移动一个UIImageView

沿着点阵移动图像的最佳方法是什么？

Answer 1

我推荐的做法是将UIImage包装在UIImageView中，并使用CAKeyframeAnimation沿着通过以下三点的path对UIImageView的图层进行animation处理：

UIImage *image = [UIImage imageNamed:@"image.png"]; imageView = [[UIImageView alloc] initWithImage:image]; [mainView addSubview:imageView]; // Remember to remove the image view and release it when done with it CAKeyframeAnimation *pathAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"]; pathAnimation.duration = 1.0f; pathAnimation.calculationMode = kCAAnimationPaced; pathAnimation.fillMode = kCAFillModeForwards; pathAnimation.removedOnCompletion = NO; CGMutablePathRef pointPath = CGPathCreateMutable(); CGPathMoveToPoint(pointPath, NULL, viewOrigin.x, viewOrigin.y); CGPathAddLineToPoint(pointPath, NULL, point1.x, point1.y); CGPathAddLineToPoint(pointPath, NULL, point2.x, point2.y); CGPathAddLineToPoint(pointPath, NULL, point3.x, point3.y); pathAnimation.path = pointPath; CGPathRelease(pointPath); [imageView.layer addAnimation:pathAnimation forKey:@"pathAnimation"]; 

请注意，默认情况下，图层的位置位于图层的中心。 如果要将图层相对于另一个参考点移动，可以将图层的anchorPoint属性设置为其左上angular（iPhone上）的（0.0，0.0）或（0.0，1.0）下的剩下。

此外，这不会改变UIImageView的框架，所以如果你稍后再引用这个框架，你可能需要考虑这一点，或者在animation结束时添加一个委托方法callback来设置它到适当的价值。

通过用CGPathAddCurveToPoint（）replace对CGPathAddLineToPoint（）的调用，也可以使图像沿着曲线而不是直线移动。

编辑（5/14/2009）：我添加了缺less的pathAnimation.path = pointPath行，并改变了错误的引用curvePath到pointPath。

Answer 2

最简单的方法是使用UIViewanimation

一个快速的例子，假设你能够使用UIImageView来保存图像和NSArray来保持你的观点。

  UIImage *image = [UIImage imageNamed:@"image.png"]; UIImageView *imageView = [[UIImageView alloc] initWithImage:image]; [someView addSubview:imageView]; // Assume someView exists NSValue *firstPoint = [NSValue valueWithCGPoint:CGPointMake(0, 0)]; NSValue *secondPoint = [NSValue valueWithCGPoint:CGPointMake(100, 0)]; NSValue *thirdPoint = [NSValue valueWithCGPoint:CGPointMake(100, 100)]; // And so on.... NSArray *points = [NSArray arrayWithObjects:firstPoint, secondPoint, thirdPoint, nil]; for (NSValue *pointValue in points) { [UIView beginAnimations:@"UIImage Move" context:NULL]; CGPoint point = [pointValue CGPointValue]; CGSize size = imageView.frame.size; imageView.frame = CGRectMake(point.x, point.y, size.width, size.height); [UIView commitAnimations]; }