I want to make a UIView stick on the bottom while I am scrolling in my UITableView.
My idea was to set a UIView with the position of right above the navigation item. Set it's zPosition to 1.
The problem is, that the yPosition of my UITableView varies.
Any idea how to solve this?
Edit:
Providing Screenshots for visible vs. expected behaviour:
Visible:
This is when I scroll:
Expected:
As seen on Tinder Camera Symbol above Table:
Edit2:
This code is what I use to put the rectangle to the bottom.
It works until I swipe the UITableView - The rectangle also scrolls up.
let bounds = self.view.bounds
let yPosition = self.navigationController?.toolbar.frame.minY
print(yPosition)
let myView = UIView(frame: CGRect(x: 0, y: yPosition! - bounds.height/6, width: bounds.width, height: bounds.height/6))
myView.backgroundColor = myColor.rookie
myView.alpha = 0.8
myView.layer.zPosition = 1
myView.isUserInteractionEnabled = true
self.view.addSubview(myView)
there is a solution for this. you can do this by disabling the Auto Layout(button.translatesAutoresizingMaskIntoConstraints = false) property of the corresponding Button or any UIView for floating button:
Swift 4
button.translatesAutoresizingMaskIntoConstraints = false
if #available(iOS 11.0, *) {
button.rightAnchor.constraint(equalTo: tableView.safeAreaLayoutGuide.rightAnchor, constant: -10).isActive = true
button.bottomAnchor.constraint(equalTo: tableView.safeAreaLayoutGuide.bottomAnchor, constant: -10).isActive = true
} else {
button.rightAnchor.constraint(equalTo: tableView.layoutMarginsGuide.rightAnchor, constant: 0).isActive = true
button.bottomAnchor.constraint(equalTo: tableView.layoutMarginsGuide.bottomAnchor, constant: -10).isActive = true
}
Related
I am trying to code the label in the viewDidLoad function. The label is showing up but the code I am using now is not affecting the positioning. I am trying to code everything in the viewDidLoad function. You can see the screenshot below.
override func viewDidLoad() {
super.viewDidLoad()
let backbutton = UILabel()
backbutton.backgroundColor = UIColor.orange
backbutton.translatesAutoresizingMaskIntoConstraints = false
backbutton.widthAnchor.constraint(equalToConstant: 300).isActive = true
backbutton.heightAnchor.constraint(equalToConstant: 300).isActive = true
backbutton.centerXAnchor.constraint(equalTo: backbutton.centerXAnchor, constant: 100).isActive = true
backbutton.centerYAnchor.constraint(equalTo: backbutton.centerYAnchor, constant: 300).isActive = true
view.addSubview(backbutton)
}
This is how you can align the label into the center of the view,
let backbutton = UILabel()
view.addSubview(backbutton)
backbutton.backgroundColor = UIColor.orange
backbutton.translatesAutoresizingMaskIntoConstraints = false
backbutton.widthAnchor.constraint(equalToConstant: 300).isActive = true
backbutton.heightAnchor.constraint(equalToConstant: 300).isActive = true
backbutton.centerXAnchor.constraint(equalTo: view.centerXAnchor, constant: 0).isActive = true
backbutton.centerYAnchor.constraint(equalTo: view.centerYAnchor, constant: 0).isActive = true
When you are setting constraints programmatically, make sure you add the view into the super/parent view before applying constraints. Secondly in the below lines, you are telling the backButton label to align its center to itself (i.e, backbutton.centerXAnchor.constraint(equalTo: backbutton.centerXAnchor).
backbutton.centerXAnchor.constraint(equalTo: backbutton.centerXAnchor, constant: 100).isActive = true
backbutton.centerYAnchor.constraint(equalTo: backbutton.centerYAnchor, constant: 300).isActive = true
As you want to align it center vertically and horizontally to its parent view so you should set the center constraints equal to parent view as below,
backbutton.centerXAnchor.constraint(equalTo: view.centerXAnchor, constant: 0).isActive = true
backbutton.centerYAnchor.constraint(equalTo: view.centerYAnchor, constant: 0).isActive = true
Try this!!
self.view.setNeedsUpdateConstraints()
self.view.layoutIfNeeded()
Try using CGRect instead:
let screenWidth = UIScreen.main.bounds.width
let screenHeight = UIScreen.main.bounds.height
let xPostion:CGFloat = screenWidth - 150 //150 is half of view's width
let yPostion:CGFloat = screenHeight - 150 //150 is half of view's height
let buttonWidth:CGFloat = 300
let buttonHeight:CGFloat = 300
backbutton.frame = CGRect(x:xPostion, y:yPostion, width:buttonWidth, height:buttonHeight)
instead of screen width/height you can also try to get the width of your super view using:
self.view.frame.width
self.view.frame.height
I am trying to write a simple composite component for iOS in Swift 3. It consists of a UILabel followed by an UITextField laid out horizontally followed by a line under them. But What happens is the UILabel disappears, UITextField appears on the parent view and line also disappears.
My design in sketch
What it actually looks like in the Storyboard
My component's constraints in the view controller
My intention was to use Auto Layout, anchor the label to top and leading anchors of the view, anchor the textfield to top of the view and trailing anchor of the label with a constant, so they would appear side by side.
I did do a lot of research on this, one site that looked pretty close to what I wanted was https://www.raywenderlich.com/125718/coding-auto-layout, and I think I am following more or less the same approach.
I am doing something obviously wrong, but can't figure out what. Any help is much appreciated, I have been at this for a few days now.
import UIKit
#IBDesignable
class OTextEdit: UIView {
#IBInspectable var LabelText: String = "Label"
#IBInspectable var SecureText: Bool = false
#IBInspectable var Color: UIColor = UIColor.black
#IBInspectable var Text: String = "" {
didSet {
edit.text = Text
}
}
fileprivate let label = UILabel(frame: CGRect(x: 0, y: 0, width: 200, height: 35))
fileprivate let edit = UITextField(frame: CGRect(x: 210, y: 0, width: 200, height: 35))
fileprivate let line: UIView = UIView()
override var intrinsicContentSize: CGSize {
return CGSize(width: 300, height: 100)
}
func setup() {
label.text = LabelText
label.textColor = Color
label.font = UIFont(name: "Avenir Next Condensed", size: 24)
edit.font = UIFont(name: "Avenir Next Condensed", size: 24)
edit.borderStyle = .roundedRect
edit.isSecureTextEntry = SecureText
line.backgroundColor = UIColor.white
self.addSubview(label)
self.addSubview(edit)
self.addSubview(line)
}
override func willMove(toSuperview newSuperview: UIView?) {
super.willMove(toSuperview: newSuperview)
setup()
setupConstaints()
}
func setupConstaints() {
label.translatesAutoresizingMaskIntoConstraints = false
edit.translatesAutoresizingMaskIntoConstraints = false
line.translatesAutoresizingMaskIntoConstraints = false
label.leadingAnchor.constraint(equalTo: leadingAnchor, constant: -10).isActive = true
label.topAnchor.constraint(equalTo: topAnchor)
edit.leadingAnchor.constraint(equalTo: label.leadingAnchor, constant: 10).isActive = true
edit.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: -20).isActive = true
edit.topAnchor.constraint(equalTo: self.topAnchor)
line.heightAnchor.constraint(equalToConstant: 2.0).isActive = true
line.leadingAnchor.constraint(equalTo: self.leadingAnchor, constant: 10).isActive = true
line.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: -20).isActive = true
line.topAnchor.constraint(equalTo: label.bottomAnchor, constant: 1.0).isActive = true
}
}
You haven't got a series of constraints top to bottom, so auto layout can't determine the content size of your object. You have tried to set this via the initrinsicContentSize but you shouldn't need to do this.
You also need to set a horizontal hugging priority for your label to let auto layout know that you want the text field to expand:
I removed your override of intrinsicContentSize and changed your constraints to:
Constrain the bottom of the label to the top of the line
Constrain the bottom of the line to the bottom of the superview
Constrain the baseline of the label to the baseline of the text field
Remove the constraint between the top of the text field and the superview
Set the horizontal hugging priority of the label.
func setupConstraints() {
label.translatesAutoresizingMaskIntoConstraints = false
edit.translatesAutoresizingMaskIntoConstraints = false
line.translatesAutoresizingMaskIntoConstraints = false
label.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 10).isActive = true
label.setContentHuggingPriority(.defaultHigh, for: .horizontal)
label.topAnchor.constraint(equalTo: topAnchor)
label.bottomAnchor.constraint(equalTo: line.topAnchor, constant: -8).isActive = true
edit.leadingAnchor.constraint(equalTo: label.trailingAnchor, constant: 10).isActive = true
edit.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: -20).isActive = true
edit.firstBaselineAnchor.constraint(equalTo: label.firstBaselineAnchor).isActive = true
line.heightAnchor.constraint(equalToConstant: 2.0).isActive = true
line.leadingAnchor.constraint(equalTo: self.leadingAnchor, constant: 10).isActive = true
line.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: -20).isActive = true
line.topAnchor.constraint(equalTo: label.bottomAnchor, constant: 1.0).isActive = true
line.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true
}
I think it is pretty close to what you are after.
I have a cake of 3 UIView layers with programmatically constraints.
Constructed function for programmatically set up constraints:
func setupViewConstraints(item:UIView, leadingTo:NSLayoutXAxisAnchor, leadingCon:CGFloat,
trailingTo:NSLayoutXAxisAnchor, trailingCon:CGFloat, topTo:NSLayoutYAxisAnchor,
topCon:CGFloat, bottomTo:NSLayoutYAxisAnchor, bottomCon:CGFloat) {
item.translatesAutoresizingMaskIntoConstraints = false
item.leadingAnchor.constraint(equalTo: leadingTo, constant: leadingCon).isActive = true
item.trailingAnchor.constraint(equalTo: trailingTo, constant: trailingCon).isActive = true
item.topAnchor.constraint(equalTo: topTo, constant:topCon).isActive = true
item.bottomAnchor.constraint(equalTo: bottomTo, constant:bottomCon).isActive = true
}
The lowest base layer is lightGray.
view = UIView()
view.backgroundColor = .lightGray
The 2nd layer contains 2 UIView (red and blue) with constraints .
let red = UIView()
red.backgroundColor = .red
view.addSubview(red)
setupViewConstraints(item: red, leadingTo: view.leadingAnchor, leadingCon: 0, trailingTo: view.trailingAnchor, trailingCon: -(view.frame.width)*0.2), topTo: view.topAnchor, topCon: 0, bottomTo: view.bottomAnchor, bottomCon: -(view.frame.width)*0.8)
let blue = UIView()
blue.backgroundColor = .blue
view.addSubview(blue)
setupViewConstraints(item: blue, leadingTo: view.leadingAnchor, leadingCon: 0, trailingTo: view.trailingAnchor, trailingCon: -(view.frame.width)*0.2), topTo: red.bottomAnchor, topCon: 0, bottomTo: view.bottomAnchor, bottomCon: 0)
And on top i have yellow UIView layer, which overlaps all the lower layers.
let yellow = UIView()
yellow.backgroundColor = .yellow
view.addSubview(yellow)
setupViewConstraints(item: yellow, leadingTo: view.leadingAnchor, leadingCon: 0, trailingTo: view.trailingAnchor, trailingCon: 0, topTo: view.topAnchor, topCon: 0, bottomTo: view.bottomAnchor, bottomCon: 0)
Also, i have UINavigationBar with UINavigationItem inside the yellow UIView.
//Add navigation item and buttons
naviItem = UINavigationItem()
naviItem.setRightBarButton(UIBarButtonItem(barButtonSystemItem:.add, target:self, action:#selector(goToDestVC)), animated: true)
naviItem.setLeftBarButton(UIBarButtonItem(image: UIImage(named: "hamburger_slim_30"), style: .plain, target: self, action: #selector(hamburgerBtnPressed)), animated: true)
//Add navigation bar with transparent background
naviBar = UINavigationBar()
naviBar.setBackgroundImage(UIImage(), for: .default)
naviBar.shadowImage = UIImage()
naviBar.isTranslucent = true
// Assign the navigation item to the navigation bar
naviBar.items = [naviItem]
view.addSubview(naviBar)
setupViewConstraints(item: naviBar, leadingTo: yellow.leadingAnchor, leadingCon: 0, trailingTo: yellow.trailingAnchor, trailingCon: 0, topTo: yellow.topAnchor, topCon: 0, bottomTo: yellow.bottomAnchor, bottomCon: -(view.frame.height)*0.9))
And i have hamburgerBtnPressed function, which should shift the yellow layer to the right by 80% (I change the values of leading and trailing constants by 80%), but this does not work!!!
var hamburgerMenuIsVisible = false
#objc func hamburgerBtnPressed(_ sender: Any) {
if !hamburgerMenuIsVisible {
let menuWidth = (self.view.frame.width)*0.8
setupViewConstraints(item: layoutView, leadingTo: view.leadingAnchor, leadingCon: menuWidth, trailingTo: view.trailingAnchor, trailingCon: menuWidth, topTo: view.topAnchor, topCon: 0, bottomTo: view.bottomAnchor, bottomCon: 0)
hamburgerMenuIsVisible = true
} else {
setupViewConstraints(item: layoutView, leadingTo: view.leadingAnchor, leadingCon: 0, trailingTo: view.trailingAnchor, trailingCon: 0, topTo: view.topAnchor, topCon: 0, bottomTo: view.bottomAnchor, bottomCon: 0)
hamburgerMenuIsVisible = false
}
// layoutIfNeeded() lays out the subviews immediately and forces the layout before drawing
UIView.animate(withDuration: 0.2, delay:0.0, options: .curveEaseIn, animations: {
self.view.layoutIfNeeded()
}) { (animationComplete) in
print("Animation is complete!")
}
}
But if I change the values of leading and trailing constants to negative, everything will work, and the menu will shift to the left without any problems.
let menuWidth = -(self.view.frame.width)*0.8
Please explain.. what's the issue? Why the yellow UIView shifted to the left with negative values of constraints, and does not work with positive values of constraints? and gives an error:
Probably at least one of the constraints in the following list is one you don't want.
(
"<NSLayoutConstraint:0x6040002853c0 UIView:0x7fa947c35850.trailing == UIView:0x7fa947e1d2d0.trailing (active)>",
"<NSLayoutConstraint:0x604000092750 UIView:0x7fa947c35850.trailing == UIView:0x7fa947e1d2d0.trailing + 331.2 (active)>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x604000092750 UIView:0x7fa947c35850.trailing == UIView:0x7fa947e1d2d0.trailing + 331.2 (active)>
Update: I have choose Option 2:
Keep a reference to the constraint that you want to change and just adjust its constant. Need to call setNeedsLayout too before layoutIfNeeded.
Updated code:
var leadingC: NSLayoutConstraint!
var trailingC: NSLayoutConstraint!
var yellow: UIView!
loadView():
yellow = UIView()
yellow.backgroundColor = .yellow
view.addSubview(yellow)
//Set up leading and trailing constraints for handling yellow view shift
leadingC = yellow.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 0)
trailingC = yellow.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: 0)
//Put leadingC.constant and trailingC.constant into the function
setupViewConstraints(item: yellow, leadingTo: view.leadingAnchor, leadingCon: leadingC!.constant, trailingTo: view.trailingAnchor, trailingCon: trailingC.constant, topTo: view.topAnchor, topCon: 0, bottomTo: view.bottomAnchor, bottomCon: 0)
Updated Hamburger function:
#objc func hamburgerBtnPressed(_ sender: Any) {
if !hamburgerMenuIsVisible {
let menuWidth = (self.view.frame.width)*0.8
leadingC!.constant = menuWidth
trailingC!.constant = menuWidth
print(leadingC.constant, trailingC.constant)
hamburgerMenuIsVisible = true
} else {
leadingC!.constant = 0
trailingC!.constant = 0
hamburgerMenuIsVisible = false
}
// layoutIfNeeded() lays out the subviews immediately and forces the layout before drawing
UIView.animate(withDuration: 0.2, delay:0.0, options: .curveEaseIn, animations: {
self.view.setNeedsLayout()
self.view.layoutIfNeeded()
}) { (animationComplete) in
print("Animation is complete!")
}
}
var hamburgerMenuIsVisible = false
I have no errors and "Animation complete!" was printed too, but nothing happens on the screen, no animation.
