在iOS中使用筛选器进行CATransition

Question

I'm trying to set a filter to CATransition. What seems to be so simple turned out problematic - it seems that the filter property is being ignored by CATransition and I'm left with the default fade effect (?!)

UIImage *start = [UIImage imageNamed:@"start"];
UIImage *target = [UIImage imageNamed:@"target"];

CIImage *startImg = [CIImage imageWithCGImage:start.CGImage];
CIImage *endImg = [CIImage imageWithCGImage:target.CGImage];

CIFilter *filter = [CIFilter filterWithName:@"CICopyMachineTransition" keysAndValues:
                    @"inputImage" , startImg,
                    @"inputTargetImage" , endImg,
                    @"inputTime" , @1.0, nil];

CATransition *transition = [CATransition new];

transition.duration = 1.75;
transition.filter = filter;

[self.imageView.layer addAnimation:transition forKey:kCATransition];

self.imageView.image = target;

Answer 1

I ran into something similar and this post helped me out:

Using transition CIFilters for CATransition

Basically, I was trying to use a filter combination that was unavailable on the IOS version I was running, but it took reading through that post to get me into the docs to figure it all out.

Hope that gets you headed in the right direction.

UPDATE:

Looking at this again, I wonder if your problem is here:

CATransition *transition = [CATransition new];

Shouldn't you be calling the animation selector instead?

CATransition *transition = [CATransition animation];

I'm not sure what 'new' does in this case or if it would initialize properly.