iphone - 在 IOS 上的单个 ScrollView 中捏缩放两个 ImageView

Question

我正在做一个项目，其中我需要两个带有缩放选项的滚动视图中的图像视图。UIScrollView 允许一个视图轻松进行缩放。但我的问题不是这样的。我在滚动视图中有两个并排的图像视图。当我尝试缩放图像时它不起作用是否有任何选项可以同时缩放两个图像视图。请建议我一些想法。

提前致谢

Answer 1

这是在单个滚动视图中缩放两个图像的代码

我UIImageView在 One中添加了两个UIView，然后添加了UIViewto UIScrollView。以下是我的代码：

- (void)viewDidLoad {
    [super viewDidLoad];
    self.vwImages = [[UIView alloc]initWithFrame:CGRectMake(0, 0,100,200)];

    // 1
    UIImage *image = [UIImage imageNamed:@"imgBaskteBall2.jpeg"];
    UIImageView *imageView1 = [[UIImageView alloc] initWithImage:image];
    imageView1.frame = CGRectMake(0,0,100,100);
    [self.vwImages addSubview:imageView1];

    UIImage *image2 = [UIImage imageNamed:@"imgBaskteBall1.jpeg"];
    UIImageView *imageView2 = [[UIImageView alloc] initWithImage:image2];
    imageView2.frame = CGRectMake(0, 100, 100, 100);
    [self.vwImages  addSubview:imageView2];

    // 2

    [self.scrollView addSubview:self.vwImages];

    self.scrollView.contentSize = self.vwImages.frame.size;

    // 3
    UITapGestureRecognizer *doubleTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(scrollViewDoubleTapped:)];
    doubleTapRecognizer.numberOfTapsRequired = 2;
    doubleTapRecognizer.numberOfTouchesRequired = 1;
    [self.scrollView addGestureRecognizer:doubleTapRecognizer];

    UITapGestureRecognizer *twoFingerTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(scrollViewTwoFingerTapped:)];
    twoFingerTapRecognizer.numberOfTapsRequired = 1;
    twoFingerTapRecognizer.numberOfTouchesRequired = 2;
    [self.scrollView addGestureRecognizer:twoFingerTapRecognizer];
}


- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];

    // 4
    CGRect scrollViewFrame = self.scrollView.frame;
    CGFloat scaleWidth = scrollViewFrame.size.width / self.scrollView.contentSize.width;
    CGFloat scaleHeight = scrollViewFrame.size.height / self.scrollView.contentSize.height;
    CGFloat minScale = MIN(scaleWidth, scaleHeight);
    self.scrollView.minimumZoomScale = minScale;

    // 5
    self.scrollView.maximumZoomScale = 10.0f;
    self.scrollView.zoomScale = minScale;

    // 6
    [self centerScrollViewContents];
}


- (void)centerScrollViewContents {
    CGSize boundsSize = self.scrollView.bounds.size;
    CGRect contentsFrame = self.vwImages.frame;

    if (contentsFrame.size.width < boundsSize.width) {
        contentsFrame.origin.x = (boundsSize.width - contentsFrame.size.width) / 2.0f;
    } else {
        contentsFrame.origin.x = 0.0f;
    }

    if (contentsFrame.size.height < boundsSize.height) {
        contentsFrame.origin.y = (boundsSize.height - contentsFrame.size.height) / 2.0f;
    } else {
        contentsFrame.origin.y = 0.0f;
    }

    self.vwImages.frame = contentsFrame;
}

- (void)scrollViewDoubleTapped:(UITapGestureRecognizer*)recognizer {
    // 1
    CGPoint pointInView = [recognizer locationInView:self.imageView];

    // 2
    CGFloat newZoomScale = self.scrollView.zoomScale * 1.5f;
    newZoomScale = MIN(newZoomScale, self.scrollView.maximumZoomScale);

    // 3
    CGSize scrollViewSize = self.scrollView.bounds.size;

    CGFloat w = scrollViewSize.width / newZoomScale;
    CGFloat h = scrollViewSize.height / newZoomScale;
    CGFloat x = pointInView.x - (w / 2.0f);
    CGFloat y = pointInView.y - (h / 2.0f);

    CGRect rectToZoomTo = CGRectMake(x, y, w, h);

    // 4
    [self.scrollView zoomToRect:rectToZoomTo animated:YES];
}

- (void)scrollViewTwoFingerTapped:(UITapGestureRecognizer*)recognizer {
    // Zoom out slightly, capping at the minimum zoom scale specified by the scroll view
    CGFloat newZoomScale = self.scrollView.zoomScale / 1.5f;
    newZoomScale = MAX(newZoomScale, self.scrollView.minimumZoomScale);
    [self.scrollView setZoomScale:newZoomScale animated:YES];
}

- (UIView*)viewForZoomingInScrollView:(UIScrollView *)scrollView {
    // Return the view that you want to zoom
    return self.vwImages;
}

- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
    // The scroll view has zoomed, so you need to re-center the contents
    [self centerScrollViewContents];
}

Answer 2

将 UIView 的对象作为容器，例如 viewContainer

[viewContainer addSubView:imageView1];

[viewContainer addSubView:imageView2];

[scrollView addSubView:viewContainer];

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

添加

Answer 3

你可以用这个

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView 
{
    return [self.scrollView.subviews objectAtIndex:0];
}

委托方法返回索引 0 处的viewForZoomingInScrollView对象。

从正确缩放包含许多子视图的 UIScrollView

Answer 4

在视图中添加 imageView 并替换此方法

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