如何驱动图像沿曲线运动？

UIImageView *imageViewForAnimation = [[UIImageView alloc] initWithImage:imageToAnimate]; imageViewForAnimation.alpha = 1.0f; CGRect imageFrame = imageViewForAnimation.frame; //frame.origin，动画开始的地方 CGPoint viewOrigin = imageViewForAnimation.frame.origin; viewOrigin.y = viewOrigin.y + imageFrame.size.height / 2.0f; viewOrigin.x = viewOrigin.x + imageFrame.size.width / 2.0f;

imageViewForAnimation.frame = imageFrame; imageViewForAnimation.layer.position = viewOrigin; [self.view addSubview:imageViewForAnimation];

// 淡出效果 CABasicAnimation *fadeOutAnimation = [CABasicAnimation animationWithKeyPath:@"opacity"]; [fadeOutAnimation setToValue:[NSNumber numberWithFloat:0.3]]; fadeOutAnimation.fillMode = kCAFillModeForwards; fadeOutAnimation.removedOnCompletion = NO;

//设置缩放 CABasicAnimation *resizeAnimation = [CABasicAnimation animationWithKeyPath:@"bounds.size"]; [resizeAnimation setToValue:[NSValue valueWithCGSize:CGSizeMake(40.0f, imageFrame.size.height * (40.0f / imageFrame.size.width))]]; resizeAnimation.fillMode = kCAFillModeForwards; resizeAnimation.removedOnCompletion = NO;

// 设置路径运动 CAKeyframeAnimation *pathAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"]; pathAnimation.calculationMode = kCAAnimationPaced; pathAnimation.fillMode = kCAFillModeForwards; pathAnimation.removedOnCompletion = NO; //设置动画结束点 CGPoint endPoint = CGPointMake(480.0f - 30.0f, 40.0f); //在最后一个选项卡结束动画 //CGPoint endPoint = CGPointMake( 320-40.0f, 480.0f); CGMutablePathRef curvedPath = CGPathCreateMutable(); CGPathMoveToPoint(curvedPath, NULL, viewOrigin.x, viewOrigin.y); CGPathAddCurveToPoint(curvedPath, NULL, endPoint.x, viewOrigin.y, endPoint.x, viewOrigin.y, endPoint.x, endPoint.y); pathAnimation.path = curvedPath; CGPathRelease(curvedPath);

CAAnimationGroup *group = [CAAnimationGroup animation]; group.fillMode = kCAFillModeForwards; group.removedOnCompletion = NO; [group setAnimations:[NSArray arrayWithObjects:fadeOutAnimation, pathAnimation, resizeAnimation, nil]]; group.duration = 0.7f; group.delegate = self; [group setValue:imageViewForAnimation forKey:@"imageViewBeingAnimated"];

[imageViewForAnimation.layer addAnimation:group forKey:@"savingAnimation"];

[imageViewForAnimation release];