Moving an object randomly around the screen
I'm trying to animate a UIButton to move randomly around the screen in different directions. The code below is kind of working. The button will begin moving along a random path, however, it then just continues to move back and forth between point A and point B.
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:1];
[UIView setAnimationRepeatCount:1000];
[UIView setAnimationRepeatAutoreverses:YES];
CGFloat x = (CGFloat) (arc4random() % (int) self.view.bounds.size.width);
CGFloat y = (CGFloat) (arc4random() % (int) self.view.bounds.size.height);
CGPoint squarePostion = CGPointMake(x, y);
button.center = squarePostion;
[UIView commitAnimations];
How can I get it to keep开发者_运维百科 moving to a new random point every time it changes directions, instead of simply moving back and forth?
Thanks!
try this:
-(void)animationLoop:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context {
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:1];
// remove:
// [UIView setAnimationRepeatCount:1000];
// [UIView setAnimationRepeatAutoreverses:YES];
CGFloat x = (CGFloat) (arc4random() % (int) self.view.bounds.size.width);
CGFloat y = (CGFloat) (arc4random() % (int) self.view.bounds.size.height);
CGPoint squarePostion = CGPointMake(x, y);
button.center = squarePostion;
// add:
[UIView setAnimationDelegate:self]; // as suggested by @Carl Veazey in a comment
[UIView setAnimationDidStopSelector:@selector(animationLoop:finished:context:)];
[UIView commitAnimations];
}
and just add a counter (int) inside the method to check if it's executed more than 1000 times, if wanna stop it...
Swift 5 example of making one animation
@objc func didBecomeActive() {
DispatchQueue.main.async {
self.startAnimationCalm()
}
}
func startAnimation() {
let animatedShadow = UIView(frame: CGRect(origin: CGPoint(x: 10, y: 10), size: CGSize(width: 20, height: 20)))
animatedShadow.clipsToBounds = true
animatedShadow.layer.cornerRadius = 20/2
animatedShadow.backgroundColor = UIColor.green
animatedShadow.layer.borderWidth = 0
self.view.addSubview(animatedShadow)
UIView.animate(withDuration: 5, delay: TimeInterval(0), options: [.repeat, .curveEaseIn], animations: { () -> Void in
let randomX = CGFloat.random(in: 14 ... 200)
let randomY = CGFloat.random(in: 20 ... 600)
animatedShadow.center = CGPoint(x: animatedShadow.frame.origin.x + randomX, y: animatedShadow.frame.origin.y + randomY)
self.view.layoutIfNeeded()
}, completion: { finished in
})
}
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