Swift Image自定义多点裁剪和保存

Question

我正在尝试实现将Image和camera拍摄的图库捕获的图像移至照片编辑ViewController。在这里，我需要实现多点可调cropping功能。

我正在研究好的初始化示例，所以现在我没有裁剪代码。

请提供想法或示例代码。

Answer 1

这是我的代码，希望您已经创建了相机视图。

import UIKit

internal class CropOverlay: UIView {

    var outerLines = [UIView]()
    var horizontalLines = [UIView]()
    var verticalLines = [UIView]()

    var topLeftCornerLines = [UIView]()
    var topRightCornerLines = [UIView]()
    var bottomLeftCornerLines = [UIView]()
    var bottomRightCornerLines = [UIView]()

    var cornerButtons = [UIButton]()

    let cornerLineDepth: CGFloat = 3
    let cornerLineWidth: CGFloat = 22.5
    var cornerButtonWidth: CGFloat {
        return self.cornerLineWidth * 2
    }

    let lineWidth: CGFloat = 1

    let outterGapRatio: CGFloat = 1/3
    var outterGap: CGFloat {
        return self.cornerButtonWidth * self.outterGapRatio
    }

    var isResizable: Bool = false
    var isMovable: Bool = false
    var minimumSize: CGSize = CGSize.zero

    internal override init(frame: CGRect) {
        super.init(frame: frame)
        createLines()
    }

    internal required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        createLines()
    }

    override func layoutSubviews() {

        for i in 0..<outerLines.count {
            let line = outerLines[i]
            var lineFrame: CGRect
            switch (i) {
            case 0:
                lineFrame = CGRect(x: outterGap, y: outterGap, width: bounds.width - outterGap * 2, height: lineWidth)
                break
            case 1:
                lineFrame = CGRect(x: bounds.width - lineWidth - outterGap, y: outterGap, width: lineWidth, height: bounds.height - outterGap * 2)
                break
            case 2:
                lineFrame = CGRect(x: outterGap, y: bounds.height - lineWidth - outterGap, width: bounds.width - outterGap * 2, height: lineWidth)
                break
            case 3:
                lineFrame = CGRect(x: outterGap, y: outterGap, width: lineWidth, height: bounds.height - outterGap * 2)
                break
            default:
                lineFrame = CGRect.zero
                break
            }

            line.frame = lineFrame
        }

        let corners = [topLeftCornerLines, topRightCornerLines, bottomLeftCornerLines, bottomRightCornerLines]
        for i in 0..<corners.count {
            let corner = corners[i]

            var horizontalFrame: CGRect
            var verticalFrame: CGRect
            var buttonFrame: CGRect
            let buttonSize = CGSize(width: cornerButtonWidth, height: cornerButtonWidth)

            switch (i) {
            case 0: // Top Left
                verticalFrame = CGRect(x: outterGap, y: outterGap, width: cornerLineDepth, height: cornerLineWidth)
                horizontalFrame = CGRect(x: outterGap, y: outterGap, width: cornerLineWidth, height: cornerLineDepth)
                buttonFrame = CGRect(origin: CGPoint(x: 0, y: 0), size: buttonSize)
            case 1: // Top Right
                verticalFrame = CGRect(x: bounds.width - cornerLineDepth - outterGap, y: outterGap, width: cornerLineDepth, height: cornerLineWidth)
                horizontalFrame = CGRect(x: bounds.width - cornerLineWidth - outterGap, y: outterGap, width: cornerLineWidth, height: cornerLineDepth)
                buttonFrame = CGRect(origin: CGPoint(x: bounds.width - cornerButtonWidth, y: 0), size: buttonSize)
            case 2: // Bottom Left
                verticalFrame = CGRect(x: outterGap, y:  bounds.height - cornerLineWidth - outterGap, width: cornerLineDepth, height: cornerLineWidth)
                horizontalFrame = CGRect(x: outterGap, y:  bounds.height - cornerLineDepth - outterGap, width: cornerLineWidth, height: cornerLineDepth)
                buttonFrame = CGRect(origin: CGPoint(x: 0, y: bounds.height - cornerButtonWidth), size: buttonSize)
            case 3: // Bottom Right
                verticalFrame = CGRect(x: bounds.width - cornerLineDepth - outterGap, y: bounds.height - cornerLineWidth - outterGap, width: cornerLineDepth, height: cornerLineWidth)
                horizontalFrame = CGRect(x: bounds.width - cornerLineWidth - outterGap, y: bounds.height - cornerLineDepth - outterGap, width: cornerLineWidth, height: cornerLineDepth)
                buttonFrame = CGRect(origin: CGPoint(x: bounds.width - cornerButtonWidth, y: bounds.height - cornerButtonWidth), size: buttonSize)

            default:
                verticalFrame = CGRect.zero
                horizontalFrame = CGRect.zero
                buttonFrame = CGRect.zero
            }

            corner[0].frame = verticalFrame
            corner[1].frame = horizontalFrame
            cornerButtons[i].frame = buttonFrame
        }

        let lineThickness = lineWidth / UIScreen.main.scale
        let vPadding = (bounds.height - outterGap * 2 - (lineThickness * CGFloat(horizontalLines.count))) / CGFloat(horizontalLines.count + 1)
        let hPadding = (bounds.width - outterGap * 2 - (lineThickness * CGFloat(verticalLines.count))) / CGFloat(verticalLines.count + 1)

        for i in 0..<horizontalLines.count {
            let hLine = horizontalLines[i]
            let vLine = verticalLines[i]

            let vSpacing = (vPadding * CGFloat(i + 1)) + (lineThickness * CGFloat(i))
            let hSpacing = (hPadding * CGFloat(i + 1)) + (lineThickness * CGFloat(i))

            hLine.frame = CGRect(x: outterGap, y: vSpacing + outterGap, width: bounds.width - outterGap * 2, height:  lineThickness)
            vLine.frame = CGRect(x: hSpacing + outterGap, y: outterGap, width: lineThickness, height: bounds.height - outterGap * 2)
        }

    }

    func createLines() {

        outerLines = [createLine(), createLine(), createLine(), createLine()]
        horizontalLines = [createLine(), createLine()]
        verticalLines = [createLine(), createLine()]

        topLeftCornerLines = [createLine(), createLine()]
        topRightCornerLines = [createLine(), createLine()]
        bottomLeftCornerLines = [createLine(), createLine()]
        bottomRightCornerLines = [createLine(), createLine()]

        cornerButtons = [createButton(), createButton(), createButton(), createButton()]

        let dragGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(moveCropOverlay))
        addGestureRecognizer(dragGestureRecognizer)
    }

    func createLine() -> UIView {
        let line = UIView()
        line.backgroundColor = UIColor.white
        addSubview(line)
        return line
    }

    func createButton() -> UIButton {
        let button = UIButton()
        button.backgroundColor = UIColor.clear

        let dragGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(moveCropOverlay))
        button.addGestureRecognizer(dragGestureRecognizer)

        addSubview(button)
        return button
    }

    @objc func moveCropOverlay(gestureRecognizer: UIPanGestureRecognizer) {
        if isResizable, let button = gestureRecognizer.view as? UIButton {
            if gestureRecognizer.state == .began || gestureRecognizer.state == .changed {
                let translation = gestureRecognizer.translation(in: self)

                var newFrame: CGRect

                switch button {
                case cornerButtons[0]:  // Top Left
                    newFrame = CGRect(x: frame.origin.x + translation.x, y: frame.origin.y + translation.y, width: frame.size.width - translation.x, height: frame.size.height - translation.y)
                case cornerButtons[1]:  // Top Right
                    newFrame = CGRect(x: frame.origin.x, y: frame.origin.y + translation.y, width: frame.size.width + translation.x, height: frame.size.height - translation.y)
                case cornerButtons[2]:  // Bottom Left
                    newFrame = CGRect(x: frame.origin.x + translation.x, y: frame.origin.y, width: frame.size.width - translation.x, height: frame.size.height + translation.y)
                case cornerButtons[3]:  // Bottom Right
                    newFrame = CGRect(x: frame.origin.x, y: frame.origin.y, width: frame.size.width + translation.x, height: frame.size.height + translation.y)
                default:
                    newFrame = CGRect.zero
                }

                let minimumFrame = CGRect(x: newFrame.origin.x, y: newFrame.origin.y, width: max(newFrame.size.width, minimumSize.width + 2 * outterGap), height: max(newFrame.size.height, minimumSize.height + 2 * outterGap))
                frame = minimumFrame
                layoutSubviews()

                gestureRecognizer.setTranslation(CGPoint.zero, in: self)
            }
        } else if isMovable {
            if gestureRecognizer.state == .began || gestureRecognizer.state == .changed {
                let translation = gestureRecognizer.translation(in: self)

                gestureRecognizer.view!.center = CGPoint(x: gestureRecognizer.view!.center.x + translation.x, y: gestureRecognizer.view!.center.y + translation.y)
                gestureRecognizer.setTranslation(CGPoint(x: 0, y: 0), in: self)
            }
        }
    }

    override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        let view = super.hitTest(point, with: event)

        if !isMovable && isResizable && view != nil {
            let isButton = cornerButtons.reduce(false) { $1.hitTest(convert(point, to: $1), with: event) != nil || $0 }
            if !isButton {
                return nil
            }
        }

        return view
    }
}

它是Swift 4.0版本，但也适用于Swift 4.2 / 5.0