I'm extremely new to iOS development and ran into some trouble while building an app for a course.
I created a segmented control and its init function (shown below) is being called in the view controller class containing the segmented control. I was able to remove all borders and dividers of the segmented control from the segmented control class as follows:
import Foundation
import UIKit
class CashSegmentedControl: UISegmentedControl{
func initUI(){
removeBorders()
}
func removeBorders(){
self.tintColor = UIColor.clear
}

I want it to have a line under each segment WHEN the segment is selected (similar to instagram)

I've searched a lot and come across some posts on StackOverflow but they seem to be for older versions of Swift. I'd really appreciate any help in this matter, and if there is a better solution for customising the borders (other than what I have done), I'd love to learn more!
Thanks a lot :)
Add the following code in a separate swift file (command+N -> New File):
extension UISegmentedControl{
func removeBorder(){
let backgroundImage = UIImage.getColoredRectImageWith(color: UIColor.white.cgColor, andSize: self.bounds.size)
self.setBackgroundImage(backgroundImage, for: .normal, barMetrics: .default)
self.setBackgroundImage(backgroundImage, for: .selected, barMetrics: .default)
self.setBackgroundImage(backgroundImage, for: .highlighted, barMetrics: .default)
let deviderImage = UIImage.getColoredRectImageWith(color: UIColor.white.cgColor, andSize: CGSize(width: 1.0, height: self.bounds.size.height))
self.setDividerImage(deviderImage, forLeftSegmentState: .selected, rightSegmentState: .normal, barMetrics: .default)
self.setTitleTextAttributes([NSForegroundColorAttributeName: UIColor.gray], for: .normal)
self.setTitleTextAttributes([NSForegroundColorAttributeName: UIColor(red: 67/255, green: 129/255, blue: 244/255, alpha: 1.0)], for: .selected)
}
func addUnderlineForSelectedSegment(){
removeBorder()
let underlineWidth: CGFloat = self.bounds.size.width / CGFloat(self.numberOfSegments)
let underlineHeight: CGFloat = 2.0
let underlineXPosition = CGFloat(selectedSegmentIndex * Int(underlineWidth))
let underLineYPosition = self.bounds.size.height - 1.0
let underlineFrame = CGRect(x: underlineXPosition, y: underLineYPosition, width: underlineWidth, height: underlineHeight)
let underline = UIView(frame: underlineFrame)
underline.backgroundColor = UIColor(red: 67/255, green: 129/255, blue: 244/255, alpha: 1.0)
underline.tag = 1
self.addSubview(underline)
}
func changeUnderlinePosition(){
guard let underline = self.viewWithTag(1) else {return}
let underlineFinalXPosition = (self.bounds.width / CGFloat(self.numberOfSegments)) * CGFloat(selectedSegmentIndex)
UIView.animate(withDuration: 0.1, animations: {
underline.frame.origin.x = underlineFinalXPosition
})
}
}
extension UIImage{
class func getColoredRectImageWith(color: CGColor, andSize size: CGSize) -> UIImage{
UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
let graphicsContext = UIGraphicsGetCurrentContext()
graphicsContext?.setFillColor(color)
let rectangle = CGRect(x: 0.0, y: 0.0, width: size.width, height: size.height)
graphicsContext?.fill(rectangle)
let rectangleImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return rectangleImage!
}
}
Then after call segmentedControl.addUnderlineForSelectedSegment()
from your viewDidLoad()
method, and create an @IBAction
method for the segmented control like so:
@IBAction func segmentedControlDidChange(_ sender: UISegmentedControl){
segmentedControl.changeUnderlinePosition()
}
Then call segmentedControl.changeUnderlinePosition()
from within this method.
Do not forget to connect the segmented control from your storyboard to the @IBAction
method you just created.
Very important: Don't forget to use Auto layout in the storyboard to determine the size and position of your segmented control.
This is the result:
Feel free to ask any other questions you may have :)
A.Jam's answer in Xcode 9.3, Swift 4.2 version
import UIKit
extension UISegmentedControl {
func removeBorder(){
let backgroundImage = UIImage.getColoredRectImageWith(color: UIColor.white.cgColor, andSize: self.bounds.size)
self.setBackgroundImage(backgroundImage, for: .normal, barMetrics: .default)
self.setBackgroundImage(backgroundImage, for: .selected, barMetrics: .default)
self.setBackgroundImage(backgroundImage, for: .highlighted, barMetrics: .default)
let deviderImage = UIImage.getColoredRectImageWith(color: UIColor.white.cgColor, andSize: CGSize(width: 1.0, height: self.bounds.size.height))
self.setDividerImage(deviderImage, forLeftSegmentState: .selected, rightSegmentState: .normal, barMetrics: .default)
self.setTitleTextAttributes([NSAttributedStringKey.foregroundColor: UIColor.gray], for: .normal)
self.setTitleTextAttributes([NSAttributedStringKey.foregroundColor: UIColor(red: 67/255, green: 129/255, blue: 244/255, alpha: 1.0)], for: .selected)
}
func addUnderlineForSelectedSegment(){
removeBorder()
let underlineWidth: CGFloat = self.bounds.size.width / CGFloat(self.numberOfSegments)
let underlineHeight: CGFloat = 2.0
let underlineXPosition = CGFloat(selectedSegmentIndex * Int(underlineWidth))
let underLineYPosition = self.bounds.size.height - 1.0
let underlineFrame = CGRect(x: underlineXPosition, y: underLineYPosition, width: underlineWidth, height: underlineHeight)
let underline = UIView(frame: underlineFrame)
underline.backgroundColor = UIColor(red: 67/255, green: 129/255, blue: 244/255, alpha: 1.0)
underline.tag = 1
self.addSubview(underline)
}
func changeUnderlinePosition(){
guard let underline = self.viewWithTag(1) else {return}
let underlineFinalXPosition = (self.bounds.width / CGFloat(self.numberOfSegments)) * CGFloat(selectedSegmentIndex)
UIView.animate(withDuration: 0.1, animations: {
underline.frame.origin.x = underlineFinalXPosition
})
}
}
extension UIImage {
class func getColoredRectImageWith(color: CGColor, andSize size: CGSize) -> UIImage{
UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
let graphicsContext = UIGraphicsGetCurrentContext()
graphicsContext?.setFillColor(color)
let rectangle = CGRect(x: 0.0, y: 0.0, width: size.width, height: size.height)
graphicsContext?.fill(rectangle)
let rectangleImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return rectangleImage!
}
}
you can use this
let segmentBottomBorder = CALayer()
segmentBottomBorder?.borderColor = UIColor.blue.cgColor
segmentBottomBorder?.borderWidth = 3
let x = CGFloat(sender.selectedSegmentIndex) * width
let y = sender.frame.size.height - (segmentBottomBorder?.borderWidth)!
let width: CGFloat = sender.frame.size.width/3
segmentBottomBorder?.frame = CGRect(x: x, y: y, width: width, height: (segmentBottomBorder?.borderWidth)!)
sender.layer.addSublayer(segmentBottomBorder!)
A.Jam's answer in Xcode 10.1, Swift 4.2 version - without UIImage Extension
and a grey underline for all segmentIndexes
extension UISegmentedControl {
func removeBorder(){
self.tintColor = UIColor.clear
self.backgroundColor = UIColor.clear
self.setTitleTextAttributes( [NSAttributedString.Key.foregroundColor : UIColor.orange], for: .selected)
self.setTitleTextAttributes( [NSAttributedString.Key.foregroundColor : UIColor.gray], for: .normal)
}
func setupSegment() {
self.removeBorder()
let segmentUnderlineWidth: CGFloat = self.bounds.width
let segmentUnderlineHeight: CGFloat = 2.0
let segmentUnderlineXPosition = self.bounds.minX
let segmentUnderLineYPosition = self.bounds.size.height - 1.0
let segmentUnderlineFrame = CGRect(x: segmentUnderlineXPosition, y: segmentUnderLineYPosition, width: segmentUnderlineWidth, height: segmentUnderlineHeight)
let segmentUnderline = UIView(frame: segmentUnderlineFrame)
segmentUnderline.backgroundColor = UIColor.gray
self.addSubview(segmentUnderline)
self.addUnderlineForSelectedSegment()
}
func addUnderlineForSelectedSegment(){
let underlineWidth: CGFloat = self.bounds.size.width / CGFloat(self.numberOfSegments)
let underlineHeight: CGFloat = 2.0
let underlineXPosition = CGFloat(selectedSegmentIndex * Int(underlineWidth))
let underLineYPosition = self.bounds.size.height - 1.0
let underlineFrame = CGRect(x: underlineXPosition, y: underLineYPosition, width: underlineWidth, height: underlineHeight)
let underline = UIView(frame: underlineFrame)
underline.backgroundColor = UIColor.orange
underline.tag = 1
self.addSubview(underline)
}
func changeUnderlinePosition(){
guard let underline = self.viewWithTag(1) else {return}
let underlineFinalXPosition = (self.bounds.width / CGFloat(self.numberOfSegments)) * CGFloat(selectedSegmentIndex)
underline.frame.origin.x = underlineFinalXPosition
}
}
来源:https://stackoverflow.com/questions/42755590/how-to-display-only-bottom-border-for-selected-item-in-uisegmentedcontrol