UIView with a Dashed line

Check UIBezierPath setLineDash:count:phase: method:

- (void)setLineDash:(const CGFloat *)pattern count:(NSInteger)count phase:(CGFloat)phase` method. 

This allows you to draw dashed lines.

1. First add a CAShapeLayer. Add it as sublayer to your UIView. It has a path property.
2. Now make an object of UIBezierPath. Draw the line using setLineDash.

For example:

 UIBezierPath *path = [UIBezierPath bezierPath];
 //draw a line
 [path moveToPoint:yourStartPoint]; //add yourStartPoint here
 [path addLineToPoint:yourEndPoint];// add yourEndPoint here
 [path stroke];

 CGFloat dashPattern[] = {2.0f,6.0f,4.0f,2.0f}; //make your pattern here
 [path setLineDash:dashPattern count:4 phase:3];

 UIColor *fill = [UIColor blueColor];
 shapelayer.strokeStart = 0.0;
 shapelayer.strokeColor = fill.CGColor;
 shapelayer.lineWidth = 5.0;
 shapelayer.lineJoin = kCALineJoinMiter;
 shapelayer.lineDashPattern = [NSArray arrayWithObjects:[NSNumber numberWithInt:10],[NSNumber numberWithInt:7], nil];
 shapelayer.lineDashPhase = 3.0f;
 shapelayer.path = path.CGPath;

Note: This answer provides a hint so you can improvise accordingly to your requirement(s).

Dash Line in Swift4 • Xcode 9

Crate a CAShapeLayer & use lineDashPattern

extension UIView {

    func addDashedBorder() {
        //Create a CAShapeLayer
        let shapeLayer = CAShapeLayer()
        shapeLayer.strokeColor = UIColor.red.cgColor
        shapeLayer.lineWidth = 2
        // passing an array with the values [2,3] sets a dash pattern that alternates between a 2-user-space-unit-long painted segment and a 3-user-space-unit-long unpainted segment
        shapeLayer.lineDashPattern = [2,3]

        let path = CGMutablePath()
        path.addLines(between: [CGPoint(x: 0, y: 0),
                                CGPoint(x: self.frame.width, y: 0)])
        shapeLayer.path = path
        layer.addSublayer(shapeLayer)
    }
}

Usage:

dashView.addDashedBorder()

Output: