How to add a border just on the top side of a UIView

Question

My question is on the title.

I don't know how to add a border in a specific side, top or bottom, any side... layer.border draws the border for the whole view...

Answer 1

I consider subclassing UIView and overriding drawRect overkill here. Why not add an extension on UIView and add border subviews?

@discardableResult
func addBorders(edges: UIRectEdge,
                color: UIColor,
                inset: CGFloat = 0.0,
                thickness: CGFloat = 1.0) -> [UIView] {

    var borders = [UIView]()

    @discardableResult
    func addBorder(formats: String...) -> UIView {
        let border = UIView(frame: .zero)
        border.backgroundColor = color
        border.translatesAutoresizingMaskIntoConstraints = false
        addSubview(border)
        addConstraints(formats.flatMap {
            NSLayoutConstraint.constraints(withVisualFormat: $0,
                                           options: [],
                                           metrics: ["inset": inset, "thickness": thickness],
                                           views: ["border": border]) })
        borders.append(border)
        return border
    }


    if edges.contains(.top) || edges.contains(.all) {
        addBorder(formats: "V:|-0-[border(==thickness)]", "H:|-inset-[border]-inset-|")
    }

    if edges.contains(.bottom) || edges.contains(.all) {
        addBorder(formats: "V:[border(==thickness)]-0-|", "H:|-inset-[border]-inset-|")
    }

    if edges.contains(.left) || edges.contains(.all) {
        addBorder(formats: "V:|-inset-[border]-inset-|", "H:|-0-[border(==thickness)]")
    }

    if edges.contains(.right) || edges.contains(.all) {
        addBorder(formats: "V:|-inset-[border]-inset-|", "H:[border(==thickness)]-0-|")
    }

    return borders
}

    // Usage:         
    view.addBorder(edges: [.all]) // All with default arguments 
    view.addBorder(edges: [.top], color: .green) // Just Top, green, default thickness
    view.addBorder(edges: [.left, .right, .bottom], color: .red, thickness: 3) // All except Top, red, thickness 3

With this code you're not tied to your subclass too, you can apply it to anything and everything that inherits from UIView - reusable in your project, and any others. Pass in other arguments to your methods to define other colours and widths. Many options.

Answer 2

Added capability for rounded corners to Adam Waite's original post, and the multiple edits

Important!: Don't forgot to add 'label.layoutIfNeeded()' right before calling 'addborder' as previously commented

Note: I've only tested this on UILabels.

extension CALayer {
    
    enum BorderSide {
        case top
        case right
        case bottom
        case left
        case notRight
        case notLeft
        case topAndBottom
        case all
    }
    
    enum Corner {
        case topLeft
        case topRight
        case bottomLeft
        case bottomRight
    }
    
    func addBorder(side: BorderSide, thickness: CGFloat, color: CGColor, maskedCorners: CACornerMask? = nil) {
        var topWidth = frame.size.width; var bottomWidth = topWidth
        var leftHeight = frame.size.height; var rightHeight = leftHeight
        
        var topXOffset: CGFloat = 0; var bottomXOffset: CGFloat = 0
        var leftYOffset: CGFloat = 0; var rightYOffset: CGFloat = 0
        
        // Draw the corners and set side offsets
        switch maskedCorners {
        case [.layerMinXMinYCorner, .layerMaxXMinYCorner]: // Top only
            addCorner(.topLeft, thickness: thickness, color: color)
            addCorner(.topRight, thickness: thickness, color: color)
            topWidth -= cornerRadius*2
            leftHeight -= cornerRadius; rightHeight -= cornerRadius
            topXOffset = cornerRadius; leftYOffset = cornerRadius; rightYOffset = cornerRadius
            
        case [.layerMinXMaxYCorner, .layerMaxXMaxYCorner]: // Bottom only
            addCorner(.bottomLeft, thickness: thickness, color: color)
            addCorner(.bottomRight, thickness: thickness, color: color)
            bottomWidth -= cornerRadius*2
            leftHeight -= cornerRadius; rightHeight -= cornerRadius
            bottomXOffset = cornerRadius
            
        case [.layerMinXMinYCorner, .layerMinXMaxYCorner]: // Left only
            addCorner(.topLeft, thickness: thickness, color: color)
            addCorner(.bottomLeft, thickness: thickness, color: color)
            topWidth -= cornerRadius; bottomWidth -= cornerRadius
            leftHeight -= cornerRadius*2
            leftYOffset = cornerRadius; topXOffset = cornerRadius; bottomXOffset = cornerRadius;
            
        case [.layerMaxXMinYCorner, .layerMaxXMaxYCorner]: // Right only
            addCorner(.topRight, thickness: thickness, color: color)
            addCorner(.bottomRight, thickness: thickness, color: color)
            topWidth -= cornerRadius; bottomWidth -= cornerRadius
            rightHeight -= cornerRadius*2
            rightYOffset = cornerRadius
            
        case [.layerMaxXMinYCorner, .layerMaxXMaxYCorner,  // All
              .layerMinXMaxYCorner, .layerMinXMinYCorner]:
            addCorner(.topLeft, thickness: thickness, color: color)
            addCorner(.topRight, thickness: thickness, color: color)
            addCorner(.bottomLeft, thickness: thickness, color: color)
            addCorner(.bottomRight, thickness: thickness, color: color)
            topWidth -= cornerRadius*2; bottomWidth -= cornerRadius*2
            topXOffset = cornerRadius; bottomXOffset = cornerRadius
            leftHeight -= cornerRadius*2; rightHeight -= cornerRadius*2
            leftYOffset = cornerRadius; rightYOffset = cornerRadius
            
        default: break
        }
        
        // Draw the sides
        switch side {
        case .top:
            addLine(x: topXOffset, y: 0, width: topWidth, height: thickness, color: color)
            
        case .right:
            addLine(x: frame.size.width - thickness, y: rightYOffset, width: thickness, height: rightHeight, color: color)
            
        case .bottom:
            addLine(x: bottomXOffset, y: frame.size.height - thickness, width: bottomWidth, height: thickness, color: color)
            
        case .left:
            addLine(x: 0, y: leftYOffset, width: thickness, height: leftHeight, color: color)

        // Multiple Sides
        case .notRight:
            addLine(x: topXOffset, y: 0, width: topWidth, height: thickness, color: color)
            addLine(x: 0, y: leftYOffset, width: thickness, height: leftHeight, color: color)
            addLine(x: bottomXOffset, y: frame.size.height - thickness, width: bottomWidth, height: thickness, color: color)

        case .notLeft:
            addLine(x: topXOffset, y: 0, width: topWidth, height: thickness, color: color)
            addLine(x: frame.size.width - thickness, y: rightYOffset, width: thickness, height: rightHeight, color: color)
            addLine(x: bottomXOffset, y: frame.size.height - thickness, width: bottomWidth, height: thickness, color: color)

        case .topAndBottom:
            addLine(x: topXOffset, y: 0, width: topWidth, height: thickness, color: color)
            addLine(x: bottomXOffset, y: frame.size.height - thickness, width: bottomWidth, height: thickness, color: color)

        case .all:
            addLine(x: topXOffset, y: 0, width: topWidth, height: thickness, color: color)
            addLine(x: frame.size.width - thickness, y: rightYOffset, width: thickness, height: rightHeight, color: color)
            addLine(x: bottomXOffset, y: frame.size.height - thickness, width: bottomWidth, height: thickness, color: color)
            addLine(x: 0, y: leftYOffset, width: thickness, height: leftHeight, color: color)
        }
    }
    
    private func addLine(x: CGFloat, y: CGFloat, width: CGFloat, height: CGFloat, color: CGColor) {
        let border = CALayer()
        border.frame = CGRect(x: x, y: y, width: width, height: height)
        border.backgroundColor = color
        addSublayer(border)
    }
    
    private func addCorner(_ corner: Corner, thickness: CGFloat, color: CGColor) {
        // Set default to top left
        let width = frame.size.width; let height = frame.size.height
        var x = cornerRadius
        var y = cornerRadius
        var startAngle: CGFloat = .pi; var endAngle: CGFloat = .pi*3/2
        
        switch corner {
        case .bottomLeft:
            y = height - cornerRadius 
            startAngle = .pi/2; endAngle = .pi
            
        case .bottomRight:
            x = width - cornerRadius
            y = height - cornerRadius
            startAngle = 0; endAngle = .pi/2
            
        case .topRight:
            x = width - cornerRadius
            startAngle = .pi*3/2; endAngle = 0
            
        default: break
        }
        
        let cornerPath = UIBezierPath(arcCenter: CGPoint(x: x, y: y),
                                      radius: cornerRadius - thickness,
                                      startAngle: startAngle,
                                      endAngle: endAngle,
                                      clockwise: true)

        let cornerShape = CAShapeLayer()
        cornerShape.path = cornerPath.cgPath
        cornerShape.lineWidth = thickness
        cornerShape.strokeColor = color
        cornerShape.fillColor = nil
        addSublayer(cornerShape)
    }
}

Answer 3

The best way for me is a category on UIView, but adding views instead of CALayers, so we can take advantage of AutoresizingMasks to make sure borders resize along with the superview.

Objective C

- (void)addTopBorderWithColor:(UIColor *)color andWidth:(CGFloat) borderWidth {
    UIView *border = [UIView new];
    border.backgroundColor = color;
    [border setAutoresizingMask:UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleBottomMargin];
    border.frame = CGRectMake(0, 0, self.frame.size.width, borderWidth);
    [self addSubview:border];
}

- (void)addBottomBorderWithColor:(UIColor *)color andWidth:(CGFloat) borderWidth {
    UIView *border = [UIView new];
    border.backgroundColor = color;
    [border setAutoresizingMask:UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleTopMargin];
    border.frame = CGRectMake(0, self.frame.size.height - borderWidth, self.frame.size.width, borderWidth);
    [self addSubview:border];
}

- (void)addLeftBorderWithColor:(UIColor *)color andWidth:(CGFloat) borderWidth {
    UIView *border = [UIView new];
    border.backgroundColor = color;
    border.frame = CGRectMake(0, 0, borderWidth, self.frame.size.height);
    [border setAutoresizingMask:UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleRightMargin];
    [self addSubview:border];
}

- (void)addRightBorderWithColor:(UIColor *)color andWidth:(CGFloat) borderWidth {
    UIView *border = [UIView new];
    border.backgroundColor = color;
    [border setAutoresizingMask:UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleLeftMargin];
    border.frame = CGRectMake(self.frame.size.width - borderWidth, 0, borderWidth, self.frame.size.height);
    [self addSubview:border];
}

Swift 5

func addTopBorder(with color: UIColor?, andWidth borderWidth: CGFloat) {
    let border = UIView()
    border.backgroundColor = color
    border.autoresizingMask = [.flexibleWidth, .flexibleBottomMargin]
    border.frame = CGRect(x: 0, y: 0, width: frame.size.width, height: borderWidth)
    addSubview(border)
}

func addBottomBorder(with color: UIColor?, andWidth borderWidth: CGFloat) {
    let border = UIView()
    border.backgroundColor = color
    border.autoresizingMask = [.flexibleWidth, .flexibleTopMargin]
    border.frame = CGRect(x: 0, y: frame.size.height - borderWidth, width: frame.size.width, height: borderWidth)
    addSubview(border)
}

func addLeftBorder(with color: UIColor?, andWidth borderWidth: CGFloat) {
    let border = UIView()
    border.backgroundColor = color
    border.frame = CGRect(x: 0, y: 0, width: borderWidth, height: frame.size.height)
    border.autoresizingMask = [.flexibleHeight, .flexibleRightMargin]
    addSubview(border)
}

func addRightBorder(with color: UIColor?, andWidth borderWidth: CGFloat) {
    let border = UIView()
    border.backgroundColor = color
    border.autoresizingMask = [.flexibleHeight, .flexibleLeftMargin]
    border.frame = CGRect(x: frame.size.width - borderWidth, y: 0, width: borderWidth, height: frame.size.height)
    addSubview(border)
}

Answer 4

Swift 3.0

Swift 4.1

extension CALayer {

  func addBorder(edge: UIRectEdge, color: UIColor, thickness: CGFloat) {

    let border = CALayer()

    switch edge {
    case UIRectEdge.top:
        border.frame = CGRect(x: 0, y: 0, width: frame.width, height: thickness)

    case UIRectEdge.bottom:
        border.frame = CGRect(x:0, y: frame.height - thickness, width: frame.width, height:thickness)

    case UIRectEdge.left:
        border.frame = CGRect(x:0, y:0, width: thickness, height: frame.height)

    case UIRectEdge.right:
        border.frame = CGRect(x: frame.width - thickness, y: 0, width: thickness, height: frame.height)

    default: do {}
    }

    border.backgroundColor = color.cgColor

    addSublayer(border)
 }
}

Answer 5

Subclass UIView and implement drawRect: in your subclass, eg:

Objective-c

- (void)drawRect:(CGRect)rect {
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextMoveToPoint(context, CGRectGetMinX(rect), CGRectGetMinY(rect));
    CGContextAddLineToPoint(context, CGRectGetMaxX(rect), CGRectGetMinY(rect));
    CGContextSetStrokeColorWithColor(context, [[UIColor redColor] CGColor] );
    CGContextSetLineWidth(context, 2.0);
    CGContextStrokePath(context);
}

Swift 4

override func draw(_ rect: CGRect) {

    let cgContext = UIGraphicsGetCurrentContext()
    cgContext?.move(to: CGPoint(x: rect.minX, y: rect.minY))
    cgContext?.addLine(to: CGPoint(x: rect.maxX, y: rect.minY))
    cgContext?.setStrokeColor(UIColor.red.cgColor)
    cgContext?.setLineWidth(2.0)
    cgContext?.strokePath()
}

This draws a 2 pixel red line as a top border. All of the other variations you mention are left as a trivial exercise for the reader.

Quartz 2D Programming Guide is recommended.

Answer 6

Code for the selected answer, in case anyone wants it.

NOTE: This does not work with autolayout (aka, rotating device to landscape, etc).

First define a thickness:

NSInteger borderThickness = 1;

Then just copy use any or all of these to set the border you want to set.

Top Border

UIView *topBorder = [UIView new];
topBorder.backgroundColor = [UIColor lightGrayColor];
topBorder.frame = CGRectMake(0, 0, myView.frame.size.width, borderThickness);
[myView addSubview:topBorder];

Bottom Border

UIView *bottomBorder = [UIView new];
bottomBorder.backgroundColor = [UIColor lightGrayColor];
bottomBorder.frame = CGRectMake(0, myView.frame.size.height - borderThickness, myView.frame.size.width, borderThickness);
[myView addSubview:bottomBorder];

Left Border

UIView *leftBorder = [UIView new];
leftBorder.backgroundColor = [UIColor lightGrayColor];
leftBorder.frame = CGRectMake(0, 0, borderThickness, myView.frame.size.height);
[myView addSubview:leftBorder];

Right Border

UIView *rightBorder = [UIView new];
rightBorder.backgroundColor = [UIColor lightGrayColor];
rightBorder.frame = CGRectMake(myView.frame.size.width - borderThickness, 0, borderThickness, myView.frame.size.height);
[myView addSubview:rightBorder];

Answer 7

Old question, but the autolayout-solution with runtime border adjustments still missing.

borders(for: [.left, .bottom], width: 2, color: .red)

The following UIView extension will add the border only on the given edges. If you change the edges at runtime, the borders will adjust accordingly.

extension UIView {
    func borders(for edges:[UIRectEdge], width:CGFloat = 1, color: UIColor = .black) {

        if edges.contains(.all) {
            layer.borderWidth = width
            layer.borderColor = color.cgColor
        } else {
            let allSpecificBorders:[UIRectEdge] = [.top, .bottom, .left, .right]

            for edge in allSpecificBorders {
                if let v = viewWithTag(Int(edge.rawValue)) {
                    v.removeFromSuperview()
                }

                if edges.contains(edge) {
                    let v = UIView()
                    v.tag = Int(edge.rawValue)
                    v.backgroundColor = color
                    v.translatesAutoresizingMaskIntoConstraints = false
                    addSubview(v)

                    var horizontalVisualFormat = "H:"
                    var verticalVisualFormat = "V:"

                    switch edge {
                    case UIRectEdge.bottom:
                        horizontalVisualFormat += "|-(0)-[v]-(0)-|"
                        verticalVisualFormat += "[v(\(width))]-(0)-|"
                    case UIRectEdge.top:
                        horizontalVisualFormat += "|-(0)-[v]-(0)-|"
                        verticalVisualFormat += "|-(0)-[v(\(width))]"
                    case UIRectEdge.left:
                        horizontalVisualFormat += "|-(0)-[v(\(width))]"
                        verticalVisualFormat += "|-(0)-[v]-(0)-|"
                    case UIRectEdge.right:
                        horizontalVisualFormat += "[v(\(width))]-(0)-|"
                        verticalVisualFormat += "|-(0)-[v]-(0)-|"
                    default:
                        break
                    }

                    self.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: horizontalVisualFormat, options: .directionLeadingToTrailing, metrics: nil, views: ["v": v]))
                    self.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: verticalVisualFormat, options: .directionLeadingToTrailing, metrics: nil, views: ["v": v]))
                }
            }
        }
    }
}

Answer 8

Swift version:

var myView = UIView(frame: CGRect(x: 100, y: 100, width: 100, height: 100))
myView.backgroundColor = UIColor.yellowColor() 

var border = CALayer()
border.backgroundColor = UIColor.lightGrayColor()
border.frame = CGRect(x: 0, y: 0, width: myView.frame.width, height: 0.5)

myView.layer.addSublayer(border)

Edit: For updated versions check my repo here: https://github.com/goktugyil/EZSwiftExtensions/blob/master/Sources/UIViewExtensions.swift

