ios - 如何将镜像添加到 2d Box 角

Question

你好 friend 我需要在右下角和底部添加镜像。 我在这个答案的帮助下创建了 View 类型

how to create a view like this shape in swift?

但是我无法在右下角和底部添加图片

Answer 1

当前的方法与 previous 有所不同一个。

之前我已经绘制了右下角并调整了图像的大小，这样外观就在 question 中被询问了。 .

但在这个问题中，这种方法将不再有效。第一个原因是 draw(in rect: CGRect) 在绘制时不提供镜像功能。 iOS 仅提供在 UIImageView 中绘制时的镜像功能。所以要进行镜像，我们需要设置 3 个 ImageView 。

所以实现它的方法如下

1. 将一个 UIImageView 放在中间。
2. 将一个 UIImageView 放在中间的右侧，另一个放在底部。
3. 现在计算正确的镜像并应用剪切正确的 ImageView 。
4. 对底部做同样的事情。

上述方法仍然存在一个问题。例如，我们根据 y 轴剪切右 ImageView 。剪切操作与中心一起工作。所以左侧和右侧都穿过 y 轴。所以我们将正向转换为 x 轴，以便所有剪切都适用于 UIImageView 的右侧。 这就是为什么重叠右侧和主 ImageView 以填补之间的空隙，如下所示

rightImageView.leadingAnchor.constraint(equalTo: mainImageView.trailingAnchor, constant: -stripSize / 2),

底部 ImageView 也是如此。

代码

lass ViewController: UIViewController {

    let mainImageView: UIImageView = {
        let view = UIImageView()
        view.translatesAutoresizingMaskIntoConstraints = false
        view.clipsToBounds = true
        return view
    }()
    let rightImageView: UIImageView = {
        let view = UIImageView()
        view.translatesAutoresizingMaskIntoConstraints = false
        view.clipsToBounds = true
        return view
    }()
    let bottomImageView: UIImageView = {
        let view = UIImageView()
        view.translatesAutoresizingMaskIntoConstraints = false
        view.clipsToBounds = true
        return view
    }()

    let rightDarkView: UIView = {
        let view = UIView()
        view.translatesAutoresizingMaskIntoConstraints = false
        view.backgroundColor = UIColor.init(red: 0, green: 0, blue: 0, alpha: 0.4)
        return view
    }()

    let bottomDarkView: UIView = {
        let view = UIView()
        view.translatesAutoresizingMaskIntoConstraints = false
        view.backgroundColor = UIColor.init(red: 0, green: 0, blue: 0, alpha: 0.5)
        return view
    }()


    let mainImageSize = CGSize(width: 240, height: 240)
    let stripSize = CGFloat(20)


    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.

        setupView()
        setupMirroView()
    }



    func setupView() {
        view.addSubview(mainImageView)
        view.addSubview(rightImageView)
        view.addSubview(bottomImageView)

        view.addSubview(rightDarkView)
        view.addSubview(bottomDarkView)

        NSLayoutConstraint.activate([
            mainImageView.centerXAnchor.constraint(equalTo: view.centerXAnchor),
            mainImageView.centerYAnchor.constraint(equalTo: view.centerYAnchor),
            mainImageView.widthAnchor.constraint(equalToConstant: mainImageSize.width),
            mainImageView.heightAnchor.constraint(equalToConstant: mainImageSize.height),

            rightImageView.leadingAnchor.constraint(equalTo: mainImageView.trailingAnchor, constant: -stripSize / 2),
            rightImageView.topAnchor.constraint(equalTo: mainImageView.topAnchor),
            rightImageView.bottomAnchor.constraint(equalTo: mainImageView.bottomAnchor),
            rightImageView.widthAnchor.constraint(equalToConstant: stripSize),

            rightDarkView.leadingAnchor.constraint(equalTo: rightImageView.leadingAnchor),
            rightDarkView.topAnchor.constraint(equalTo: rightImageView.topAnchor),
            rightDarkView.trailingAnchor.constraint(equalTo: rightImageView.trailingAnchor),
            rightDarkView.bottomAnchor.constraint(equalTo: rightImageView.bottomAnchor),

            bottomImageView.topAnchor.constraint(equalTo: mainImageView.bottomAnchor, constant: -stripSize / 2),
            bottomImageView.leadingAnchor.constraint(equalTo: mainImageView.leadingAnchor),
            bottomImageView.trailingAnchor.constraint(equalTo: mainImageView.trailingAnchor),
            bottomImageView.heightAnchor.constraint(equalToConstant: stripSize),

            bottomDarkView.leadingAnchor.constraint(equalTo: bottomImageView.leadingAnchor),
            bottomDarkView.topAnchor.constraint(equalTo: bottomImageView.topAnchor),
            bottomDarkView.trailingAnchor.constraint(equalTo: bottomImageView.trailingAnchor),
            bottomDarkView.bottomAnchor.constraint(equalTo: bottomImageView.bottomAnchor)

            ])
    }

    func setupMirroView() {
        let image = UIImage(named: "image")
        mainImageView.image = image

        // prepare the image for the right image view
        let rightImage = image?.cropped(to: CGSize(width: stripSize, height: mainImageSize.height),
                                        drawInto: CGRect(x: stripSize - mainImageSize.width, y: 0, width: mainImageSize.width, height: mainImageSize.height))
        let rightImageMirrored = UIImage(cgImage: rightImage!.cgImage!, scale: 1.0, orientation: .upMirrored)
        rightImageView.image = rightImageMirrored

        var rightTransform = CGAffineTransform.identity
        rightTransform = rightTransform.translatedBy(x: stripSize / 2, y: 0)
        rightTransform = rightTransform.concatenating(CGAffineTransform(a: 1.0, b: 1.0, c: 0.0, d: 1.0, tx: 0.0, ty: 0.0))
        rightImageView.transform = rightTransform
        rightDarkView.transform = rightTransform


        // prepare the image for the left image view
        let downImage = image?.cropped(to: CGSize(width: mainImageSize.width, height: stripSize),
                                       drawInto: CGRect(x: 0, y: stripSize - mainImageSize.height, width: mainImageSize.width, height: mainImageSize.height))
        let downImageMirroed = UIImage(cgImage: downImage!.cgImage!, scale: 1.0, orientation: .downMirrored)
        bottomImageView.image = downImageMirroed

        var downTransform = CGAffineTransform.identity
        downTransform = downTransform.translatedBy(x: 0, y: stripSize / 2)
        downTransform = downTransform.concatenating(__CGAffineTransformMake(1.0, 0.0, 1.0, 1.0, 0.0, 0.0))
        bottomImageView.transform = downTransform
        bottomDarkView.transform = downTransform

    }

}

extension UIImage {
    func cropped(to size: CGSize, drawInto: CGRect) -> UIImage {
        UIGraphicsBeginImageContext(size)
        self.draw(in: drawInto)
        let newImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return newImage!
    }
}

输出