图片由小到大缓慢显示的效果

UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 0, 0)];[imageView setImage:[UIImage imageNamed:@"star.png"]];self.myImageView = imageView;[self.view addSubview:imageView];[imageView release];CGContextRef context = UIGraphicsGetCurrentContext();[UIView beginAnimations:nil context:context];[UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];[UIView setAnimationDuration:2.5];CGImageRef img = [self.myImageView.image CGImage];[myImageView setFrame:CGRectMake(0, 0, CGImageGetWidth(img), CGImageGetHeight(img))];    [UIView commitAnimations];

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