UIScrollView缩放image

- (void)viewDidLoad {

    [superviewDidLoad];

    UIScrollView *scrollView = [[UIScrollView alloc] init];

    scrollView.frame = CGRectMake(0.0, 0.0, [UIScreenmainScreen].bounds.size.width, [UIScreenmainScreen].bounds.size.height);

    //scrollView.contentSize = CGSizeMake(scrollView.frame.size.width, scrollView.frame.size.height);

    scrollView.backgroundColor = [UIColor greenColor];

    [self.view addSubview:scrollView];

    UIImage *image = [UIImage imageNamed:@"meizi.jpg"];

    scrollView.contentSize = image.size;

    UIImageView *imageView = [[UIImageView alloc] initWithImage:image];

    imageView.tag = 200;

    [scrollView addSubview:imageView];

    scrollView.delegate = self;

    scrollView.minimumZoomScale = 0.5;

    scrollView.maximumZoomScale = 2.0;

}

// 返回这个imageview就可以对它操作

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView

{

    return (UIImageView *)[scrollView viewWithTag:200];

}