UIScrollView 与 UIImageView。图像未向上滚动

Posted 2023-02-25

【中文标题】UIScrollView 与 UIImageView。图像未向上滚动

【英文标题】：UIScrollView with UIImageView. Image is not scrolled up

【发布时间】：2014-07-10 19:13:55

【问题描述】：

这是UIScrollView、UIImageView 的代码。 When the next image is chosen the resetStatusImage is called. statusMessageImageView 作为放大 UIScrollView 委托的视图返回。 当使用最小缩放时，图像无法向上滚动，但仍有图像部分需要滚动。至于底部、左侧和右侧，它们是完全可见的，不能分别向下、向左和向右滚动。为什么最小缩放时图像不能向上滚动？

- (void)viewDidLoad

    CGRect r = CGRectMake(0, 0, self.statusMessageTextView.bounds.size.width, 455);
    statusMessageImageView = [[UIImageView alloc] initWithFrame:r];
    statusMessageImageView.contentMode = UIViewContentModeCenter;

    // Set up the scroll view for the image zooming in/out and scrolling.
    imgScrollView = [[UIScrollView alloc] initWithFrame:statusMessageImageView.bounds];
    [imgScrollView setScrollEnabled:YES];
    [imgScrollView setClipsToBounds:YES];

    [self.view addSubview:imgScrollView];

    [imgScrollView setBackgroundColor:[UIColor yellowColor]];

    [imgScrollView setContentSize:statusMessageImageView.frame.size]; // this is your image view size
    imgScrollView.delegate = self;

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

    [imgScrollView addSubview:statusMessageImageView];
    [imgScrollView addSubview:self.statusMessageTextView];

- (void)resetStatusImage

    imgScrollView.zoomScale = 1.0;

    UIImage *statusImage = self.statusImageManager.currentStatusImage;
    NSLog(@"Image size %f %f", statusImage.size.width, statusImage.size.height);

    // Set the image view fram size equal to the image size.
    statusMessageImageView.frame = (CGRect).origin=CGPointMake(0.0f, 0.0f), .size=statusImage.size;
    [statusMessageImageView setImage:statusImage];

    // Set the scroll view content size and zoom scale.
    imgScrollView.contentSize = statusImage.size;
    CGFloat scaleWidth = imgScrollView.frame.size.width / imgScrollView.contentSize.width;
    CGFloat scaleHeight = imgScrollView.frame.size.height / imgScrollView.contentSize.height;
    CGFloat maxScale = MAX(scaleWidth, scaleHeight);
    imgScrollView.minimumZoomScale = maxScale;
    imgScrollView.maximumZoomScale = 1.0f;
    imgScrollView.zoomScale = maxScale;

    // Save current scroll view content data
    // to detect that the user changed the visible area.
    contentOffsetX = imgScrollView.contentOffset.x;
    contentOffsetY = imgScrollView.contentOffset.y;
    zoomScale = imgScrollView.zoomScale;

【参考方案1】：

-(UIView *) viewForZoomingInScrollView:(UIScrollView *)inScroll 
 return imageView;
 

这会对你有所帮助。

【讨论】：

但这对他有什么帮助？你能补充更多信息吗？

【参考方案2】：

statusMessageTextView 高度值是错误的。禁用自动缩放也会影响statusMessageTextView 在缩放时的位置，移动图像：文本视图也会移动。