在方面适合后从 UIImageView 获取图像的宽度和高度答案

【问题标题】：Getting width and height of image from UIImageView after aspect fit在方面适合后从 UIImageView 获取图像的宽度和高度
【发布时间】：2018-11-25 09:25:14
【问题描述】：

我试图从 UIImageView 中获取图像的宽度和高度，之后它被缩放到适合宽高比。这就是我得到它的宽度和高度的方式：

let imageHeight = AVMakeRect(aspectRatio: (transferImage.size), insideRect: imageView.frame).height
let imageWidth = AVMakeRect(aspectRatio: (transferImage.size), insideRect: imageView.frame).width

let imageYposition = AVMakeRect(aspectRatio: (transferImage.size), insideRect: imageView.frame).origin.y
let imageXposition = AVMakeRect(aspectRatio: (transferImage.size), insideRect: imageView.frame).origin.x

显然，这给了我宽度和高度。但是，在尝试将 UIView 调整为相同尺寸后，它们的尺寸不同。这就是我如何将 UIView 设置为图像的宽度和高度：

boundariesRectangle.frame = CGRect(x: imageXposition, y: imageYposition, width: imageWidth, height: imageHeight)

会发生这样的事情：

【问题讨论】：

您可以在情节提要中手动设置。这样更容易

标签： swift

【解决方案1】：

试试这个：

guard let image = imageView.image else { return }

// Calculate the scaled size of the image
let scaledRect = AVMakeRect(aspectRatio: image.size, insideRect: imageView.bounds)

// Create the overlay view
let overlayView = UIView(frame: .zero)
overlayView.backgroundColor = UIColor.red.withAlphaComponent(0.5)
overlayView.translatesAutoresizingMaskIntoConstraints = false

// Add the overlay
// To use relate 2 views by auto-layout constraints, they must have the
// same parent view
imageView.superView!.addSubview(overlayView)
overlayView.widthAnchor.constraint(equalToConstant: scaledRect.width).isActive = true
overlayView.heightAnchor.constraint(equalToConstant: scaledRect.height).isActive = true
overlayView.centerXAnchor.constraint(equalTo: imageView.centerXAnchor).isActive = true
overlayView.centerYAnchor.constraint(equalTo: imageView.centerYAnchor).isActive = true

【讨论】：