Firstly, it needs negative values because the constraints need to be set up in the correct direction. Change this and you can remove all of those negative constants:
item.leadingAnchor.constraint(equalTo: leadingTo, constant: leadingCon).isActive = true
item.trailingAnchor.constraint(equalTo: trailingTo, constant: trailingCon).isActive = true
item.topAnchor.constraint(equalTo: topTo, constant:topCon).isActive = true
item.bottomAnchor.constraint(equalTo: bottomTo, constant:bottomCon).isActive = true
to
item.leadingAnchor.constraint(equalTo: leadingTo, constant: leadingCon).isActive = true
trailingTo.constraint(equalTo: item.trailingAnchor, constant: trailingCon).isActive = true
item.topAnchor.constraint(equalTo: topTo, constant:topCon).isActive = true
bottomTo.constraint(equalTo: item.bottomAnchor, constant:bottomCon).isActive = true
Secondly, every time you call setupViewConstraints you are creating and activating another set of constraints.
Option 1:
Remove all constraints for the yellow view before setting them up again.
Option 2:
Keep a reference to the constraint that you want to change and just adjust its constant. You may need to call setNeedsLayout too before layoutIfNeeded.
Option 3:
Add 2 contraints. The initial leading constraint, and one with the width you desire. Change the priority of the first constraint to 999 (default is 1000) and toggle the isActive property of the other when you want to show/hide the menu.
let leading = yellow.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 0)
leading.priority = UILayoutPriority(999)
leading.isActive = true
let otherConstraint = yellow.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: (view.frame.width)*0.8)
otherConstraint.isActive = false // toggle this property to show/hide
Option 2 is probably going to be the best for performance. From the apple docs:
Setting the constant on an existing constraint performs much better
than removing the constraint and adding a new one that's exactly like
the old except that it has a different constant
I have UISearchBar in the UINavigationController. The search bar appears good in portrait but in a landscape, it appears to half of screen. It doesn't cover the full width.
I tried the following but it doesn't work.
searchBar.frame = CGRect(x: 0, y: 0, width: (navigationController?.view.bounds.size.width)!, height: 64)
view.addSubview(searchBar)
let guide = self.view.safeAreaLayoutGuide
searchBar.leadingAnchor.constraint(equalTo: guide.leadingAnchor, constant: 0).isActive = true
searchBar.trailingAnchor.constraint(equalTo: guide.trailingAnchor, constant: 0).isActive = true
I fixed it by adding the following two lines of code:
searchBar.autoresizesSubviews = true
searchBar.autoresizingMask = .flexibleWidth
I have added a scrollview subview in one of my views, but am having trouble getting it's height to accurately fit the content that the scrollview is showing, which is text in the UILabel. The height needs to be dynamic (i.e. a factor of the text length), because I am instantiating this view for many different text lengths. Whenever I log label.frame.bounds I get (0,0) back. I have also tried sizeToFits() in a few places without much luck.
My goal is to get the scrollview to end when it reaches the last line of text. Also, I am using only programmatic constraints.
A condensed version of my code is the following:
import UIKit
class ViewController: UIViewController, UIScrollViewDelegate {
let scrollView = UIScrollView()
let containerView = UIView()
let label = UILabel()
override func viewDidLoad() {
super.viewDidLoad()
scrollView.delegate = self
// This needs to change
scrollView.contentSize = CGSize(width: 375, height: 1000)
scrollView.addSubview(containerView)
view.addSubview(scrollView)
label.text = unknownAmountOfText()
label.backgroundColor = .gray
containerView.isUserInteractionEnabled = true
containerView.addSubview(label)
label.translatesAutoresizingMaskIntoConstraints = false
label.topAnchor.constraint(equalTo: containerView.topAnchor).isActive = true
label.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
scrollView.frame = view.bounds
containerView.frame = CGRect(x: 0, y: 0, width: scrollView.contentSize.width, height: scrollView.contentSize.height)
}
}
Any help is appreciated.
SOLUTION found:
func heightForLabel(text: String, font: UIFont, lineHeight: CGFloat, width: CGFloat) -> CGFloat {
let label:UILabel = UILabel(frame: CGRect(x: 0, y: 0, width: width, height: CGFloat.greatestFiniteMagnitude))
label.numberOfLines = 0
label.lineBreakMode = NSLineBreakMode.byWordWrapping
label.font = font
label.text = text
label.setLineHeight(lineHeight: lineHeight)
label.sizeToFit()
return label.frame.height
}
I found this solution online, that gives me what I need to set the appropriate content size for the scrollView height based on the label's height. Ideally, I'd be able to determine this without this function, but for now I'm satisfied.
The key to UIScrollView and its content size is setting your constraints so that the actual content defines the contentSize.
