Add bottom line to view in SwiftUI / Swift / Objective-C / Xamarin

Question

I would like to keep the border at the bottom part only in UITextField. But I don\'t know how we can keep it on the bottom side.

Can you please advise m

Answer 1

I am creating custom textField to make it reusable component for SwiftUI

SwiftUI

struct CustomTextField: View {
    var placeHolder: String
    @Binding var value: String
    
    var lineColor: Color
    var width: CGFloat
    
    var body: some View {
        VStack {
            TextField(self.placeHolder, text: $value)
            .padding()
            .font(.title)
            
            Rectangle().frame(height: self.width)
                .padding(.horizontal, 20).foregroundColor(self.lineColor)
        }
    }
}

Usage:

@Binding var userName: String
@Binding var password: String

var body: some View {
    VStack(alignment: .center) {
        CustomTextField(placeHolder: "Username", value: $userName, lineColor: .white, width: 2)
        CustomTextField(placeHolder: "Password", value: $password, lineColor: .white, width: 2)
    }
}

---

---

Swift 5.0

I am using Visual Formatting Language (VFL) here, This will allow adding a line to any UIControl.

You can create a UIView extension class like UIView+Extention.swift

import UIKit

enum LinePosition {
    case top
    case bottom
}

extension UIView {
    func addLine(position: LinePosition, color: UIColor, width: Double) {
        let lineView = UIView()
        lineView.backgroundColor = color
        lineView.translatesAutoresizingMaskIntoConstraints = false // This is important!
        self.addSubview(lineView)

        let metrics = ["width" : NSNumber(value: width)]
        let views = ["lineView" : lineView]
        self.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:|[lineView]|", options:NSLayoutConstraint.FormatOptions(rawValue: 0), metrics:metrics, views:views))

        switch position {
        case .top:
            self.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:|[lineView(width)]", options:NSLayoutConstraint.FormatOptions(rawValue: 0), metrics:metrics, views:views))
            break
        case .bottom:
            self.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:[lineView(width)]|", options:NSLayoutConstraint.FormatOptions(rawValue: 0), metrics:metrics, views:views))
            break
        }
    }
}

Usage:

textField.addLine(position: .LINE_POSITION_BOTTOM, color: .darkGray, width: 0.5)

---

Objective C:

You can add this helper method to your global helper class(I used global class method) or in the same view controller(using an instance method).

typedef enum : NSUInteger {
    LINE_POSITION_TOP,
    LINE_POSITION_BOTTOM
} LINE_POSITION;


- (void) addLine:(UIView *)view atPosition:(LINE_POSITION)position withColor:(UIColor *)color lineWitdh:(CGFloat)width {
    // Add line
    UIView *lineView = [[UIView alloc] init];
    [lineView setBackgroundColor:color];
    [lineView setTranslatesAutoresizingMaskIntoConstraints:NO];
    [view addSubview:lineView];
    
    NSDictionary *metrics = @{@"width" : [NSNumber numberWithFloat:width]};
    NSDictionary *views = @{@"lineView" : lineView};
    [view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[lineView]|" options: 0 metrics:metrics views:views]];
    
    switch (position) {
        case LINE_POSITION_TOP:
            [view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-0-[lineView(width)]" options: 0 metrics:metrics views:views]];
            break;
            
        case LINE_POSITION_BOTTOM:
            [view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[lineView(width)]|" options: 0 metrics:metrics views:views]];
            break;
        default: break;
    }
}

Usage:

[self addLine:self.textField atPosition:LINE_POSITION_TOP withColor:[UIColor darkGrayColor] lineWitdh:0.5];

---

Xamarin code:

 var border = new CALayer();
 nfloat width = 2;
 border.BorderColor = UIColor.Black.CGColor;
 border.Frame = new CoreGraphics.CGRect(0, textField.Frame.Size.Height - width, textField.Frame.Size.Width, textField.Frame.Size.Height);
 border.BorderWidth = width;
 textField.Layer.AddSublayer(border);
 textField.Layer.MasksToBounds = true;

Answer 2

None of these solutions really met my expectations. I wanted to subclass the TextField since I don't want to set the border manually all the time. I also wanted to change the border color e.g. for an error. So here's my solution with Anchors:

class CustomTextField: UITextField {

    var bottomBorder = UIView()

    override func awakeFromNib() {

            // Setup Bottom-Border

            self.translatesAutoresizingMaskIntoConstraints = false

            bottomBorder = UIView.init(frame: CGRect(x: 0, y: 0, width: 0, height: 0))
            bottomBorder.backgroundColor = UIColor(rgb: 0xE2DCD1) // Set Border-Color
            bottomBorder.translatesAutoresizingMaskIntoConstraints = false

            addSubview(bottomBorder)

            bottomBorder.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true
            bottomBorder.leftAnchor.constraint(equalTo: leftAnchor).isActive = true
            bottomBorder.rightAnchor.constraint(equalTo: rightAnchor).isActive = true
            bottomBorder.heightAnchor.constraint(equalToConstant: 1).isActive = true // Set Border-Strength