Look at the addBorder parts

Answer 9

Swift 4.2 and AutoLayout

I went through the offered solutions. Many are based in frames This is a simple extension that works with AutoLayout - use View instead of Layer to make sure we can use AutoLayout - Single subview with 4 constraints

Use as follows:

self.addBorder(.bottom, color: .lightGray, thickness: 0.5)


extension UIView {
    func addBorder(_ edge: UIRectEdge, color: UIColor, thickness: CGFloat) {
        let subview = UIView()
        subview.translatesAutoresizingMaskIntoConstraints = false
        subview.backgroundColor = color
        self.addSubview(subview)
        switch edge {
        case .top, .bottom:
            subview.leftAnchor.constraint(equalTo: self.leftAnchor, constant: 0).isActive = true
            subview.rightAnchor.constraint(equalTo: self.rightAnchor, constant: 0).isActive = true
            subview.heightAnchor.constraint(equalToConstant: thickness).isActive = true
            if edge == .top {
                subview.topAnchor.constraint(equalTo: self.topAnchor, constant: 0).isActive = true
            } else {
                subview.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: 0).isActive = true
            }
        case .left, .right:
            subview.topAnchor.constraint(equalTo: self.topAnchor, constant: 0).isActive = true
            subview.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: 0).isActive = true
            subview.widthAnchor.constraint(equalToConstant: thickness).isActive = true
            if edge == .left {
                subview.leftAnchor.constraint(equalTo: self.leftAnchor, constant: 0).isActive = true
            } else {
                subview.rightAnchor.constraint(equalTo: self.rightAnchor, constant: 0).isActive = true
            }
        default:
            break
        }
    }
}

Answer 10

I took both Adam Waite's and Pauls answers and combined them. I also added the possibility to pipe the selected edges together, so you need to call only one function like so:

[self.view addBordersToEdge:(UIRectEdgeLeft|UIRectEdgeRight)
                  withColor:[UIColor grayColor]
                   andWidth:1.0];

or so:

[self.view addBordersToEdge:(UIRectEdgeAll)
                  withColor:[UIColor grayColor]
                   andWidth:1.0];

What you need to implement is a category on UIView as suggested in other answers with the following implementation:

- (void)addBordersToEdge:(UIRectEdge)edge withColor:(UIColor *)color andWidth:(CGFloat) borderWidth {
    if (edge & UIRectEdgeTop) {
        UIView *border = [UIView new];
        border.backgroundColor = color;
        [border setAutoresizingMask:UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleBottomMargin];
        border.frame = CGRectMake(0, 0, self.frame.size.width, borderWidth);
        [self addSubview:border];
    }

    if (edge & UIRectEdgeLeft) {
        UIView *border = [UIView new];
        border.backgroundColor = color;
        border.frame = CGRectMake(0, 0, borderWidth, self.frame.size.height);
        [border setAutoresizingMask:UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleRightMargin];
        [self addSubview:border];
    }

    if (edge & UIRectEdgeBottom) {
        UIView *border = [UIView new];
        border.backgroundColor = color;
        [border setAutoresizingMask:UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleTopMargin];
        border.frame = CGRectMake(0, self.frame.size.height - borderWidth, self.frame.size.width, borderWidth);
        [self addSubview:border];
    }

    if (edge & UIRectEdgeRight) {
        UIView *border = [UIView new];
        border.backgroundColor = color;
        [border setAutoresizingMask:UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleLeftMargin];
        border.frame = CGRectMake(self.frame.size.width - borderWidth, 0, borderWidth, self.frame.size.height);
        [self addSubview:border];
    }
}

Answer 11

//MARK:- Add LeftBorder For View

(void)prefix_addLeftBorder:(UIView *) viewName
{
    CALayer *leftBorder = [CALayer layer];
    leftBorder.backgroundColor = [UIColor colorWithRed:221/255.0f green:221/255.0f blue:221/255.0f alpha:1.0f].CGColor;
    leftBorder.frame = CGRectMake(0,0,1.0,viewName.frame.size.height);
    [viewName.layer addSublayer:leftBorder];
}

//MARK:- Add RightBorder For View

(void)prefix_addRightBorder:(UIView *) viewName
{
    CALayer *rightBorder = [CALayer layer];
    rightBorder.backgroundColor = [UIColor colorWithRed:221/255.0f green:221/255.0f blue:221/255.0f alpha:1.0f].CGColor;
    rightBorder.frame = CGRectMake(viewName.frame.size.width - 1.0,0,1.0,viewName.frame.size.height);
    [viewName.layer addSublayer:rightBorder];
}

//MARK:- Add Bottom Border For View

(void)prefix_addbottomBorder:(UIView *) viewName
{
    CALayer *bottomBorder = [CALayer layer];
    bottomBorder.backgroundColor = [UIColor colorWithRed:221/255.0f green:221/255.0f blue:221/255.0f alpha:1.0f].CGColor;
    bottomBorder.frame = CGRectMake(0,viewName.frame.size.height - 1.0,viewName.frame.size.width,1.0);
    [viewName.layer addSublayer:bottomBorder];
}

Answer 12

Building off of NSBum's answer, I took a similar approach and created this simple UIView subclass so that it works in Interface Builder and works with constraints: github link
By using CGContextFillRect instead of CGContextStrokePath, I was able to predictably keep the lines completely solid and within the bounds of the view.

