coreAnimation    // 1.初始化演员    CALayer *layer = [[CALayer alloc]init];    layer.bounds = CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height);    layer.position = CGPointMake(160, 160);    // 设置内容    //layer.contents = (id)_imageViewBtn.imageView.image.CGImage    [self.view.layer addSublayer:layer];        // 2.设定剧情    // 贝尔曲线    UIBezierPath *movePath = [UIBezierPath bezierPath];    [movePath moveToPoint:layer.position];    [movePath addQuadCurveToPoint:CGPointMake(319, [UIScreen mainScreen].bounds.size.height - 45 - 20)                     controlPoint:CGPointMake(0,0)];        // 关键帧    CAKeyframeAnimation *positionnAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"];    positionnAnimation.path = movePath.CGPath;    positionnAnimation.removedOnCompletion = YES;        // 基本动画(缩放)    CABasicAnimation *scaleAnimation = [CABasicAnimation animationWithKeyPath:@"transform.sale"];    scaleAnimation.fromValue = @1;    scaleAnimation.toValue = @.025;    scaleAnimation.duration = .8f;    scaleAnimation.autoreverses = NO;    scaleAnimation.repeatCount = 1;    // 防止动画闪烁    scaleAnimation.removedOnCompletion = NO;    scaleAnimation.fillMode = kCAFillModeForwards;        scaleAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];        // 组动画    CAAnimationGroup *animationGroup = [CAAnimationGroup animation];    animationGroup.duration = 0.8f;    animationGroup.autoreverses = NO;    animationGroup.repeatCount = 1;    animationGroup.repeatDuration = NO;    animationGroup.fillMode = kCAFillModeForwards;    [animationGroup setAnimations:[NSArray arrayWithObjects:positionnAnimation,scaleAnimation, nil]];        // 3.播放    [layer addAnimation:animationGroup forKey:nil];