Question

我正在努力在动画结束时从视图中删除一个对象（blueArrow）。通过使用延迟后跟一个方法将其从superView中删除它来删除它对我来说不起作用，因为我希望在屏幕上设置这些箭头的动画流。目的是调用多次添加箭头并为箭头添加动画的方法，每次动画只发生一次，并从视图中删除它创建的箭头。我已经设置了animationDidStop方法，但似乎永远不会被调用，思想？提前谢谢！

-(void)blueArrowAnimation{

    UIImage *blueArrowImage = [UIImage imageNamed:@"blueArrow.png"];

    //Prepare the animation - we use keyframe animation for animations of this complexity
    CAKeyframeAnimation *pathAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"];
    pathAnimation.rotationMode = kCAAnimationRotateAuto;
    //Set some variables on the animation
    pathAnimation.calculationMode = kCAAnimationPaced;
    //We want the animation to persist - not so important in this case - but kept for clarity
    //If we animated something from left to right - and we wanted it to stay in the new position,
    //then we would need these parameters
    pathAnimation.fillMode = kCAFillModeForwards;
    pathAnimation.removedOnCompletion = YES;
    pathAnimation.duration = 3.0;
    //Lets loop continuously for the demonstration
    pathAnimation.repeatCount = 1;

    //Setup the path for the animation - this is very similar as the code the draw the line
    //instead of drawing to the graphics context, instead we draw lines on a CGPathRef
    CGMutablePathRef curvedPath = CGPathCreateMutable();
    CGPathMoveToPoint(curvedPath, NULL, 10, 40);
    CGPathAddQuadCurveToPoint(curvedPath, NULL, 10, 300, 130, 300);
    //CGPathAddQuadCurveToPoint(curvedPath, NULL, 310, 10, 10, 10);

    //Now we have the path, we tell the animation we want to use this path - then we release the path
    pathAnimation.path = curvedPath;
    CGPathRelease(curvedPath);

    self.blueArrow = [[UIImageView alloc] initWithImage:blueArrowImage];
    self.blueArrow .frame = CGRectMake(1, 1, 20, 20);

    pathAnimation.delegate = self;

    [self.view addSubview:self.blueArrow];
    [self.blueArrow.layer addAnimation:pathAnimation forKey:@"moveTheArrow"];

}

- (void)animationDidStop:(CAAnimation *)pathAnimation finished:(BOOL)flag
{
    CALayer *layer = [pathAnimation valueForKey:@"moveTheArrow"];
    if (layer) {
        NSLog(@"removed %@ (%@) from superview", layer, [layer name]);
        [layer removeFromSuperlayer];
    }
}

Answer 1

我创建了一个这样的类：

class ViewController: UIViewController, CAAnimationDelegate {
func creatAnimation() {
...some code
animation.delegate = self
}

func animationDidStop(_ anim: CAAnimation, finished flag: Bool) {
        print("done")
        
 }
}

animationDidStop 在动画结束时启动。

但是我在完成动画后删除图像时遇到问题。所以最后，这对我有用： let projectile = UIImageView(image: UIImage(named: assetName)) projectile.frame = CGRect(x:boardFields[indexField].fieldImage.frame.minX, y:boardFields[indexField].fieldImage.frame.minY,width:width,height:height) projectile.transform = projectile.transform.rotated(by: -angle) self.view.addSubview(projectile)

    UIView.animate(withDuration: 2, animations: {
        let animation = CAKeyframeAnimation()
        animation.keyPath = "position.x" // move along x axis
        animation.values = [0, xTranslation]
        animation.keyTimes = [0, 1]
        animation.duration = duration
        animation.isAdditive = true
        projectile.layer.add(animation, forKey: "moveX")
        
        animation.keyPath = "position.y" // move along y axis
        animation.values = [0, yTranslation]
        animation.keyTimes = [0, 1]
        animation.duration = duration
        animation.isAdditive = true
        projectile.layer.add(animation, forKey: "moveY")
        
        animation.keyPath = "bounds.size.width" // grow and than shrink width of image
        animation.values = [0, 200, 0]
        animation.keyTimes = [0, 0.5, 1]
        animation.duration = duration
        animation.isAdditive = true
        projectile.layer.anchorPoint = CGPoint(x: 0.5, y: 0.5)
        projectile.layer.add(animation, forKey: "resize.width")
        
        animation.keyPath = "bounds.size.height" // grow and than shrink width of image
        animation.values = [0, 100, 0]
        animation.keyTimes = [0, 0.5, 1]
        animation.duration = duration
        animation.isAdditive = true
        animation.isRemovedOnCompletion = true
        animation.delegate = self
        projectile.layer.anchorPoint = CGPoint(x: 0.5, y: 0.5)
        projectile.layer.add(animation, forKey: "resize.width")
    }, completion: { finished in
        projectile.removeFromSuperview()
    })

动画完成后删除对象

1 个答案: