在扩展图像上捏合手势识别器

Question

我已将点击手势识别器操作添加到我的图像视图中。点击图像后，它会扩展到全屏，然后再次点击会关闭全屏。在图像已经展开后，我将如何添加缩放以缩放图像。这是我制作全屏图像的代码。

//expand image


let newImageView: UIImageView!

@IBAction func imageTapped(_ sender: UITapGestureRecognizer)




{
    let imageView = sender.view as! UIImageView

    let scrollView = UIScrollView(frame: self.view.frame)


    let newImageView = UIImageView(image: imageView.image)
    newImageView.frame = self.view.frame
    newImageView.backgroundColor = .black
    newImageView.contentMode = .scaleAspectFit
    newImageView.isUserInteractionEnabled = true


    let tap = UITapGestureRecognizer(target: self, action: #selector(dismissFullscreenImage))
    scrollView.addGestureRecognizer(tap)


    scrollView.delegate = self
    scrollView.minimumZoomScale = 1.0
    scrollView.maximumZoomScale = 5.0

    scrollView.addSubview(newImageView)

    self.view.addSubview(scrollView)
}

func viewForZooming(in scrollView: UIScrollView) -> UIView?
{
    return newImageView;
}

func dismissFullscreenImage(_ sender: UITapGestureRecognizer) {
    sender.view?.removeFromSuperview()
}

Answer 1

如果你想缩放imageView，你应该在UIScrollView上添加imageView并添加下面的方法：

- (CGRect)zoomRectForScrollView:(UIScrollView *)scrollView withScale:(float)scale withCenter:(CGPoint)center {

    CGRect zoomRect;

    // The zoom rect is in the content view's coordinates.
    // At a zoom scale of 1.0, it would be the size of the
    // imageScrollView's bounds.
    // As the zoom scale decreases, so more content is visible,
    // the size of the rect grows.
    zoomRect.size.height = scrollView.frame.size.height / scale;
    zoomRect.size.width  = scrollView.frame.size.width  / scale;

    // choose an origin so as to get the right center.
    zoomRect.origin.x = center.x - (zoomRect.size.width  / 2.0);
    zoomRect.origin.y = center.y - (zoomRect.size.height / 2.0);

    return zoomRect;
}

了解更多详情：https://developer.apple.com/library/content/documentation/WindowsViews/Conceptual/UIScrollView_pg/ZoomZoom/ZoomZoom.html

Answer 2

如果您想显示完整图片，请使用 scrollview 而不是 imageView

let newImageView: UIImageView!

@IBAction func imageTapped(_ sender: UITapGestureRecognizer)
{
    let imageView = sender.view as! UIImageView

    let scrollView = UIScrollView(frame: self.view.frame);

    newImageView = UIImageView(image: imageView.image)
    newImageView.frame = self.view.frame
    newImageView.backgroundColor = .black
    newImageView.contentMode = .scaleAspectFit
    newImageView.isUserInteractionEnabled = true


    let tap = UITapGestureRecognizer(target: self, action: #selector(dismissFullscreenImage))
    scrollView.addGestureRecognizer(tap)

    scrollView.delegate = self
    scrollView.minimumZoomScale = 1.0
    scrollView.maximumZoomScale = 5.0

    scrollView.addSubview(newImageView)
    self.view.addSubview(scrollView)
}

并记住 viewForZooming 委托函数

 func viewForZooming(in scrollView: UIScrollView) -> UIView?
 {
     return newImageView;
 }

在扩展图像上捏合手势识别器

pinch gesture recognizer on expanded image

uiimageview

ios

uipinchgesturerecognizer

swift