I am trying to find the current position of an iPhone ImageView that is animating across the screen.
I create and animate the imageView like so
-(IBAction)button:(UIButton *)sender{
UIImageView *myImageView =[[UIImageView alloc] initWithImage:
开发者_运维百科 [UIImage imageNamed:@"ball.png"]];
myImageView.frame = CGRectMake(0, self.view.frame.size.height/2, 40, 40);
[self.view addSubview:myImageView];
[myArray addObject:myImageView];
[UIView animateWithDuration:.5
delay:0
options:(UIViewAnimationOptionAllowUserInteraction) // | something here?)
animations:^{
myImageView.frame = CGRectOffset(myImageView.frame, 500, 0);
}
completion:^(BOOL finished){
[myArray removeObject:myImageView];
[myImageView removeFromSuperview];
[myImageView release];
}
];
}
then to detect the current CGPoint of the imageView I call this method every 60th of a second
-(void)findPoint{
for (UIImageView *projectile in bullets) {
label.text = [NSString stringWithFormat:@"%f", projectile.center.x];
label2.text = [NSString stringWithFormat:@"%f", projectile.center.y];
}
}
However this only gives me the point where the animation ends, I want to get the current CGPoint of the image that is animating across the screen. Is there an option that I need to apply other than UIViewAnimationOptionAllowUserInteraction to do this? If not, how do I get the current position of an animating imageView?
You can use the presentationLayer - a property of the CALayer that "provides a close approximation to the version of the layer that is currently being displayed". Just use it like this:
CGRect projectileFrame = [[projectile.layer presentationLayer] frame];
Swift 5: Get temporary position and size (CGRect) during the animation with:
let currentFrame = projectileFrame.layer.presentation()!.frame
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