我有一个全新的图像（图形文件），并希望在此UIImageView中显示它。如果我只是设置

myImageView.image = newImage;

新图像立即可见。不可动画。

我希望它能够很好地淡入新图像。我想也许有更好的解决方案，而不仅仅是创建一个新的UIImageView并与动画混合？

Answer 1

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

是另一种可能性

Answer 2

我不确定你是否可以使用淡入淡出效果为UIViews设置动画，因为似乎所有支持的视图过渡都在UIViewAnimationTransition枚举中定义。使用CoreAnimation可以实现褪色效果。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 3

用迈克尔斯科特的话说，保持简单愚蠢。这是在 Swift 3 和 Swift 4 中执行此操作的简单方法：

UIView.transition(with: imageView,
                  duration: 0.75,
                  options: .transitionCrossDissolve,
                  animations: { self.imageView.image = toImage },
                  completion: nil)

Answer 4

<强>代码：

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;

示例：

有趣，更详细的解决方案 :( 点击水龙头）

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 5

试试这个：

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

Answer 6

Swift 5 扩展名：

extension UIImageView{
    func setImage(_ image: UIImage?, animated: Bool = true) {
        let duration = animated ? 0.3 : 0.0
        UIView.transition(with: self, duration: duration, options: .transitionCrossDissolve, animations: {
            self.image = image
        }, completion: nil)
    }
}

Answer 7

使用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)
        }
    }
}

<强>用法：

myImageView.imageWithFade = myImage

Answer 8

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 9

为什么不尝试这个。

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];

快速版本：

let animationsFrames = [UIImage(named: "image1.png"), UIImage(named: "image2.png")]
let animatedImageView = UIImageView()
animatedImageView.animationImages = animationsFrames
animatedImageView.animationRepeatCount = 1
animatedImageView.startAnimating()

Answer 10

这里有一些不同的方法：UIAnimations 对我来说，这听起来像是你的挑战。

编辑：我太懒了:)）

在帖子中，我指的是这种方法：

[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];

但不是动画帧，而是动画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 11

从iOS 5开始，这个更容易：

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

Answer 12

弗拉基米尔的答案很完美，但是像我这样寻求快速解决方案的人

此解决方案适用于 swift 4.2版

Console.WriteLine(0xffffffff >> 32);

您可以在任何地方调用此方法。它将使用动画将图像更改为下一个图像。

对于 Swift版本4.0 使用以下解决方案

var i = 0
    func animation(){
        let name = (i % 2 == 0) ? "1.png" : "2.png"
        myImageView.image = UIImage.init(named: name)
        let transition: CATransition = CATransition.init()
        transition.duration = 1.0
        transition.timingFunction = CAMediaTimingFunction.init(name: .easeInEaseOut)
        transition.type = .fade
        myImageView.layer.add(transition, forKey: nil)
        i += 1
    }

Answer 13

Swift 4 这真棒

  self.imgViewPreview.transform = CGAffineTransform(scaleX: 0, y: 0)
          UIView.animate(withDuration: 1, delay: 0, usingSpringWithDamping: 0.3, initialSpringVelocity: 0, options: .curveEaseOut, animations: {
              self.imgViewPreview.image = newImage
              self.imgViewPreview.transform = .identity
          }, completion: nil)

Answer 14

斯威夫特 5：

处理 collectionView 时。仅重新加载 1 个或多个带有动画的项目。我在更改单元格图像时尝试了一些不同的动画选项，没有区别，所以我在这里不指明动画名称。

UIView.animate(withDuration: 1.0) { [weak self] in
                guard let self = self else { return print("gotchya!") }
                self.collectionView.reloadItems(at: [indexPath])
            }

如何动画UIImageView中的图像变化？

14 个答案: