UIScrollView缩放

- (void)viewDidLoad{

    UIScrollView *sv2 = [[UIScrollView alloc]initWithFrame:self.view.bounds];

    sv2.delegate = self;

    sv2.minimumZoomScale = 1;

    sv2.maximumZoomScale = 10;

    float scale = self.view.frame.size.height/self.view.frame.size.width;

    NSLog(@"%f",scale);

    UIImageView *iv1 = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 2960/8, 3208/8)];

    iv1.image = [UIImage imageNamed:@"tool_subwayLine.gif"];

    [sv2 addSubview:iv1];

    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tap:)];

    tap.numberOfTapsRequired = 2;

    [sv2 addGestureRecognizer:tap];

    sv2.zoomScale=3;

    //[sv2 setContentSize:CGSizeMake(320*4, 347*4)];

    [self.view addSubview:sv2];

}

- (void)tap:(UITapGestureRecognizer *)tap {

    UIScrollView *sv = (UIScrollView *)tap.view;

    

    if (sv.zoomScale >= 4){

        sv.zoomScale = 1;

    }else sv.zoomScale=4;

}

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

    return [scrollView.subviews firstObject];

}