Seltsame schwarze Ecken bei Verwendung der Funktion draw (_ rect :)

Question

Wenn ich den Code für mein UIBezierPathInneres in die draw(_ rect:)Funktion einfüge, bekomme ich diese seltsamen, sehr dünnen schwarzen Ecken um die Ansicht und den Schwanz. Beim Ziehen der Ansicht (z. B. innerhalb eines dargestellten Ansichtscontrollers) beginnen diese dünnen Linien ebenfalls zu flackern. Ich nehme an, es ist ein seltsamer Rendering-Fehler. Weiß jemand, ob es eine Möglichkeit gibt, dies zu beheben?

class RenderingView: UIView {
    lazy var backgroundView: UIView = {
        let view = UIView()
        view.layer.cornerRadius = 8
        view.translatesAutoresizingMaskIntoConstraints = false
        return view
    }()

    private lazy var shadowView: UIView = {
        let view = UIView()
        view.translatesAutoresizingMaskIntoConstraints = false
        return view
    }()

    private lazy var textLabel: UILabel = {
        let label = UILabel()
        label.numberOfLines = 0
        label.textAlignment = .center
        label.translatesAutoresizingMaskIntoConstraints = false
        label.text = "Rendering Bug"
        return label
    }()

    override init(frame: CGRect) {
        super.init(frame: frame)
        setup()
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    private func setup() {
        backgroundColor = .clear
        backgroundView.backgroundColor = .yellow
        layer.borderWidth = 0
        setupLayout()
    }

    private func setupLayout() {
        [shadowView, backgroundView, textLabel].forEach(addSubview)

        backgroundView.leadingAnchor.constraint(equalTo: leadingAnchor).isActive = true
        backgroundView.topAnchor.constraint(equalTo: topAnchor).isActive = true
        backgroundView.trailingAnchor.constraint(equalTo: trailingAnchor).isActive = true
        backgroundView.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true

        shadowView.leadingAnchor.constraint(equalTo: backgroundView.leadingAnchor).isActive = true
        shadowView.topAnchor.constraint(equalTo: backgroundView.topAnchor).isActive = true
        shadowView.trailingAnchor.constraint(equalTo: backgroundView.trailingAnchor).isActive = true
        shadowView.bottomAnchor.constraint(equalTo: backgroundView.bottomAnchor).isActive = true

        textLabel.leadingAnchor.constraint(equalTo: backgroundView.leadingAnchor, constant: 10).isActive = true
        textLabel.trailingAnchor.constraint(equalTo: backgroundView.trailingAnchor, constant: -10).isActive = true
        textLabel.topAnchor.constraint(equalTo: backgroundView.topAnchor, constant: 10).isActive = true
        textLabel.bottomAnchor.constraint(equalTo: backgroundView.bottomAnchor, constant: -10).isActive = true
    }

    override func draw(_ rect: CGRect) {
        shapeBackground()
    }

    private func shapeBackground() {
        let tailLayer = CAShapeLayer()

        let bezierPath = UIBezierPath(roundedRect: CGRect(x: backgroundView.bounds.minX,
                                                          y: backgroundView.bounds.minY,
                                                          width: backgroundView.bounds.width,
                                                          height: backgroundView.bounds.height - 12),
                                      cornerRadius: 8)

        let shadowBezierPath = UIBezierPath(roundedRect: CGRect(x: backgroundView.bounds.minX + 5,
                                                                y: backgroundView.bounds.minY + 10,
                                                                width: backgroundView.bounds.width - 10,
                                                                height: backgroundView.bounds.height - 12 - 10),
                                            cornerRadius: 8)

        [bezierPath, shadowBezierPath].forEach {
            $0.move(to: CGPoint(x: backgroundView.bounds.midX - 12, y: backgroundView.bounds.maxY - 12)) $0.addLine(to: CGPoint(x: backgroundView.bounds.midX, y: backgroundView.bounds.maxY))
            $0.addLine(to: CGPoint(x: backgroundView.bounds.midX + 12, y: backgroundView.bounds.maxY - 12)) $0.fill()
            $0.close()
        }

        tailLayer.path = bezierPath.cgPath
        tailLayer.fillColor = UIColor.white.cgColor

        shadowView.layer.shadowPath = shadowBezierPath.cgPath
        shadowView.layer.cornerRadius = 8

        backgroundView.layer.masksToBounds = true
        backgroundView.layer.mask = tailLayer
    }
}

EDIT: Es stellte sich heraus, dass ich addClip()die Bezierpfade verwenden musste, um diese Ecken loszuwerden

Answer 1

Sie sind sich nicht sicher, ob Sie dies anstreben, aber es sieht einwandfrei aus, wenn Sie die shapeBackground()Methode verlassen draw(_ rect:)und einige geringfügige Änderungen vornehmen.

