Dashed line border around UIView

Question

How do I add dashed line border around UIView.

Something Like this

Answer 1

Swift solution with custom class worked with autolayout

customized from @Iain Smith

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
    }
}

Answer 2

For this you need add CAShapeLayer for that particular object

 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;

Answer 3

In swift 4 I created an UIView extension with the following function:

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;
}

Answer 4

Use CGContextSetLineDash() method.

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);

I think it will be helpful to you.

Answer 5

I ended up creating a IB Designable using some of @Chris implementation:

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

then just set it up in the xib/storyboard:

Answer 6

For those of you working in Swift, this class extension on UIView makes it easy. This was based on sunshineDev's answer.

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 = kCALineJoinRound
    shapeLayer.lineDashPattern = [6,3]
    shapeLayer.path = UIBezierPath(roundedRect: shapeRect, cornerRadius: 5).cgPath

    self.layer.addSublayer(shapeLayer)
    }
}

To use it:

anyView.addDashedBorder()