直接上代码

import Foundation
import SnapKit
import UIKit

// MARK: - GuideContainerView

/// 镂空位置
struct GuideLocation {
    struct Rect {
        /// 镂空尺寸
        var frame: CGRect

        /// 镂空区域圆角半径
        var cornerRadius: CGFloat = 0

        /// 镂空区域水平间距
        var dx: CGFloat = -1

        /// 镂空区域垂直间距
        var dy: CGFloat = -1

        var bPath: UIBezierPath {
            return UIBezierPath(roundedRect: frame.insetBy(dx: dx, dy: dy), cornerRadius: cornerRadius)
        }
    }
    
    var rects: [Rect] = []
    
    var paths: [UIBezierPath] = []
}

/// CoverView 的 子控件布局参考点位
struct Point {
    var minX: CGFloat = 0
    var minY: CGFloat = 0
    var maxX: CGFloat = 0
    var maxY: CGFloat = 0
}

/// 引导view协议
protocol CoverViewProtocol: UIView {
    func layout(make: ConstraintMaker, super: UIView)

    /// 镂空位置
    var location: GuideLocation { get set }

    /// 供 接入方 使用
    var clickAction: ((@escaping (Bool) -> Void) -> Void)? { get set }

    /// 供 GuideContainerView 使用
    var nextStep: (() -> Void)? { get set }
    
    /// 子控件布局参考点位
    var referPoint: Point { get set }
}

/// 引导容器
class GuideContainerView: BaseView {
    public var covers: [CoverViewProtocol] = []
    
    /// 所有 引导图 展示完毕
    public var complete: (() -> Void)?

    private var index: Int = 0
    
    deinit {
        print("GuideContainerView deinit")
    }
    
    override func setupUI() {
        super.setupUI()
        clipsToBounds = true
        backgroundColor = UIColor.black.withAlphaComponent(0.7)
    }

    public func show(in view: UIView? = UIApplication.shared.keyWindow) {
        guard let view = view else { return }
        if covers.isEmpty { return }
        index = 0
        view.addSubview(self)
        snp.makeConstraints { make in
            make.edges.equalToSuperview()
        }

        setNeedsLayout()
        layoutIfNeeded()

        showCover()
    }

    private func showCover() {
        if index < 0 || index > covers.count - 1 {
            complete?()
            removeFromSuperview()
            return
        }

        let cover = covers[index]
        cover.nextStep = { [weak self, weak cover] in
            guard let self = self else { return }
            guard let cover = cover else { return }
            cover.removeFromSuperview()
            self.index += 1
            self.showCover()
        }

        addSubview(cover)
        cover.snp.makeConstraints { [weak self] make in
            guard let self = self else { return }
            cover.layout(make: make, super: self)
        }

        let path = UIBezierPath(rect: bounds)
        if cover.location.rects.isNotEmpty {
            for rect in cover.location.rects {
                path.append(rect.bPath)
            }
        }
        
        if cover.location.paths.isNotEmpty {
            for subPath in cover.location.paths {
                path.append(subPath)
            }
        }

        let shape = CAShapeLayer()
        shape.path = path.cgPath
        shape.fillRule = .evenOdd
        layer.mask = shape
    }
}

// MARK: - CoverView

class CoverView: BaseView, CoverViewProtocol {
    var clickAction: ((@escaping (Bool) -> Void) -> Void)?
    
    var nextStep: (() -> Void)?

    var location = GuideLocation()
    
    var referPoint = Point()

    func layout(make: ConstraintMaker, super: UIView) {
        make.edges.equalToSuperview()
    }
}

举个🌰

1.自定义 CoverView

class HomeFinanceCoverView: CoverView {
    enum Step {
        case s1
    }
    
    var step: Step = .s1
    
    let imgStep = UIImageView().then {
        $0.isUserInteractionEnabled = true
    }
    
    let imgGuide = UIImageView()
    
    deinit {
        print("HomeFinanceCoverView deinit")
    }
    
    override func setupUI() {
        super.setupUI()
        
        addSubview(imgStep)
        addSubview(imgGuide)
        
        imgStep.rx.tapGesture().when(.ended)
            .subscribe(onNext: { [weak self] _ in
                guard let self = self else { return }
                if let clickAction = self.clickAction {
                    clickAction { finish in
                        if finish {
                            self.nextStep?()
                        }
                    }
                } else {
                    self.nextStep?()
                }
            })
            .disposed(by: rx.disposeBag)
    }
    
    override func didMoveToSuperview() {
        super.didMoveToSuperview()

        switch step {
        case .s1:
            imgGuide.image = UIImage(named: "loan_guide_1")
            imgStep.image = UIImage(named: "loan_step_1")
            
            imgGuide.snp.makeConstraints { make in
                make.leading.equalTo(16.shtScale)
                make.size.equalTo(CGSize(width: 178.shtScale, height: 106.shtScale))
                make.top.equalTo(self.referPoint.maxY + 8.shtScale)
            }
            
            imgStep.snp.makeConstraints { make in
                make.centerX.equalToSuperview()
                make.size.equalTo(CGSize(width: 106.shtScale, height: 56.shtScale))
                make.bottom.equalToSuperview().offset(-40.shtScale)
            }
        }
    }
}

2.使用

  let cover = GuideContainerView()
  let cell = ...
  let rect = collectionView.convert(cell.frame, to: UIApplication.shared.keyWindow)
            let c1 = HomeFinanceCoverView().then {
                $0.step = .s1
                $0.referPoint = .init(minX: rect.minX, minY: rect.minY, maxX: rect.maxX, maxY: rect.maxY)
                $0.location.rects = [
                    .init(frame: CGRect(x: rect.minX, y: rect.minY, width: rect.width, height: rect.height), cornerRadius: 6.shtScale)
                ]
            }
            cover.covers.append(c1)     
   cover.show()