在 1 个函数中截取 2 个不同尺寸图像的屏幕截图

Question

我希望下面的 swift 代码截取 2 个屏幕截图。一个屏幕截图应该是从顶部到 20% 的整个视图，另一个是从 20% 到 100% 的高度。我创建了一个图像来显示我正在寻找的东西。图片应该有不同的比例。我真的不知道还有什么要补充的。

var drawbox = Canvas()
 @objc func image(_ image: UIImage, didFinishSavingWithError error: Error?, contextInfo: UnsafeRawPointer) {
    if let error = error {
        // we got back an error!
        let ac = UIAlertController(title: "Save error", message: error.localizedDescription, preferredStyle: .alert)
        ac.addAction(UIAlertAction(title: "OK", style: .default))
        present(ac, animated: true)
    } else {
        let ac = UIAlertController(title: "Saved!", message: "Your altered image has been saved to your photos.", preferredStyle: .alert)
        ac.addAction(UIAlertAction(title: "OK", style: .default))
        present(ac, animated: true)
    }
}
 @objc func saving(){
     
            
            let vex = self.view.screenshot(for: drawbox.frame, clipToBounds: true)
            
            
            UIImageWriteToSavedPhotosAlbum(vex, self, #selector(image(_:didFinishSavingWithError:contextInfo:)), nil)
        }
    
extension UIView {
    /// Takes a screenshot of a UIView, with an option to clip to view bounds and place a waterwark image
    /// - Parameter rect: offset and size of the screenshot to take
    /// - Parameter clipToBounds: Bool to check where self.bounds and rect intersect and adjust size so there is no empty space
    /// - Parameter watermark: UIImage of the watermark to place on top
    func screenshot(for rect: CGRect, clipToBounds: Bool = true, with watermark: UIImage? = nil) -> UIImage {
        var imageRect = rect
        if clipToBounds {
            imageRect = bounds.intersection(rect)
        }
        return UIGraphicsImageRenderer(bounds: imageRect).image { _ in
            drawHierarchy(in: CGRect(origin: .zero, size: bounds.size), afterScreenUpdates: true)
            watermark?.draw(in: CGRect(origin: imageRect.origin, size: CGSize(width: 32, height: 32))) // update origin to place watermark where you want, with this update it will place it in top left or screenshot.
        }
    }
}

Answer 1

图片保存后可以分割我用这个功能把图片分割成两半你可以改变比例

     extension UIImage {
     
    func topHalf(pers:CGFloat)-> UIImage? {
        guard let image = cgImage?
            .cropping(to: CGRect(origin: .zero,
                    size: CGSize(width: size.width * scale,
                                 height: (size.height * scale) * pers )))
        else { return nil }
        return UIImage(cgImage: image, scale: 1, orientation: imageOrientation)
    }
    func bottomHalf(pers:CGFloat)-> UIImage? {
        let scaledHight = (size.height * scale)
        guard let image = cgImage?
            .cropping(to: CGRect(origin: CGPoint(x: 0,
                                                 y: scaledHight - (scaledHight * pers).rounded()),
                                 size: CGSize(width: size.width * scale,
                                              height: scaledHight)))
        else {
            
            print("Null")
            
            return nil }
        return UIImage(cgImage: image)
    }
    
    func save(_ name: String) {
//            let path: String = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first!
        let path = try! FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
        
        let url = URL(fileURLWithPath: path.path).appendingPathComponent(name)
        try! self.pngData()?.write(to: url)
            print("saved image at \(url)")
        }
}

你可以这样使用它

let vex = self.view.screenshot(for:  self.view.frame, clipToBounds: true)
            vex .save("full.png") 
            let top = vex.topHalf(pers: 0.2)
            top?.save("Top.png")
            let bottom = vex.bottomHalf(pers: 0.8)
            bottom?.save("bottom.png")

在 1 个函数中截取 2 个不同尺寸图像的屏幕截图

in 1 function take 2 screenshots of different size images

uiview

swift