ios - UIImageView:AspecT Fit 无法与 UIScrollView 一起使用以将其缩放到全宽

Question

我有一个 UIViewController。该viewController包含UIScrollView和呈现的UIImageView。我的 UIImage 的大小小于父 View 的宽度，因此我想缩放此 UIImageView 的宽度以使其与父 View 相同。在添加 UIScrollView 之前，我对 UIImageView 使用了 .scaleAspectFit 并且它工作得很好。但现在当我使用 UIScrollView 时，它会显示实际大小的图像。

       guard let image = image, scrollView.frame.size.width > 0,  scrollView.frame.size.height > 0 else {
            return
        }
        let widthScale = scrollView.frame.size.width / image.size.width
        let heightScale = scrollView.frame.size.height / image.size.height
        scrollView.minimumZoomScale = min(min(widthScale, heightScale),1)
        scrollView.zoomScale = scrollView.minimumZoomScale
        imageView.setImage(image)
        imageView.contentMode = .scaleAspectFit
        scrollView.addSubview(imageView)    
        imageView.translatesAutoresizingMaskIntoConstraints = false
        scrollView.delegate = self
        scrollView.addSubview(imageView)
        scrollView.maximumZoomScale = 10.0

Answer 1

我改变了UIScrollView的zoomScale:

    scrollView.minimumZoomScale = min(min(widthScale, heightScale),1)
    scrollView.zoomScale = min(widthScale, heightScale)

而不是:

    scrollView.minimumZoomScale = min(min(widthScale, heightScale),1)
    scrollView.zoomScale = scrollView.minimumZoomScale

它有效。