Here's my blog post about it: http://natrosoft.com/?p=55

-- Basically just drop in a UIView in Interface Builder and change its class type to NAUIViewWithBorders.
-- Then in your VC's viewDidLoad do something like:

/* For a top border only ———————————————- */
self.myBorderView.borderColorTop = [UIColor redColor];
self.myBorderView..borderWidthsAll = 1.0f;

/* For borders with different colors and widths ————————— */
self.myBorderView.borderWidths = UIEdgeInsetsMake(2.0, 4.0, 6.0, 8.0);
self.myBorderView.borderColorTop = [UIColor blueColor];
self.myBorderView.borderColorRight = [UIColor redColor];
self.myBorderView.borderColorBottom = [UIColor greenColor];
self.myBorderView.borderColorLeft = [UIColor darkGrayColor];

Here's a direct link to the .m file so you can see the implementation. There is a demo project as well. Hope this helps someone :)

Answer 13

I made some changes to Dan's answer so that I could add borders to multiple edges with one command:

infoView.addBorder(toEdges: [.left, .bottom, .right], color: borderColor, thickness: 1)

Here's the full code:

extension UIView {
    func addBorder(toEdges edges: UIRectEdge, color: UIColor, thickness: CGFloat) {

        func addBorder(toEdge edges: UIRectEdge, color: UIColor, thickness: CGFloat) {
            let border = CALayer()
            border.backgroundColor = color.cgColor

            switch edges {
            case .top:
                border.frame = CGRect(x: 0, y: 0, width: frame.width, height: thickness)
            case .bottom:
                border.frame = CGRect(x: 0, y: frame.height - thickness, width: frame.width, height: thickness)
            case .left:
                border.frame = CGRect(x: 0, y: 0, width: thickness, height: frame.height)
            case .right:
                border.frame = CGRect(x: frame.width - thickness, y: 0, width: thickness, height: frame.height)
            default:
                break
            }

            layer.addSublayer(border)
        }

        if edges.contains(.top) || edges.contains(.all) {
            addBorder(toEdge: .top, color: color, thickness: thickness)
        }

        if edges.contains(.bottom) || edges.contains(.all) {
            addBorder(toEdge: .bottom, color: color, thickness: thickness)
        }

        if edges.contains(.left) || edges.contains(.all) {
            addBorder(toEdge: .left, color: color, thickness: thickness)
        }

        if edges.contains(.right) || edges.contains(.all) {
            addBorder(toEdge: .right, color: color, thickness: thickness)
        }
    }
}

Answer 14

Here's a simple solution. Add a label onto your UIView , clear the text on the label and set the label background color to be your border color. Set the origin (x,y) of your label to be the origin (x,y) of your view. and set the width of the label to be the width of your UIView , set the height to be 1 or 2 (for your border height at the top of your UIView ). And that should do the trick.

Answer 15

我对类似问题的回答： https : //stackoverflow.com/a/27141956/435766我个人更喜欢在那个类别上走下去，因为我希望能够在 UIView 的任何子类上使用它。

Answer 16

In case someone will ever need Xamarin version:

public static class UIUtils
{
    public static void AddBorder(this CALayer cALayer, UIRectEdge edge, UIColor color, float thickness)
    {

        var border = new CALayer();
        switch (edge) 
        {
            case UIRectEdge.Top:
                border.Frame = new CGRect(0, 0, cALayer.Frame.Width, height: thickness);
                break;
            case UIRectEdge.Bottom:
                border.Frame = new CGRect(0, cALayer.Frame.Height - thickness, width: cALayer.Frame.Width, height: thickness);
                break;
            case UIRectEdge.Left:
                border.Frame = new CGRect(0, 0, width: thickness, height: cALayer.Frame.Height);
                break;
            case UIRectEdge.Right:
                border.Frame = new CGRect(cALayer.Frame.Width - thickness, y: 0, width: thickness, height: cALayer.Frame.Height);
                break;
            default: break;
        }
        border.BackgroundColor = color.CGColor;
        cALayer.AddSublayer(border);
    }
}

Answer 17

extension UIView {

    func addBorder(edge: UIRectEdge, color: UIColor, borderWidth: CGFloat) {

        let seperator = UIView()
        self.addSubview(seperator)
        seperator.translatesAutoresizingMaskIntoConstraints = false

        seperator.backgroundColor = color

        if edge == .top || edge == .bottom
        {
            seperator.leadingAnchor.constraint(equalTo: self.leadingAnchor, constant: 0).isActive = true
            seperator.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: 0).isActive = true
            seperator.heightAnchor.constraint(equalToConstant: borderWidth).isActive = true

            if edge == .top
            {
                seperator.topAnchor.constraint(equalTo: self.topAnchor, constant: 0).isActive = true
            }
            else
            {
                seperator.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: 0).isActive = true
            }
        }
        else if edge == .left || edge == .right
        {
            seperator.topAnchor.constraint(equalTo: self.topAnchor, constant: 0).isActive = true
            seperator.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: 0).isActive = true
            seperator.widthAnchor.constraint(equalToConstant: borderWidth).isActive = true

            if edge == .left
            {
                seperator.leadingAnchor.constraint(equalTo: self.leadingAnchor, constant: 0).isActive = true
            }
            else
            {
                seperator.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: 0).isActive = true
            }
        }
    }

}

Answer 18

Swift 3 version

extension UIView {
    enum ViewSide {
        case Top, Bottom, Left, Right
    }

    func addBorder(toSide side: ViewSide, withColor color: UIColor, andThickness thickness: CGFloat) {

        let border = CALayer()
        border.backgroundColor = color.cgColor

        switch side {
        case .Top:
            border.frame = CGRect(x: 0, y: 0, width: frame.size.width, height: thickness)
        case .Bottom:
            border.frame = CGRect(x: 0, y: frame.size.height - thickness, width: frame.size.width, height: thickness)
        case .Left:
            border.frame = CGRect(x: 0, y: 0, width: thickness, height: frame.size.height)
        case .Right:
            border.frame = CGRect(x: frame.size.width - thickness, y: 0, width: thickness, height: frame.size.height)
        }

        layer.addSublayer(border)
    }
}

In order to set corresponding border you should override viewDidLayoutSubviews() method:

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()
    yourView.addBorder(toSide: UIView.ViewSide.Top, withColor: UIColor.lightGray, andThickness: 1)

Answer 19

如果我从故事板内建筑，我更喜欢添加一个UIView背后我有用UIView ...如果我要创建我的顶部边框UIView ，我只是增加的背景下高度UIView我的边框宽度。 . 任何其他方面都可以这样做:)

Answer 20

Just posting here to help someone looking for adding borders. I have made a few changes in the accepted answer here swift label only border left . Changed width in case UIRectEdge.Top from CGRectGetHeight(self.frame) to CGRectGetWidth(self.frame) and in case UIRectEdge.Bottom from UIScreen.mainScreen().bounds.width to CGRectGetWidth(self.frame) to get borders correctly. Using Swift 2.

Finally the extension is :

extension CALayer {

func addBorder(edge: UIRectEdge, color: UIColor, thickness: CGFloat) {

    let border = CALayer();

    switch edge {
    case UIRectEdge.Top:
        border.frame = CGRectMake(0, 0, CGRectGetWidth(self.frame), thickness); 
        break
    case UIRectEdge.Bottom:
        border.frame = CGRectMake(0, CGRectGetHeight(self.frame) - thickness, CGRectGetWidth(self.frame), thickness)
        break
    case UIRectEdge.Left:
        border.frame = CGRectMake(0, 0, thickness, CGRectGetHeight(self.frame))
        break
    case UIRectEdge.Right:
        border.frame = CGRectMake(CGRectGetWidth(self.frame) - thickness, 0, thickness, CGRectGetHeight(self.frame))
        break
    default:
        break
    }

    border.backgroundColor = color.CGColor;

    self.addSublayer(border)
}

}

Answer 21

Convert DanShev answer to Swift 3

extension CALayer {

func addBorder(edge: UIRectEdge, color: UIColor, thickness: CGFloat) {

    let border = CALayer()

    switch edge {
    case .top:
        border.frame = CGRect(x: 0, y: 0, width: self.frame.width, height: thickness)
        break
    case .bottom:
        border.frame = CGRect(x: 0, y: self.frame.height - thickness, width: self.frame.width, height: thickness)
        break
    case .left:
        border.frame = CGRect(x: 0, y: 0, width: thickness, height: self.frame.height)
        break
    case .right:
        border.frame = CGRect(x: self.frame.width - thickness, y: 0, width: thickness, height: self.frame.height)
        break
    default:
        break
    }

    border.backgroundColor = color.cgColor;

    self.addSublayer(border)
}
}

Answer 22

For Xamarin in C# I just create the border inline when adding the sub layer

  View.Layer.AddSublayer(new CALayer()
    {
        BackgroundColor = UIColor.Black.CGColor,
        Frame = new CGRect(0, 0, View.Frame.Width, 0.5f)
    });

You can arrange this (as suggested by others) for bottom, left and right borders.

Answer 23

Here's a Swift 4 version of Pauls's answer

func addTopBorder(color: UIColor, thickness: CGFloat) {
    let border = UIView()
    border.backgroundColor = color
    border.autoresizingMask = [.flexibleWidth, .flexibleBottomMargin]
    border.frame = CGRect(x: 0, y: 0, width: frame.size.width, height: thickness)
    addSubview(border)
}

func addBottomBorder(color: UIColor, thickness: CGFloat) {
    let border = UIView()
    border.backgroundColor = color
    border.autoresizingMask = [.flexibleWidth, .flexibleTopMargin]
    border.frame = CGRect(x: 0, y: frame.size.height - thickness, width: frame.size.width, height: thickness)
    addSubview(border)
}

func addLeftBorder(color: UIColor, thickness: CGFloat) {
    let border = UIView()
    border.backgroundColor = color
    border.autoresizingMask = [.flexibleHeight, .flexibleRightMargin]
    border.frame = CGRect(x: 0, y: 0, width: thickness, height: frame.size.height)
    addSubview(border)
}

func addRightBorder(color: UIColor, thickness: CGFloat) {
    let border = UIView()
    border.backgroundColor = color
    border.autoresizingMask = [.flexibleHeight, .flexibleLeftMargin]
    border.frame = CGRect(x: frame.size.width - thickness, y: 0, width: thickness, height: frame.size.height)
    addSubview(border)
}

Answer 24

Inspired by @Addison I've rewritten the extension without the use of any third party framework, as he used SnapKit and CocoaLumberjack.

As in @Addisons approach I'm also removing previously added borders, so this implementation should play nice with reusable views as table cells and collection cells.

fileprivate class BorderView: UIView {} // dummy class to help us differentiate among border views and other views
                                        // to enabling us to remove existing borders and place new ones

extension UIView {

    func setBorders(toEdges edges: [UIRectEdge], withColor color: UIColor, inset: CGFloat = 0, thickness: CGFloat) {
        // Remove existing edges
        for view in subviews {
            if view is BorderView {
                view.removeFromSuperview()
            }
        }
        // Add new edges
        if edges.contains(.all) {
            addSidedBorder(toEdge: [.left,.right, .top, .bottom], withColor: color, inset: inset, thickness: thickness)
        }
        if edges.contains(.left) {
            addSidedBorder(toEdge: [.left], withColor: color, inset: inset, thickness: thickness)
        }
        if edges.contains(.right) {
            addSidedBorder(toEdge: [.right], withColor: color, inset: inset, thickness: thickness)
        }
        if edges.contains(.top) {
            addSidedBorder(toEdge: [.top], withColor: color, inset: inset, thickness: thickness)
        }
        if edges.contains(.bottom) {
            addSidedBorder(toEdge: [.bottom], withColor: color, inset: inset, thickness: thickness)
        }
    }

    private func addSidedBorder(toEdge edges: [RectangularEdges], withColor color: UIColor, inset: CGFloat = 0, thickness: CGFloat) {
        for edge in edges {
            let border = BorderView(frame: .zero)
            border.backgroundColor = color
            addSubview(border)
            border.translatesAutoresizingMaskIntoConstraints = false
            switch edge {
            case .left:
                NSLayoutConstraint.activate([
                border.leftAnchor.constraint(equalTo: self.leftAnchor, constant: inset),
                    border.topAnchor.constraint(equalTo: self.topAnchor, constant: inset),
                    border.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: -inset),
                    NSLayoutConstraint(item: border, attribute: .width, relatedBy: .equal, toItem: nil, attribute: .width, multiplier: 1, constant: thickness) ])
            case .right:
                NSLayoutConstraint.activate([
                    border.rightAnchor.constraint(equalTo: self.rightAnchor, constant: -inset),
                    border.topAnchor.constraint(equalTo: self.topAnchor, constant: inset),
                    border.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: -inset),
                    NSLayoutConstraint(item: border, attribute: .width, relatedBy: .equal, toItem: nil, attribute: .width, multiplier: 1, constant: thickness) ])
            case .top:
                NSLayoutConstraint.activate([
                    border.leftAnchor.constraint(equalTo: self.leftAnchor, constant: inset),
                    border.rightAnchor.constraint(equalTo: self.rightAnchor, constant: -inset),
                    border.topAnchor.constraint(equalTo: self.topAnchor, constant: inset),
                    NSLayoutConstraint(item: border, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .height, multiplier: 1, constant: thickness) ])
            case .bottom:
                NSLayoutConstraint.activate([
                    border.leftAnchor.constraint(equalTo: self.leftAnchor, constant: inset),
                    border.rightAnchor.constraint(equalTo: self.rightAnchor, constant: -inset),
                    border.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: -inset),
                    NSLayoutConstraint(item: border, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .height, multiplier: 1, constant: thickness) ])
            }
        }
    }

