CABasicAnimation问题

Question

所以，我在文档中读到，使用像这样的块

beginAnimation
commitAnimation

从os4.0开始就不鼓励了。

因此，我尝试使用CABasicAnimation来让我的代码正常工作。我想实现的是，在我的iPhone上，图像的边框可以从缩略图大小调整到全宽位置，例如(0,120,320,240)。

到目前为止，我所拥有的：

[CATransaction begin];
[CATransaction setValue:[NSNumber numberWithFloat:1.0] forKey:kCATransactionAnimationDuration]; 

CABasicAnimation *scalingAnimation;
scalingAnimation = [CABasicAnimation animationWithKeyPath:@"transform"];
scalingAnimation.duration=1.0/2;
scalingAnimation.autoreverses=YES;
scalingAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
scalingAnimation.fromValue=[NSValue valueWithCATransform3D:CATransform3DMakeScale(1.0, 1.0, 1.0)];
scalingAnimation.toValue=[NSValue valueWithCATransform3D:CATransform3DMakeScale(4, 4, 1)];

[b.layer addAnimation:scalingAnimation forKey:@"scaling"];

[CATransaction commit];

我的下一步是首先尝试将图像移动到中心位置，然后将其缩放到正确的大小。然而，我怀疑我这样做的方式是正确的。有没有人可以评论我的代码/方法...有没有更好的方法？

Answer 1

我很确定你现在已经解决了这个问题，但不管怎样。

你不应该需要CATransaction begin；和CATransaction commit；我发现做这种事情的最简单的方法是使用CAAnimationGroup和，然后一个接一个地添加动画。

一个例子就是

CABasicAnimation *scaleX = [CABasicAnimation animationWithKeyPath:@"transform.scale.x"];
//this is not used, as the group provides the duration
scaleX.duration = duration;
scaleX.autoreverses = NO;

scaleX.toValue = [NSNumber numberWithFloat:1.0];
scaleX.fromValue = [NSNumber numberWithFloat:scaleFrom]; 
scaleX.fillMode = kCAFillModeForwards;
scaleX.removedOnCompletion = NO;

CABasicAnimation *scaleY = [CABasicAnimation animationWithKeyPath:@"transform.scale.y"];
//this is not used, as the group provides the duration
scaleY.duration = duration;
scaleY.autoreverses = NO;

scaleY.toValue = [NSNumber numberWithFloat:1.0];
scaleY.fromValue = [NSNumber numberWithFloat:scaleFrom]; 
scaleY.fillMode = kCAFillModeForwards;
scaleY.removedOnCompletion = NO;

//add in the translation animations

NSMutableArray* animationsArray = [NSMutableArray arrayWithObjects:scaleX,
                                                                   scaleY, 
//and any other animations you want in the group
                                       nil];

CAAnimationGroup *animationGroup = [CAAnimationGroup animation];
animationGroup.duration = 1.0/2;
animationGroup.timingFunction = [CAMediaTimingFunctionfunctionWithName:kCAMediaTimingFunctionEaseIn];
animationGroup.animations = animationsArray;
animationGroup.delegate = self;
animationGroup.removedOnCompletion = YES;
animationGroup.fillMode = kCAFillModeForwards;
[animationGroup setValue:@"imageTransform" forKey:@"AnimationName"];
[b.layer addAnimation:animationGroup forKey:@"imageTransform"];

不过，也有一些问题。动画是纯视觉的，因此在运行动画之前，请设置最终的图框。

你会注意到比例以1结束，这是为了确保你不会以缩放的图像层结束。相反，我们开始缩放它并将其恢复到正常状态。

翻译应该以同样的方式进行。

希望这能有所帮助

Answer 2

//in Event Method Copy Below code to place the image to the center

    CABasicAnimation* positionAnimation;
    positionAnimation = [CABasicAnimation animationWithKeyPath:@"position"];
    positionAnimation.fromValue = [NSValue valueWithCGPoint:imageView.layer.position];
    positionAnimation.toValue = [NSValue valueWithCGPoint:centerPointofView];
    positionAnimation.duration = 2.0;
    positionAnimation.fillMode = kCAFillModeForwards;
    positionAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
    positionAnimation.removedOnCompletion = NO;
    positionAnimation.delegate = self;
    [imageView.layer addAnimation:positionAnimation forKey:@"positionAnimation"];

// For Scale After image is in center copy below code

    - (void)animationDidStop:(CAAnimation *)theAnimation finished:(BOOL)flag{
    CAAnimation *animation = [imageView.layer animationForKey:@"positionAnimation"];
    if (animation == theAnimation) 
    {
        CABasicAnimation* scaleAnimation;
        scaleAnimation = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
        scaleAnimation.fromValue = [NSNumber numberWithFloat:1];
        scaleAnimation.toValue = [NSNumber numberWithFloat:4.0];
        scaleAnimation.duration = 2.2;
        scaleAnimation.fillMode = kCAFillModeForwards;
       scaleAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
        scaleAnimation.removedOnCompletion = NO;
        scaleAnimation.delegate = self;
        [imageView.layer addAnimation:scaleAnimation forKey:@"scaleAnimation"];
    }
    else 
    {
        //if you want changes to image should remain forever 
        //place your code for scale & transform here
        ....................
        //now simple remove animation from layer
        [imageView.layer removeAllAnimations];
    }
}

Answer 3

你不能用

[UIView animateWithDuration:2.0
                        animations:^{ 
                            //animations
                        } 
                        completion:^(BOOL finished){
                           // completion methods
                        }];