UIViewの周りの破線の境界線

の周りに破線の境界線を追加するにはどうすればよいですかUIView。

このようなもの

以下の例のように、レイヤーとベジェパスを使用して、このパターンでボーダーを設定できます。

Objective-C

CAShapeLayer *yourViewBorder = [CAShapeLayer layer];
yourViewBorder.strokeColor = [UIColor blackColor].CGColor;
yourViewBorder.fillColor = nil;
yourViewBorder.lineDashPattern = @[@2, @2];
yourViewBorder.frame = yourView.bounds;
yourViewBorder.path = [UIBezierPath bezierPathWithRect:yourView.bounds].CGPath;
[yourView.layer addSublayer:yourViewBorder];

Swift 3.1

var yourViewBorder = CAShapeLayer()
yourViewBorder.strokeColor = UIColor.black.cgColor
yourViewBorder.lineDashPattern = [2, 2]
yourViewBorder.frame = yourView.bounds
yourViewBorder.fillColor = nil
yourViewBorder.path = UIBezierPath(rect: yourView.bounds).cgPath
yourView.layer.addSublayer(yourViewBorder)

以下の例のようなパターン画像を使用して、さまざまなタイプのデザインを設定することもできます。

[yourView.layer setBorderWidth:5.0];
[yourView.layer setBorderColor:[[UIColor colorWithPatternImage:[UIImage imageNamed:@"DotedImage.png"]] CGColor]];///just add image name and create image with dashed or doted drawing and add here

ここで<QuartzCore/QuartzCore>は、プロジェクトにフレームワークを追加し、YourViewController.mファイル内の以下の行でそれをインポートします。

#import <QuartzCore/QuartzCore.h>

サブレイヤーが必要な場合の別の方法。カスタムビューのinitに、これを入れます（_borderはivarです）：

_border = [CAShapeLayer layer];
_border.strokeColor = [UIColor colorWithRed:67/255.0f green:37/255.0f blue:83/255.0f alpha:1].CGColor;
_border.fillColor = nil;
_border.lineDashPattern = @[@4, @2];
[self.layer addSublayer:_border];

そしてあなたのlayoutsubviewsにこれを入れてください：

_border.path = [UIBezierPath bezierPathWithRect:self.bounds].CGPath;
_border.frame = self.bounds;

Swiftで作業している人のために、UIViewのこのクラス拡張はそれを簡単にします。これは、sunshineDevの回答に基づいていました。

extension UIView {
  func addDashedBorder() {
    let color = UIColor.red.cgColor

    let shapeLayer:CAShapeLayer = CAShapeLayer()
    let frameSize = self.frame.size
    let shapeRect = CGRect(x: 0, y: 0, width: frameSize.width, height: frameSize.height)

    shapeLayer.bounds = shapeRect
    shapeLayer.position = CGPoint(x: frameSize.width/2, y: frameSize.height/2)
    shapeLayer.fillColor = UIColor.clear.cgColor
    shapeLayer.strokeColor = color
    shapeLayer.lineWidth = 2
    shapeLayer.lineJoin = CAShapeLayerLineJoin.round
    shapeLayer.lineDashPattern = [6,3]
    shapeLayer.path = UIBezierPath(roundedRect: shapeRect, cornerRadius: 5).cgPath

    self.layer.addSublayer(shapeLayer)
    }
}

それを使用するには：

anyView.addDashedBorder()

スウィフト3：

import UIKit

class UIViewWithDashedLineBorder: UIView {

    override func draw(_ rect: CGRect) {

        let path = UIBezierPath(roundedRect: rect, cornerRadius: 0)

        UIColor.purple.setFill()
        path.fill()

        UIColor.orange.setStroke()
        path.lineWidth = 5

        let dashPattern : [CGFloat] = [10, 4]
        path.setLineDash(dashPattern, count: 2, phase: 0)
        path.stroke()
    }
}

ストーリーボードで（カスタムクラスとして）、またはコードで直接使用します。

let v = UIViewWithDashedLineBorder(frame: CGRect(x: 0, y: 0, width: 100, height: 100))

結果：

Prasad Gの提案に基づいて、UIImage Extrasクラス内に次のメソッドを作成しました。

- (CAShapeLayer *) addDashedBorderWithColor: (CGColorRef) color {
    CAShapeLayer *shapeLayer = [CAShapeLayer layer];

    CGSize frameSize = self.size;

    CGRect shapeRect = CGRectMake(0.0f, 0.0f, frameSize.width, frameSize.height);
    [shapeLayer setBounds:shapeRect];
    [shapeLayer setPosition:CGPointMake( frameSize.width/2,frameSize.height/2)];

    [shapeLayer setFillColor:[[UIColor clearColor] CGColor]];
    [shapeLayer setStrokeColor:color];
    [shapeLayer setLineWidth:5.0f];
    [shapeLayer setLineJoin:kCALineJoinRound];
    [shapeLayer setLineDashPattern:
     [NSArray arrayWithObjects:[NSNumber numberWithInt:10],
      [NSNumber numberWithInt:5],
      nil]];
    UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:shapeRect cornerRadius:15.0];
    [shapeLayer setPath:path.CGPath];

    return shapeLayer;
}

形状の位置を（0,0）として定義すると、境界線の下部の隅が画像の中心に配置されることを指摘することが重要です。そのため、（frameSize.width / 2、frameSize .height / 2）

次に、このメソッドを使用して、UIImageViewのUIImageを使用して破線の境界線を取得し、UIImageViewレイヤーのサブレイヤーとしてCAShapeLayerを追加します。

[myImageView.layer addSublayer:[myImageView.image addDashedBorderWithColor:[[UIColor whiteColor] CGColor]]];

CGContextSetLineDash（）メソッドを使用します。

CGFloat dashPattern[]= {3.0, 2};

context =UIGraphicsGetCurrentContext();
CGContextSetRGBStrokeColor(context, 1.0, 1.0, 1.0, 1.0);
// And draw with a blue fill color
CGContextSetRGBFillColor(context, 0.0, 0.0, 1.0, 1.0);
// Draw them with a 2.0 stroke width so they are a bit more visible.
CGContextSetLineWidth(context, 4.0);
CGContextSetLineDash(context, 0.0, dashPattern, 2);

CGContextAddRect(context, self.bounds);

// Close the path
CGContextClosePath(context);

CGContextStrokePath(context);

// Fill & stroke the path
CGContextDrawPath(context, kCGPathFillStroke);

参考になると思います。

以下は、任意のプロジェクトで機能するUIViewサブクラスです。ラウンドビューでも機能します。

import UIKit

class CustomDashedView: UIView {

    @IBInspectable var cornerRadius: CGFloat = 0 {
        didSet {
            layer.cornerRadius = cornerRadius
            layer.masksToBounds = cornerRadius > 0
        }
    }
    @IBInspectable var dashWidth: CGFloat = 0
    @IBInspectable var dashColor: UIColor = .clear
    @IBInspectable var dashLength: CGFloat = 0
    @IBInspectable var betweenDashesSpace: CGFloat = 0

    var dashBorder: CAShapeLayer?

    override func layoutSubviews() {
        super.layoutSubviews()
        dashBorder?.removeFromSuperlayer()
        let dashBorder = CAShapeLayer()
        dashBorder.lineWidth = dashWidth
        dashBorder.strokeColor = dashColor.cgColor
        dashBorder.lineDashPattern = [dashLength, betweenDashesSpace] as [NSNumber]
        dashBorder.frame = bounds
        dashBorder.fillColor = nil
        if cornerRadius > 0 {
            dashBorder.path = UIBezierPath(roundedRect: bounds, cornerRadius: cornerRadius).cgPath
        } else {
            dashBorder.path = UIBezierPath(rect: bounds).cgPath
        }
        layer.addSublayer(dashBorder)
        self.dashBorder = dashBorder
    }
}

このようにして、ストーリーボードから次のように編集できます。

結果のペア：

このためには、その特定のオブジェクトにCAShapeLayerを追加する必要があります

 CAShapeLayer * dotborder = [CAShapeLayer layer];
    dotborder.strokeColor = [UIColor redColor].CGColor;//your own color
    dotborder.fillColor = nil;
    dotborder.lineDashPattern = @[@4, @2];//your own patten 
    [codeBtn.layer addSublayer:dotborder];
    dotborder.path = [UIBezierPath bezierPathWithRect:codeBtn.bounds].CGPath;
    dotborder.frame = codeBtn.bounds;

