How to add only a TOP border on a UIButton?

Question

I know how to add border to a button in iOS 7, with the following code :

[[myButton layer] setBorderColor:[[[UIColor grayColor] colorWithAlphaComponent:0.5]          


        

Answer 1

In Swift add an extension for UIView class like this:

**Swift 3 ***

extension UIView {
    func addTopBorderWithColor(color: UIColor, width: CGFloat) {
        let border = CALayer()
        border.backgroundColor = color.cgColor
        border.frame = CGRect(x:0,y: 0, width:self.frame.size.width, height:width)
        self.layer.addSublayer(border)
    }

    func addRightBorderWithColor(color: UIColor, width: CGFloat) {
        let border = CALayer()
        border.backgroundColor = color.cgColor
        border.frame = CGRect(x: self.frame.size.width - width,y: 0, width:width, height:self.frame.size.height)
        self.layer.addSublayer(border)
    }

    func addBottomBorderWithColor(color: UIColor, width: CGFloat) {
        let border = CALayer()
        border.backgroundColor = color.cgColor
        border.frame = CGRect(x:0, y:self.frame.size.height - width, width:self.frame.size.width, height:width)
        self.layer.addSublayer(border)
    }

    func addLeftBorderWithColor(color: UIColor, width: CGFloat) {
        let border = CALayer()
        border.backgroundColor = color.cgColor
        border.frame = CGRect(x:0, y:0, width:width, height:self.frame.size.height)
        self.layer.addSublayer(border)
    }
}

I got this extension from this link:UIView bottom border?

Then call the function like this

var innerView : UIView?
let borderWidth: CGFloat = 1.0
let borderColor : UIColor =  UIColor.redColor()
innerView!.addTopBorderWithColor(borderColor, width: borderWidth)

For adaptive layout use this one

Swift 3

extension UIView {

    func addTopBorder(_ color: UIColor, height: CGFloat) {
        let border = UIView()
        border.backgroundColor = color
        border.translatesAutoresizingMaskIntoConstraints = false
        self.addSubview(border)
        border.addConstraint(NSLayoutConstraint(item: border,
            attribute: NSLayoutAttribute.height,
            relatedBy: NSLayoutRelation.equal,
            toItem: nil,
            attribute: NSLayoutAttribute.height,
            multiplier: 1, constant: height))
        self.addConstraint(NSLayoutConstraint(item: border,
            attribute: NSLayoutAttribute.top,
            relatedBy: NSLayoutRelation.equal,
            toItem: self,
            attribute: NSLayoutAttribute.top,
            multiplier: 1, constant: 0))
        self.addConstraint(NSLayoutConstraint(item: border,
            attribute: NSLayoutAttribute.leading,
            relatedBy: NSLayoutRelation.equal,
            toItem: self,
            attribute: NSLayoutAttribute.leading,
            multiplier: 1, constant: 0))
        self.addConstraint(NSLayoutConstraint(item: border,
            attribute: NSLayoutAttribute.trailing,
            relatedBy: NSLayoutRelation.equal,
            toItem: self,
            attribute: NSLayoutAttribute.trailing,
            multiplier: 1, constant: 0))
    }

    func addBottomBorder(_ color: UIColor, height: CGFloat) {
        let border = UIView()
        border.backgroundColor = color
        border.translatesAutoresizingMaskIntoConstraints = false
        self.addSubview(border)
        border.addConstraint(NSLayoutConstraint(item: border,
            attribute: NSLayoutAttribute.height,
            relatedBy: NSLayoutRelation.equal,
            toItem: nil,
            attribute: NSLayoutAttribute.height,
            multiplier: 1, constant: height))
        self.addConstraint(NSLayoutConstraint(item: border,
            attribute: NSLayoutAttribute.bottom,
            relatedBy: NSLayoutRelation.equal,
            toItem: self,
            attribute: NSLayoutAttribute.bottom,
            multiplier: 1, constant: 0))
        self.addConstraint(NSLayoutConstraint(item: border,
            attribute: NSLayoutAttribute.leading,
            relatedBy: NSLayoutRelation.equal,
            toItem: self,
            attribute: NSLayoutAttribute.leading,
            multiplier: 1, constant: 0))
        self.addConstraint(NSLayoutConstraint(item: border,
            attribute: NSLayoutAttribute.trailing,
            relatedBy: NSLayoutRelation.equal,
            toItem: self,
            attribute: NSLayoutAttribute.trailing,
            multiplier: 1, constant: 0))
    }

    func addLeftBorder(_ color: UIColor, width: CGFloat) {
        let border = UIView()
        border.backgroundColor = color
        border.translatesAutoresizingMaskIntoConstraints = false
        self.addSubview(border)
        border.addConstraint(NSLayoutConstraint(item: border,
            attribute: NSLayoutAttribute.width,
            relatedBy: NSLayoutRelation.equal,
            toItem: nil,
            attribute: NSLayoutAttribute.width,
            multiplier: 1, constant: width))
        self.addConstraint(NSLayoutConstraint(item: border,
            attribute: NSLayoutAttribute.leading,
            relatedBy: NSLayoutRelation.equal,
            toItem: self,
            attribute: NSLayoutAttribute.leading,
            multiplier: 1, constant: 0))
        self.addConstraint(NSLayoutConstraint(item: border,
            attribute: NSLayoutAttribute.bottom,
            relatedBy: NSLayoutRelation.equal,
            toItem: self,
            attribute: NSLayoutAttribute.bottom,
            multiplier: 1, constant: 0))
        self.addConstraint(NSLayoutConstraint(item: border,
            attribute: NSLayoutAttribute.top,
            relatedBy: NSLayoutRelation.equal,
            toItem: self,
            attribute: NSLayoutAttribute.top,
            multiplier: 1, constant: 0))
    }

    func addRightBorder(_ color: UIColor, width: CGFloat) {
        let border = UIView()
        border.backgroundColor = color
        border.translatesAutoresizingMaskIntoConstraints = false
        self.addSubview(border)
        border.addConstraint(NSLayoutConstraint(item: border,
            attribute: NSLayoutAttribute.width,
            relatedBy: NSLayoutRelation.equal,
            toItem: nil,
            attribute: NSLayoutAttribute.width,
            multiplier: 1, constant: width))
        self.addConstraint(NSLayoutConstraint(item: border,
            attribute: NSLayoutAttribute.trailing,
            relatedBy: NSLayoutRelation.equal,
            toItem: self,
            attribute: NSLayoutAttribute.trailing,
            multiplier: 1, constant: 0))
        self.addConstraint(NSLayoutConstraint(item: border,
            attribute: NSLayoutAttribute.bottom,
            relatedBy: NSLayoutRelation.equal,
            toItem: self,
            attribute: NSLayoutAttribute.bottom,
            multiplier: 1, constant: 0))
        self.addConstraint(NSLayoutConstraint(item: border,
            attribute: NSLayoutAttribute.top,
            relatedBy: NSLayoutRelation.equal,
            toItem: self,
            attribute: NSLayoutAttribute.top,
            multiplier: 1, constant: 0))
    }
}

Usage:

button!.addTopBorder(UIColor(red: 247.0/255.0, green: 147.0/255.0, blue: 29.0/255.0, alpha: 0.5), height: borderWidth)