viewForZoomingInScrollView UIScrollView 背景和图像不同步

Question

我正在放大滚动视图中的图像。但我的滚动视图有一个背景，我想与前景图像保持同步。

这是我目前所拥有的。我想知道我是否也必须在 viewForZoomingInScrollView 方法中返回 bgImage 。但我只是不确定如何或是否可以激活。

这是我在下面所做的以使图像缩放..如果有人可以帮助我弄清楚如何让 bg 同步滚动也将不胜感激。

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    scrollView = [[UIScrollView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];
    scrollView.backgroundColor = [UIColor blackColor];
    scrollView.delegate = self;
    scrollView.bounces = NO;
    scrollView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"auckland-300.jpg"]];
    image = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"249a-134206f1d00-1342071f5d9.ImgPlayerAUCKLAND.png"]];
    scrollView.contentSize = image.frame.size;
    [scrollView addSubview:image];
    scrollView.minimumZoomScale = 1.0;
    scrollView.maximumZoomScale = 31.0;
    [scrollView setZoomScale:scrollView.minimumZoomScale];
    self.view = scrollView;    
}

#pragma Zooming

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
    return image;
}

Answer 1

我假设您的意思是您希望背景图像也可以缩放？我要做的是将UIImageView 也用于背景图像，并将该图像以及您的image 放入容器视图中，然后在viewForZoomingInScrollView: 中返回。所以沿着这些思路：

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    scrollView = [[UIScrollView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];
    scrollView.backgroundColor = [UIColor blackColor];
    scrollView.delegate = self;
    scrollView.bounces = NO;

    backgroundImage = [[UIImageVIew alloc] initWithImage:[UIImage imageNamed:@"auckland-300.jpg"]];

    image = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"249a-134206f1d00-1342071f5d9.ImgPlayerAUCKLAND.png"]];

    // Note here you should size the container view appropriately and layout backgroundImage and image accordingly.
    containerView = [[UIView alloc] initWithFrame:image.bounds];
    [containerView addSubview:backgroundImage];
    [containerView addSubview:image];

    scrollView.contentSize = containerView.frame.size;
    [scrollView addSubview:containerView];

    scrollView.minimumZoomScale = 1.0;
    scrollView.maximumZoomScale = 31.0;
    [scrollView setZoomScale:scrollView.minimumZoomScale];
    self.view = scrollView;    
}

#pragma Zooming

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
    return containerView;
}