Swift 4.2

UIViewデフォルト値が設定された構成可能なパラメーターを持つ拡張としてのrmooneyの回答に基づいています。

ビューが持っている場合、これは機能しないことに注意してください self.translatesAutoresizingMaskIntoConstraints = false

extension UIView {
  func addDashedBorder(_ color: UIColor = UIColor.black, withWidth width: CGFloat = 2, cornerRadius: CGFloat = 5, dashPattern: [NSNumber] = [3,6]) {

    let shapeLayer = CAShapeLayer()

    shapeLayer.bounds = bounds
    shapeLayer.position = CGPoint(x: bounds.width/2, y: bounds.height/2)
    shapeLayer.fillColor = nil
    shapeLayer.strokeColor = color.cgColor
    shapeLayer.lineWidth = width
    shapeLayer.lineJoin = CAShapeLayerLineJoin.round // Updated in swift 4.2
    shapeLayer.lineDashPattern = dashPattern
    shapeLayer.path = UIBezierPath(roundedRect: bounds, cornerRadius: cornerRadius).cgPath

    self.layer.addSublayer(shapeLayer)
  }
}

QuartzCore回答のSwiftバージョン。

import QuartzCore    

let dottedPattern = UIImage(named: "dottedPattern")
myView.layer.borderWidth = 1
myView.layer.borderColor = UIColor(patternImage: dottedPattern!).CGColor

CAShapeLayerアプローチの作品が、QuartzCoreアプローチならば、テーブルビューのリロードを扱うに優れているUIViewセルの内側にあります。

画像の場合、次のようなものを使用できます（非常に小さい）。

私はそれを回避できるときはPNGよりもベクターを好む傾向があります。

• スケッチ内で、4x4ピクセルの長方形を作成します。
• 全部で4つ作る
• それらをフォースクエアの交互の色にグループ化する
• グループをPDFとしてエクスポート
• 内Images.xcassetsで、New Image Set呼び出されたdottedPatternを作成します。
• 変更Scale FactorsへSingle Vector
• PDFをドロップ

Xamarin.iOSの破線/点線のボーダー。

        dottedLayer = new CAShapeLayer();
        dottedLayer.StrokeColor = UIColor.FromRGB(202, 202, 208).CGColor; 
        dottedLayer.FillColor = null;
        dottedLayer.LineDashPattern = new[] { new NSNumber(4), new NSNumber(2) };

        dottedLayer.Path = UIBezierPath.FromRect(YourView.Bounds).CGPath; //for square
        dottedLayer.Path = UIBezierPath.FromRoundedRect(YourView.Bounds, 5).CGPath; //for rounded corners

        dottedLayer.Frame = YourView.Bounds;
        YourView.Layer.AddSublayer(dottedLayer);

ではスウィフト3

let border = CAShapeLayer();
border.strokeColor = UIColor.black.cgColor;
border.fillColor = nil;
border.lineDashPattern = [4, 4];
border.path = UIBezierPath(rect: theView.bounds).cgPath
border.frame = theView.bounds;
theView.layer.addSublayer(border);

これは、Swift 2で必要な場合

func addDashedLineBorderWithColor(color:UIColor) {
    let _ = self.sublayers?.filter({$0.name == "DashedBorder"}).map({$0.removeFromSuperlayer()})
    let  border = CAShapeLayer();
    border.name = "DashedBorder"
    border.strokeColor = color.CGColor;
    border.fillColor = nil;
    border.lineDashPattern = [4, 4];
    border.path = UIBezierPath(rect: self.bounds).CGPath
    border.frame = self.bounds;
    self.addSublayer(border);

}

以下のコードを試してください

- (void)drawRect:(CGRect)rect {
    //// Color Declarations
    UIColor* fillColor = [UIColor colorWithRed: 1 green: 1 blue: 1 alpha: 1];
    UIColor* strokeColor = [UIColor colorWithRed: 0.29 green: 0.565 blue: 0.886 alpha: 1];

    //// Rectangle Drawing
    UIBezierPath* rectanglePath = [UIBezierPath bezierPathWithRoundedRect:rect cornerRadius: 6];
    [fillColor setFill];
    [rectanglePath fill];
    [strokeColor setStroke];
    rectanglePath.lineWidth = 1;
    CGFloat rectanglePattern[] = {6, 2, 6, 2};
    [rectanglePath setLineDash: rectanglePattern count: 4 phase: 0];
    [rectanglePath stroke];
    [super drawRect:rect];
}

うなり声のような人のために

Swift 5の場合

extension UIView {
    func addDashBorder() {
        let color = UIColor.white.cgColor

        let shapeLayer:CAShapeLayer = CAShapeLayer()

        let frameSize = self.frame.size
        let shapeRect = CGRect(x: 0, y: 0, width: frameSize.width, height: frameSize.height)

        shapeLayer.bounds = shapeRect
        shapeLayer.name = "DashBorder"
        shapeLayer.position = CGPoint(x: frameSize.width/2, y: frameSize.height/2)
        shapeLayer.fillColor = UIColor.clear.cgColor
        shapeLayer.strokeColor = color
        shapeLayer.lineWidth = 1.5
        shapeLayer.lineJoin = .round
        shapeLayer.lineDashPattern = [2,4]
        shapeLayer.path = UIBezierPath(roundedRect: shapeRect, cornerRadius: 10).cgPath

        self.layer.masksToBounds = false

        self.layer.addSublayer(shapeLayer)
    }
}

追加する方法

vw.addDashBorder()

再度ボーダーを削除する方法

let _ = vw.layer.sublayers?.filter({$0.name == "DashBorder"}).map({$0.removeFromSuperlayer()})

@Chris実装の一部を使用してIB Designableを作成することになりました。

CurvedDashedBorderUIVIew.h：

#import <UIKit/UIKit.h>

IB_DESIGNABLE
@interface CurvedDashedBorderUIVIew : UIView

@property (nonatomic) IBInspectable CGFloat cornerRadius;
@property (nonatomic) IBInspectable UIColor *borderColor;
@property (nonatomic) IBInspectable int dashPaintedSize;
@property (nonatomic) IBInspectable int dashUnpaintedSize;

@property (strong, nonatomic) CAShapeLayer *border;

@end

CurvedDashedBorderUIVIew.m：

#import "CurvedDashedBorderUIVIew.h"

@implementation CurvedDashedBorderUIVIew

- (instancetype)init
{
    self = [super init];
    if (self) {
        [self setup];
    }
    return self;
}

- (instancetype)initWithCoder:(NSCoder *)coder
{
    self = [super initWithCoder:coder];
    if (self) {
        [self setup];
    }
    return self;
}

- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        [self setup];
    }
    return self;
}

-(void)setup
{
    _border = [CAShapeLayer layer];
    [self.layer addSublayer:_border];
}

-(void)layoutSubviews {
    [super layoutSubviews];
    self.layer.cornerRadius = self.cornerRadius;

    _border.strokeColor = self.borderColor.CGColor;
    _border.fillColor = nil;
    _border.lineDashPattern = @[[NSNumber numberWithInt:_dashPaintedSize],
                                [NSNumber numberWithInt:_dashUnpaintedSize]];
    _border.path = [UIBezierPath bezierPathWithRoundedRect:self.bounds cornerRadius:self.cornerRadius].CGPath;
    _border.frame = self.bounds;
}

@end

次に、それをxib / storyboardに設定します。

自動レイアウトで動作するカスタムクラスのSwiftソリューション

@Iain Smithからカスタマイズ

class DashedBorderView: UIView {

    @IBInspectable var cornerRadius: CGFloat = 4
    @IBInspectable var borderColor: UIColor = UIColor.black
    @IBInspectable var dashPaintedSize: Int = 2
    @IBInspectable var dashUnpaintedSize: Int = 2

    let dashedBorder = CAShapeLayer()

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

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

    private func commonInit() {
        //custom initialization
        self.layer.addSublayer(dashedBorder)
        applyDashBorder()
    }

    override func layoutSublayers(of layer: CALayer) {
        super.layoutSublayers(of: layer)
        applyDashBorder()
    }

    func applyDashBorder() {
        dashedBorder.strokeColor = borderColor.cgColor
        dashedBorder.lineDashPattern = [NSNumber(value: dashPaintedSize), NSNumber(value: dashUnpaintedSize)]
        dashedBorder.fillColor = nil
        dashedBorder.cornerRadius = cornerRadius
        dashedBorder.path = UIBezierPath(rect: self.bounds).cgPath
        dashedBorder.frame = self.bounds
    }
}