    private enum RectangularEdges {
        case left
        case right
        case top
        case bottom
    }
}

Answer 25

Personally I like the sub-classing of the view + drawRect, but here's just another way of going about it (and it kind of works along the same lines as the accepted answer by @If Pollavith):

Your new border layer can be set up to have whatever dimensions you like. So, like @If Pollavith's answer, you create a layer to be as tall as you want it to be, and as wide as the view you want to have bordered. Use the layer's frame definition to place it where you want it, and then add it as a sub-layer to your view.

For reference, my own requirement was to put a border on the LEFT-HAND side of the view (please don't cut and paste this code and dis' me just 'cos it doesn't put a border at the top of the view -- modifying the code below is simple enough):

    CALayer *leftBorder = [CALayer layer];
leftBorder.borderColor = [UIColor colorWithRed:0.0 green:91.0/255.0 blue:141.0/255.0 alpha:1.0].CGColor;
leftBorder.borderWidth = 1;
leftBorder.frame = CGRectMake(0, 0, 1.0, CGRectGetHeight(self.myTargetView.frame));
[self.myTargetView.layer addSublayer:leftBorder];

I guess the only moderate benefit over this and making a small UIView or UILabel is that the CALayer is supposedly 'lighter-weight', and there's a lot of interesting views (as in opinions) about over-riding drawRect versus using CALayers (like here: iOS: Using UIView's 'drawRect:' vs. its layer's delagate 'drawLayer:inContext:' ).

Animal451

I like the colour blue.

Answer 26

In addition to n8tr can add that there is an availability to set them from storyboard either:
- add two properties like borderColor and borderWidth in .h file;
- then you could add keyPaths right in storyboard, see link to screenshot

Answer 27

You can also check this collection of UIKit and Foundation categories: https://github.com/leszek-s/LSCategories

It allows adding border on one side of UIView with single line of code:

[self.someView lsAddBorderOnEdge:UIRectEdgeTop color:[UIColor blueColor] width:2];

and it properly handles view rotation while most of answers posted here do not handle it well.

Answer 28

Note: most solutions here are not adaptive and will not resize. The solutions that will resize will have a massive impact on your startup time since they use a lot of CPU.

You can use this solution beneath. It works on UIBezierPaths which are lighter than layers, causing quick startup times. It is easy to use, see instructions beneath.

class ResizeBorderView: UIView {
    var color = UIColor.white
    var lineWidth: CGFloat = 1
    var edges = [UIRectEdge](){
        didSet {
            setNeedsDisplay()
        }
    }
    override func draw(_ rect: CGRect) {
        if edges.contains(.top) || edges.contains(.all){
            let path = UIBezierPath()
            path.lineWidth = lineWidth
            color.setStroke()
            UIColor.blue.setFill()
            path.move(to: CGPoint(x: 0, y: 0 + lineWidth / 2))
            path.addLine(to: CGPoint(x: self.bounds.width, y: 0 + lineWidth / 2))
            path.stroke()
        }
        if edges.contains(.bottom) || edges.contains(.all){
            let path = UIBezierPath()
            path.lineWidth = lineWidth
            color.setStroke()
            UIColor.blue.setFill()
            path.move(to: CGPoint(x: 0, y: self.bounds.height - lineWidth / 2))
            path.addLine(to: CGPoint(x: self.bounds.width, y: self.bounds.height - lineWidth / 2))
            path.stroke()
        }
        if edges.contains(.left) || edges.contains(.all){
            let path = UIBezierPath()
            path.lineWidth = lineWidth
            color.setStroke()
            UIColor.blue.setFill()
            path.move(to: CGPoint(x: 0 + lineWidth / 2, y: 0))
            path.addLine(to: CGPoint(x: 0 + lineWidth / 2, y: self.bounds.height))
            path.stroke()
        }
        if edges.contains(.right) || edges.contains(.all){
            let path = UIBezierPath()
            path.lineWidth = lineWidth
            color.setStroke()
            UIColor.blue.setFill()
            path.move(to: CGPoint(x: self.bounds.width - lineWidth / 2, y: 0))
            path.addLine(to: CGPoint(x: self.bounds.width - lineWidth / 2, y: self.bounds.height))
            path.stroke()
        }
    }
}

1. Set your UIView's class to ResizeBorderView
2. Set the color and line width by using yourview.color and yourview.lineWidth in your viewDidAppear method
3. Set the edges, example: yourview.edges = [.right, .left] ([.all]) for all
4. Enjoy quick start and resizing borders

Answer 29

For setting Top Border and Bottom Border for a UIView in Swift.

let topBorder = UIView(frame: CGRect(x: 0, y: 0, width: 10, height: 1))
topBorder.backgroundColor = UIColor.black
myView.addSubview(topBorder)

let bottomBorder = UIView(frame: CGRect(x: 0, y: myView.frame.size.height - 1, width: 10, height: 1))
bottomBorder.backgroundColor = UIColor.black
myView.addSubview(bottomBorder)

Answer 30

In Swift 4 and 3

let borderThickness = 2
let topBorder = UIView()
topBorder.backgroundColor = UIColor.red
topBorder.frame = CGRect(x: 0, y: 0, width: 
                  Int(yourViewFromOutlet.frame.size.width), height: 
                  borderThickness)
yourViewFromOutlet.addSubview(topBorder)

Answer 31

I came up with a solution using Swift 4.1 that uses AutoLayout and UIViews so that it will resize with the view.

