iOS视图转换动画

Question

我可能错过了一些简单的东西,但试图用图像视图做一个简单的"肯伯恩斯效应".

首先是代码:

[UIView animateWithDuration:20
                      delay:2
                    options:UIViewAnimationCurveLinear
                 animations:^{
                   CGAffineTransform move = CGAffineTransformMakeTranslation(40, 40);
                   CGAffineTransform zoom    = CGAffineTransformMakeScale(1.2, 1.2);
                   CGAffineTransform transform = CGAffineTransformConcat(zoom, move);
                   self.imageView.transform = transform;
                 }
                 completion:^(BOOL finished){
                   NSLog(@"Done");
                 }];

我希望这可以从正常比例的图像视图开始,并在20秒内将其扩展到120%的大小.实际发生的是它立即开始小于正常尺寸,然后扩展到正常尺寸.

如果我使用比例值的倒数,它会开始放大然后缩小到正常比例,这与我想要的效果相反.

有任何想法吗？

Answer 1

好吧,这实际上有效,并做我想要的.

CABasicAnimation *transformAnimation = [CABasicAnimation animationWithKeyPath:@"transform"];
transformAnimation.duration = 20.0;
transformAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
transformAnimation.removedOnCompletion = NO;
transformAnimation.fillMode = kCAFillModeForwards;

CATransform3D xform = CATransform3DIdentity;
xform = CATransform3DScale(xform, 1.2, 1.2, 1.0);
xform = CATransform3DTranslate(xform, 60, -60, 0);
transformAnimation.toValue = [NSValue valueWithCATransform3D:xform];
[self.imageView.layer addAnimation:transformAnimation forKey:@"transformAnimation"];