次のようなIBDesignableクラスを作成するだけです。

import UIKit

@IBDesignable
class BorderedView: UIView {

    @IBInspectable var cornerRadius: CGFloat = 0

    @IBInspectable var borderWidth: CGFloat = 0

    @IBInspectable var borderColor: UIColor = UIColor.clear

    override func draw(_ rect: CGRect) {
        let path = UIBezierPath(roundedRect: rect, cornerRadius: cornerRadius)
        path.lineWidth = borderWidth

        borderColor.setStroke()

        let dashPattern : [CGFloat] = [10, 4]
        path.setLineDash(dashPattern, count: 2, phase: 0)
        path.stroke()
    }

}

次に、XcodeのBorderedViewでビューをサブクラス化します。このようにして、インターフェースビルダーからボーダーの色とボーダーの幅を非常に簡単に設定できます！

extension UIView{
func addDashedLineBorder() {
    let color = UIColor.black.cgColor

    let shapeLayer:CAShapeLayer = CAShapeLayer()
    let frameSize = (self.frame.size)
    let shapeRect = CGRect(x: 0, y: 0, width: self.frame.width, height: self.frame.height)

    shapeLayer.bounds = shapeRect
    shapeLayer.position = CGPoint(x: frameSize.width/2, y: frameSize.height/2)
    shapeLayer.fillColor = UIColor.clear.cgColor
    shapeLayer.strokeColor = color
    shapeLayer.lineWidth = 1
    shapeLayer.lineJoin = kCALineJoinRound
    shapeLayer.lineDashPattern = [2,2]
    shapeLayer.path = UIBezierPath(rect: shapeRect).cgPath

    self.layer.addSublayer(shapeLayer)
}

この関数をviewdidLoad（）で遅延して呼び出します。

DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) { 
            // Your code with delay
            self.YourView.addDashedBorder()
        }

•Swift 5

•自動レイアウトで機能

•コーナー半径に対応

import UIKit

    class DashedBorderView: UIView {

    private let dashedLineColor = UIColor.black.cgColor
    private let dashedLinePattern: [NSNumber] = [6, 3]
    private let dashedLineWidth: CGFloat = 4

    private let borderLayer = CAShapeLayer()

    init() {
        super.init(frame: CGRect.zero)

        borderLayer.strokeColor = dashedLineColor
        borderLayer.lineDashPattern = dashedLinePattern
        borderLayer.backgroundColor = UIColor.clear.cgColor
        borderLayer.fillColor = UIColor.clear.cgColor
        borderLayer.lineWidth = dashedLineWidth
        layer.addSublayer(borderLayer)
    }

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

    override func draw(_ rect: CGRect) {
        borderLayer.frame = bounds
        borderLayer.path = UIBezierPath(roundedRect: rect, cornerRadius: layer.cornerRadius).cgPath
    }
}

Swift 4では、次の関数を使用してUIView拡張機能を作成しました。

func borderDash(withRadius cornerRadius: Float, borderWidth: Float, borderColor: UIColor, dashSize: Int) {
    let currentFrame = self.bounds
    let shapeLayer = CAShapeLayer()
    let path = CGMutablePath()
    let radius = CGFloat(cornerRadius)

    // Points - Eight points that define the round border. Each border is defined by two points.
    let topLeftPoint = CGPoint(x: radius, y: 0)
    let topRightPoint = CGPoint(x: currentFrame.size.width - radius, y: 0)
    let middleRightTopPoint = CGPoint(x: currentFrame.size.width, y: radius)
    let middleRightBottomPoint = CGPoint(x: currentFrame.size.width, y: currentFrame.size.height - radius)
    let bottomRightPoint = CGPoint(x: currentFrame.size.width - radius, y: currentFrame.size.height)
    let bottomLeftPoint = CGPoint(x: radius, y: currentFrame.size.height)
    let middleLeftBottomPoint = CGPoint(x: 0, y: currentFrame.size.height - radius)
    let middleLeftTopPoint = CGPoint(x: 0, y: radius)

    // Points - Four points that are the center of the corners borders.
    let cornerTopRightCenter = CGPoint(x: currentFrame.size.width - radius, y: radius)
    let cornerBottomRightCenter = CGPoint(x: currentFrame.size.width - radius, y: currentFrame.size.height - radius)
    let cornerBottomLeftCenter = CGPoint(x: radius, y: currentFrame.size.height - radius)
    let cornerTopLeftCenter = CGPoint(x: radius, y: radius)