It is based off @AdamWaite 's answer but solves the issue for table view cells where the cells are reused. If the previous border is not removed before adding a new one, then the reused cell will contain multiple borders.

This is solved by creating a dummy BorderView class and searching the subview's for the borders and removing them.

This code uses SnapKit for constraints and CocoaLumberjack for debugging. If you are not using these, then it should be fairly straightforward to convert

class BorderView: UIView {
}

extension UIView {
    private func addSidedBorder(toEdge edge: UIRectEdge, withColor color: UIColor, inset: CGFloat, thickness: CGFloat) {
        let border = BorderView(frame: .zero)
        border.backgroundColor = color
        addSubview(border)

        border.snp.makeConstraints { make in
            switch edge {
            case .top:
                make.top.equalToSuperview()
                make.height.equalTo(thickness)
                make.left.right.equalToSuperview().inset(inset)

            case .left:
                make.left.equalToSuperview()
                make.width.equalTo(thickness)
                make.top.bottom.equalToSuperview().inset(inset)

            case .bottom:
                make.bottom.equalToSuperview()
                make.height.equalTo(thickness)
                make.left.right.equalToSuperview().inset(inset)

            case .right:
                make.right.equalToSuperview()
                make.width.equalTo(thickness)
                make.top.bottom.equalToSuperview().inset(inset)

            default:
                DDLogWarn("Invalid sided border given in ExtendedUIView, border not added correctly")
            }
        }
    }

    func addBorder(toEdge edge: UIRectEdge, withColor color: UIColor = .black, inset: CGFloat = 0.0, thickness: CGFloat = 1.0) {
        // Remove existing borders from view and readd them
        for view in subviews {
            if view is BorderView {
                view.removeFromSuperview()
            }
        }

        if edge.contains(.all) {
            addSidedBorder(toEdge: .top, withColor: color, inset: inset, thickness: thickness)
            addSidedBorder(toEdge: .left, withColor: color, inset: inset, thickness: thickness)
            addSidedBorder(toEdge: .bottom, withColor: color, inset: inset, thickness: thickness)
            addSidedBorder(toEdge: .right, withColor: color, inset: inset, thickness: thickness)
        } else {
            if edge.contains(.top) {
                addSidedBorder(toEdge: .top, withColor: color, inset: inset, thickness: thickness)
            }

            if edge.contains(.left) {
                addSidedBorder(toEdge: .left, withColor: color, inset: inset, thickness: thickness)
            }

            if edge.contains(.bottom) {
                addSidedBorder(toEdge: .bottom, withColor: color, inset: inset, thickness: thickness)
            }

            if edge.contains(.right) {
                addSidedBorder(toEdge: .right, withColor: color, inset: inset, thickness: thickness)
            }
        }
    }
}

Add this code and then within a class that subclasses UIView , call:

view.addBorder(toEdge: [.left, .right], withColor: .red, inset: 0.0, thickness: 1.0)

Answer 32

For me works

extension UIView {

    func addBorders(edges: UIRectEdge = .all, color: UIColor = .black, width: CGFloat = 1.0) {

        func createBorder() -> UIView {
            let borderView = UIView(frame: CGRect.zero)
            borderView.translatesAutoresizingMaskIntoConstraints = false
            borderView.backgroundColor = color
            return borderView
        }

        if (edges.contains(.all) || edges.contains(.top)) {
            let topBorder = createBorder()
            self.addSubview(topBorder)
            NSLayoutConstraint.activate([
                topBorder.topAnchor.constraint(equalTo: self.topAnchor),
                topBorder.leadingAnchor.constraint(equalTo: self.leadingAnchor),
                topBorder.trailingAnchor.constraint(equalTo: self.trailingAnchor),
                topBorder.heightAnchor.constraint(equalToConstant: width)
                ])
        }
        if (edges.contains(.all) || edges.contains(.left)) {
            let leftBorder = createBorder()
            self.addSubview(leftBorder)
            NSLayoutConstraint.activate([
                leftBorder.topAnchor.constraint(equalTo: self.topAnchor),
                leftBorder.bottomAnchor.constraint(equalTo: self.bottomAnchor),
                leftBorder.leadingAnchor.constraint(equalTo: self.leadingAnchor),
                leftBorder.widthAnchor.constraint(equalToConstant: width)
                ])
        }
        if (edges.contains(.all) || edges.contains(.right)) {
            let rightBorder = createBorder()
            self.addSubview(rightBorder)
            NSLayoutConstraint.activate([
                rightBorder.topAnchor.constraint(equalTo: self.topAnchor),
                rightBorder.bottomAnchor.constraint(equalTo: self.bottomAnchor),
                rightBorder.trailingAnchor.constraint(equalTo: self.trailingAnchor),
                rightBorder.widthAnchor.constraint(equalToConstant: width)
                ])
        }
        if (edges.contains(.all) || edges.contains(.bottom)) {
            let bottomBorder = createBorder()
            self.addSubview(bottomBorder)
            NSLayoutConstraint.activate([
                bottomBorder.bottomAnchor.constraint(equalTo: self.bottomAnchor),
                bottomBorder.leadingAnchor.constraint(equalTo: self.leadingAnchor),
                bottomBorder.trailingAnchor.constraint(equalTo: self.trailingAnchor),
                bottomBorder.heightAnchor.constraint(equalToConstant: width)
                ])
        }
    }
}

Answer 33

Use below code in viewDidLoad

- (void)viewDidLoad
{
    [super viewDidLoad];


    [self.view.layer setBorderWidth: 1.0];
    [self.view.layer setCornerRadius:8.0f];
    [self.view.layer setMasksToBounds:YES];
    [self.view.layer setBorderColor:[[UIColor colorWithRed:251.0f/255.0f green:185.0f/255.0f blue:23.0f/255.0f alpha:1.0f]];`

}

this code set red color border to your view