UIScrollView中实现图片的放大缩小

UIScrollView中实现图片的放大缩小

img=[[UIImageView alloc]initWithImage:[UIImage imageNamed:@"aa.png"]];    scrollView=[[UIScrollView alloc]initWithFrame:CGRectMake(60, 60, 200, 200)];    [scrollView setBackgroundColor:[UIColor grayColor]];    scrollView.contentSize=CGSizeMake(img.image.size.width, img.image.size.height);    scrollView.minimumZoomScale=0.1;    scrollView.maximumZoomScale=2.0;        scrollView.showsHorizontalScrollIndicator=YES;    scrollView.showsVerticalScrollIndicator=YES;    scrollView.bounces=NO; //反弹效果    scrollView.alwaysBounceVertical=YES;    scrollView.alwaysBounceHorizontal=YES;    scrollView.delegate=self;    [self.view addSubview:scrollView];    [self.scrollView addSubview:img];

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView{    return img;//UIImageView对象}