Ich habe einige Ihrer Zeichenroutinen im Inneren geändert shapeBackground()und die Funktion verschoben layoutSubviews(), um die Position des Hecks aus dem durch Einschränkungen erstellten Rahmen zu berechnen. Ich habe auch einige Variablen für tailWidth, & hinzugefügt tailHeight.

Wie so:

class RenderingView: UIView {
    lazy var backgroundView: UIView = {
        let view = UIView()
        view.layer.cornerRadius = 8
        view.translatesAutoresizingMaskIntoConstraints = false
        return view
    }()
    
    private lazy var shadowView: UIView = {
        let view = UIView()
        view.translatesAutoresizingMaskIntoConstraints = false
        return view
    }()
    
    private lazy var textLabel: UILabel = {
        let label = UILabel()
        label.numberOfLines = 0
        label.textAlignment = .center
        label.translatesAutoresizingMaskIntoConstraints = false
        label.text = "No Rendering Bug"
        return label
    }()
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        setup()
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    private func setup() {
        backgroundColor = .clear
        backgroundView.backgroundColor = .systemTeal
        //backgroundView.frame.size = CGSize(width: 100, height: 100)
        layer.borderWidth = 0
        setupLayout()
    }
    
    private func setupLayout() {
        [shadowView, backgroundView, textLabel].forEach(addSubview)
        
        backgroundView.leadingAnchor.constraint(equalTo: leadingAnchor).isActive = true
        backgroundView.topAnchor.constraint(equalTo: topAnchor).isActive = true
        backgroundView.trailingAnchor.constraint(equalTo: trailingAnchor).isActive = true
        backgroundView.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true
        
        shadowView.leadingAnchor.constraint(equalTo: backgroundView.leadingAnchor).isActive = true
        shadowView.topAnchor.constraint(equalTo: backgroundView.topAnchor).isActive = true
        shadowView.trailingAnchor.constraint(equalTo: backgroundView.trailingAnchor).isActive = true
        shadowView.bottomAnchor.constraint(equalTo: backgroundView.bottomAnchor).isActive = true
        
        textLabel.leadingAnchor.constraint(equalTo: backgroundView.leadingAnchor, constant: 10).isActive = true
        textLabel.trailingAnchor.constraint(equalTo: backgroundView.trailingAnchor, constant: -10).isActive = true
        textLabel.topAnchor.constraint(equalTo: backgroundView.topAnchor, constant: 10).isActive = true
        textLabel.bottomAnchor.constraint(equalTo: backgroundView.bottomAnchor, constant: -10).isActive = true
        
        
    }
    
    override func didMoveToWindow() {
        super.didMoveToWindow()
        
    }
    
    override func layoutSubviews() {
        super.layoutSubviews()
        
        shapeBackground(color: UIColor.systemTeal)
    }
    
    override func draw(_ rect: CGRect) {
        super.draw(rect)
        
    }
    
    private func shapeBackground(color: UIColor) {
        let tailLayer = CAShapeLayer()
        tailLayer.name = "tailLayer"
        
        let tailWidth: CGFloat = 16
        let tailHeight: CGFloat = 10
        
        let bezierPath = UIBezierPath()
        let shadowBezierPath = UIBezierPath()
        
        [bezierPath, shadowBezierPath].forEach {
            $0.move(to: CGPoint(x: 0, y: 0)) $0.addLine(to: CGPoint(x: tailWidth / 2, y: tailHeight))
            $0.addLine(to: CGPoint(x: tailWidth, y: 0)) $0.fill()
            $0.close()
        }
        
        tailLayer.path = bezierPath.cgPath
        tailLayer.fillColor = color.cgColor
        
        shadowView.layer.shadowPath = shadowBezierPath.cgPath
        shadowView.layer.cornerRadius = 8
        
        print(backgroundView.bounds.width)
        
        tailLayer.frame = CGRect(x: (backgroundView.bounds.width - tailWidth) / 2,
                                 y: backgroundView.bounds.maxY,
                                 width: tailWidth,
                                 height: tailHeight)
        
        backgroundView.layer.masksToBounds = false
        backgroundView.layer.addSublayer(tailLayer)
    }
}