For a simple example: say you have a UIScrollView with width: 200 and height: 200. Now you put a UIView inside it, that has width: 100 and height: 400. The view should scroll up and down, but not left-right. You can constrain the view to 100x400, and then "pin" the top, bottom, left and right to the sides of the scroll view, and AutoLayout will "auto-magically" set the scrollview's contentSize.
When you add subviews that can change size - either explicitly (code, user interaction) or implicitly - if the constraints are set correctly those changes will also "auto-magically" adjust the scrollview's contentSize.
So... here is an example of what you are trying to do:
import UIKit
class ViewController: UIViewController, UIScrollViewDelegate {
let scrollView = UIScrollView()
let label = UILabel()
let s1 = "1. This is the first line of text in the label. It has words and punctuation, but no embedded line-breaks, so what you see here is normal UILabel word-wrapping."
var counter = 1
override func viewDidLoad() {
super.viewDidLoad()
// turn off translatesAutoresizingMaskIntoConstraints, because we're going to set them
scrollView.translatesAutoresizingMaskIntoConstraints = false
label.translatesAutoresizingMaskIntoConstraints = false
// set background colors, just so we can see the bounding boxes
self.view.backgroundColor = UIColor(red: 1.0, green: 0.7, blue: 0.3, alpha: 1.0)
scrollView.backgroundColor = UIColor(red: 0.8, green: 0.8, blue: 1.0, alpha: 1.0)
label.backgroundColor = UIColor(white: 0.9, alpha: 1.0)
// add the label to the scrollView, and the scrollView to the "main" view
scrollView.addSubview(label)
self.view.addSubview(scrollView)
// set top, left, right constraints on scrollView to
// "main" view + 8.0 padding on each side
scrollView.topAnchor.constraint(equalTo: self.topLayoutGuide.bottomAnchor, constant: 8.0).isActive = true
scrollView.leadingAnchor.constraint(equalTo: self.view.leadingAnchor, constant: 8.0).isActive = true
scrollView.trailingAnchor.constraint(equalTo: self.view.trailingAnchor, constant: -8.0).isActive = true
// set the height constraint on the scrollView to 0.5 * the main view height
scrollView.heightAnchor.constraint(equalTo: self.view.heightAnchor, multiplier: 0.5).isActive = true
// set top, left, right AND bottom constraints on label to
// scrollView + 8.0 padding on each side
label.topAnchor.constraint(equalTo: scrollView.topAnchor, constant: 8.0).isActive = true
label.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor, constant: 8.0).isActive = true
label.trailingAnchor.constraint(equalTo: scrollView.trailingAnchor, constant: -8.0).isActive = true
label.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor, constant: -8.0).isActive = true
// set the width of the label to the width of the scrollView (-16 for 8.0 padding on each side)
label.widthAnchor.constraint(equalTo: scrollView.widthAnchor, constant: -16.0).isActive = true
// configure label: Zero lines + Word Wrapping
label.numberOfLines = 0
label.lineBreakMode = NSLineBreakMode.byWordWrapping
label.font = UIFont.systemFont(ofSize: 17.0)
// set the text of the label
label.text = s1
// ok, we're done... but let's add a button to change the label text, so we
// can "see the magic" happening
let b = UIButton(type: UIButtonType.system)
b.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview(b)
b.setTitle("Add a Line", for: .normal)
b.topAnchor.constraint(equalTo: scrollView.bottomAnchor, constant: 24.0).isActive = true
b.centerXAnchor.constraint(equalTo: self.view.centerXAnchor).isActive = true
b.addTarget(self, action: #selector(self.btnTap(_:)), for: .touchUpInside)
}
func btnTap(_ sender: Any) {
if let t = label.text {
counter += 1
label.text = t + "\n\n\(counter). Another line"
}
}
}
give top,left,right and bottom constraint to label with containerView.
and
set label.numberOfLines = 0
also ensure that you have given top, left, right and bottom constraint to containerView. this will solve your issue
Set the auto layout constraints from the interface builder as shown in image .
enter image description here
I set the height of UIScrollView as 0.2 of the UIView
Then drag the UIlabel from MainStoryBoard to the view controller.
Add this two lines in viewdidload method.
draggedlabel.numberOfLines = 0
draggedlabel.lineBreakMode = NSLineBreakMode.byWordWrapping