    }
}

---- Optional ----

To change the color add sth like this to the CustomTextField Class:

@IBInspectable var hasError: Bool = false {
    didSet {

        if (hasError) {

            bottomBorder.backgroundColor = UIColor.red

        } else {

            bottomBorder.backgroundColor = UIColor(rgb: 0xE2DCD1)

        }

    }
}

And to trigger the Error call this after you created an instance of CustomTextField

textField.hasError = !textField.hasError

Hope it helps someone ;)

Answer 3

 extension UITextField {  
  func setBottomBorder(color:String) {
    self.borderStyle = UITextBorderStyle.None
    let border = CALayer()
    let width = CGFloat(1.0)
    border.borderColor = UIColor(hexString: color)!.cgColor
    border.frame = CGRect(x: 0, y: self.frame.size.height - width,   width:  self.frame.size.width, height: self.frame.size.height)
    border.borderWidth = width
    self.layer.addSublayer(border)
    self.layer.masksToBounds = true
   }
}

and then just do this:

yourTextField.setBottomBorder(color: "#3EFE46")

Answer 4

You can use this ORGANIZED and can also CUSTOMIZE this extension further:

"One Line Implementation" in viewDidAppear(so that frame size will be correct):

// Add layer in your textfield    
yourTextField.addLayer(.bottom).addPadding(.left)


// Extension
    extension UITextField {

    enum Position {
        case up, bottom, right, left
    }

    //  MARK: - Add Single Line Layer
    func addLayer(_ position: Position) -> UITextField {

        // bottom layer
        let bottomLayer = CALayer()
        // set width
        let height = CGFloat(1.0)
        bottomLayer.borderWidth = height
        // set color
        bottomLayer.borderColor = UIColor.white.cgColor
        // set frame
        // y position changes according to the position
        let yOrigin = position == .up ? 0.0 : frame.size.height - height
        bottomLayer.frame = CGRect.init(x: 0, y: yOrigin, width: frame.size.width, height: height)
        layer.addSublayer(bottomLayer)
        layer.masksToBounds = true

        return self
    }

    // Add right/left padding view in textfield
    func addPadding(_ position: Position, withImage image: UIImage? = nil) {
        let paddingHeight = frame.size.height
        let paddingViewFrame = CGRect.init(x: 0.0, y: 0.0, width: paddingHeight * 0.6, height: paddingHeight)
        let paddingImageView = UIImageView.init(frame: paddingViewFrame)
        paddingImageView.contentMode = .scaleAspectFit

        if let paddingImage = image {
            paddingImageView.image = paddingImage
        }

        // Add Left/Right view mode
        switch position {
        case .left:
            leftView        = paddingImageView
            leftViewMode    = .always
        case .right:
            rightView       = paddingImageView
            rightViewMode    = .always
        default:
            break
        }
    }
}

Answer 5

If you want to do without knowing frames beforehand, without subclassing and without Autolayout:

Swift 5 / Swift 4.x / Swift 3.x

extension UITextField {
  func setBottomBorder() {
    self.borderStyle = .none
    self.layer.backgroundColor = UIColor.white.cgColor

    self.layer.masksToBounds = false
    self.layer.shadowColor = UIColor.gray.cgColor
    self.layer.shadowOffset = CGSize(width: 0.0, height: 1.0)
    self.layer.shadowOpacity = 1.0
    self.layer.shadowRadius = 0.0
  }
}

Call as yourTextField.setBottomBorder() from anywhere without making sure of the frames to be right.

The Result looks like this:

Swift UI

struct MyTextField: View {
  var myPlaceHolder: String
  @Binding var text: String

  var underColor: Color
  var height: CGFloat

  var body: some View {
    VStack {
        TextField(self.myPlaceHolder, text: $text)
        .padding()
        .font(.title)

        Rectangle().frame(height: self.height)
            .padding(.horizontal, 24).foregroundColor(self.underColor)
    }
  }
}

Answer 6

Swift 5 You can use a UIView extension so that you can add bottom border to any view:

extension UIView {

    func addBottomLine(width: CGFloat, color: UIColor) {
        let lineView: UIView = {
            let view = UIView()
            view.translatesAutoresizingMaskIntoConstraints = false
            view.backgroundColor = color
            return view
        }()
        addSubview(lineView)
        NSLayoutConstraint.activate([
            lineView.heightAnchor.constraint(equalToConstant: width),
            lineView.leadingAnchor.constraint(equalTo: leadingAnchor),
            lineView.trailingAnchor.constraint(equalTo: trailingAnchor),
            lineView.bottomAnchor.constraint(equalTo: bottomAnchor)
        ])
    }

}