    // Angles - The corner radius angles.
    let topRightStartAngle = CGFloat(Double.pi * 3 / 2)
    let topRightEndAngle = CGFloat(0)
    let bottomRightStartAngle = CGFloat(0)
    let bottmRightEndAngle = CGFloat(Double.pi / 2)
    let bottomLeftStartAngle = CGFloat(Double.pi / 2)
    let bottomLeftEndAngle = CGFloat(Double.pi)
    let topLeftStartAngle = CGFloat(Double.pi)
    let topLeftEndAngle = CGFloat(Double.pi * 3 / 2)

    // Drawing a border around a view.
    path.move(to: topLeftPoint)
    path.addLine(to: topRightPoint)
    path.addArc(center: cornerTopRightCenter,
                radius: radius,
                startAngle: topRightStartAngle,
                endAngle: topRightEndAngle,
                clockwise: false)
    path.addLine(to: middleRightBottomPoint)
    path.addArc(center: cornerBottomRightCenter,
                radius: radius,
                startAngle: bottomRightStartAngle,
                endAngle: bottmRightEndAngle,
                clockwise: false)
    path.addLine(to: bottomLeftPoint)
    path.addArc(center: cornerBottomLeftCenter,
                radius: radius,
                startAngle: bottomLeftStartAngle,
                endAngle: bottomLeftEndAngle,
                clockwise: false)
    path.addLine(to: middleLeftTopPoint)
    path.addArc(center: cornerTopLeftCenter,
                radius: radius,
                startAngle: topLeftStartAngle,
                endAngle: topLeftEndAngle,
                clockwise: false)

    // Path is set as the shapeLayer object's path.
    shapeLayer.path = path;
    shapeLayer.backgroundColor = UIColor.clear.cgColor
    shapeLayer.frame = currentFrame
    shapeLayer.masksToBounds = false
    shapeLayer.setValue(0, forKey: "isCircle")
    shapeLayer.fillColor = UIColor.clear.cgColor
    shapeLayer.strokeColor = borderColor.cgColor
    shapeLayer.lineWidth = CGFloat(borderWidth)
    shapeLayer.lineDashPattern = [NSNumber(value: dashSize), NSNumber(value: dashSize)]
    shapeLayer.lineCap = kCALineCapRound

    self.layer.addSublayer(shapeLayer)
    self.layer.cornerRadius = radius;
}

これをcornerRadiusで機能させたい場合は、これを試してください

tagView.clipsToBounds = YES;
tagView.layer.cornerRadius = 20.0f;
tagView.backgroundColor = [UIColor groupTableViewBackgroundColor];

CAShapeLayer *yourViewBorder = [CAShapeLayer layer];
yourViewBorder.strokeColor = [UIColor blackColor].CGColor;
yourViewBorder.fillColor = nil;
yourViewBorder.lineDashPattern = @[@2, @2];
yourViewBorder.frame = tagView.bounds;

// Create the path for to make circle
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:tagView.bounds
                                               byRoundingCorners:UIRectCornerAllCorners
                                                     cornerRadii:CGSizeMake(20, 20)];


yourViewBorder.path = maskPath.CGPath;

[tagView.layer addSublayer:yourViewBorder];

Swift 5+

import UIKit

class DashedBorderView: UIView {

    private let borderLayer = CAShapeLayer()

    init(color: UIColor, width: CGFloat = 1) {
        super.init(frame: CGRect.zero)

        let pattern: [NSNumber] = [NSNumber(value: Float(5 * width)), NSNumber(value: Float(3 * width))]

        borderLayer.backgroundColor = nil
        borderLayer.fillColor = nil
        borderLayer.lineDashPattern = pattern
        borderLayer.lineWidth = width
        borderLayer.strokeColor = color.cgColor

        layer.addSublayer(borderLayer)
    }

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

    override func draw(_ rect: CGRect) {
        borderLayer.frame = bounds
        borderLayer.path = UIBezierPath(roundedRect: rect, cornerRadius: layer.cornerRadius).cgPath
    }
}

使い方：

// f.e. inside UIViewController

let viewWithDashedBorder = DashedBorderView(color: .red, width: 2)
view.addSubview(viewWithDashedBorder)