My view (in the Main.storyboard) contains another UIView which takes only about 80% of the screen's height (set with constraints).
In this second view (I call it the viewContainer) I want to display different views, which works with
viewContainer.bringSubview(toFront: someView)
I created a new group in my project which contains 3 UIViewController classes and 3 xib files which I want to display in my viewContainer.
For each of those xib files I changed the background color to something unique so I can tell if it's working. And it does so far.
Now I tried adding a UIButton to the first UIViewController class and added an #IBAction for it. That just prints text to the console.
When I run the app I can switch between my 3 classes (3 different background colors) and I can also see and click the button I added to the first class when I select it.
But the code is never executed and my console is empty. Is that because my 3 other Views are not shown in my Main.storyboard?
SimpleVC1.swift
import UIKit
class SimpleVC1: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func onButtonPressed(_ sender: Any) {
print("test")
}
}
Try using a target instead (and programmatically create the button), it might be easier:
import UIKit
class SimpleVC1: UIViewController {
var button = UIButton()
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(button)
button.frame.size = CGSize(width: 100, height: 100)
button.center = CGPoint(x: 100, y: 100)
button.setTitle("Control 1", for: .normal)
button.addTarget(self, action: #selector(control1), for: .touchUpInside)
button.backgroundColor = UIColor.blue
button.setTitleColor(UIColor.white, for: .normal)
}
#objc func control1() {
//Add your code for when the button is pressed here
button.backgroundColor = UIColor.red
}
}
Related
I have been trying to fix an issue that I encountered with a tableviewcontroller.
The sections within the tableviewcontroller are views:
override func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
let sectionLabel = UILabel()
sectionLabel.text = Catalog.sharedInstance.allSections[section - 1].name.localized(lang: defaults.string(forKey: "language")!)
sectionLabel.font = UIFont(name: "Centabel Book", size: 25)
sectionLabel.backgroundColor = UIColor.white
sectionLabel.clipsToBounds = true
return sectionLabel
}
If I try to add a button programatically to put it over the tableview
let actionButton = JJFloatingActionButton()
override func viewDidLoad() {
super.viewDidLoad()
// Configuration of the Floating Action Button
actionButton.buttonColor = .red
actionButton.addItem { item in
self.performSegue(withIdentifier: "goToSettings", sender: nil)
}
actionButton.display(inViewController: self)
actionButton.clipsToBounds = true
// This doesn't work. It is to bring the button to the front. Now it is hidden by the sections.
view.bringSubviewToFront(actionButton)
// Checks if the language setting is nil, which means it is the first time you run the application. If then... selects English as default.
if defaults.string(forKey: "language") == nil {
defaults.set("en", forKey: "language")
}
}
... I don't know why but the viewForHeaderInSection hides the button. You can check it in the picture below:
floating button hided by the headersection
I tried to use the method:
view.bringSubviewToFront(actionButton)
and also:
actionbutton.superview?.bringSubviewToFront(actionButton)
But none of this brings the button to the front.
I am using a floating action button from github called JJFloatingActionButton. But I tried to add a simple UIButton and I got the same error. This is the code that also gave me the same error inside viewDidLoad:
let button = UIButton(frame: CGRect(x: 100, y: 1000, width: 100, height: 50))
button.backgroundColor = .green
button.setTitle("Test Button", for: .normal)
button.addTarget(self, action: #selector(buttonAction), for: .touchUpInside)
self.view.addSubview(button)
Again the same error. You can check the picture:
adding a simple UIButton happens the same problem
May be you can help me with that.
Thanks in advance.
You could try to use a regular UIViewController (not UITableViewController) and add the UITableView by hand.
Like that you would have better control over the view hierarchy.
addTarget
So I know that you can use addTarget on a button
like so:
import UIKit
class ViewController: UIViewController {
func calledMethod(_ sender: UIButton!) {
print("Clicked")
}
override func viewDidLoad() {
super.viewDidLoad()
let btn = UIButton(frame: CGRect(x: 30, y: 30, width: 60, height: 30))
btn.backgroundColor = UIColor.darkGray
btn.addTarget(self, action: #selector(self.calledMethod(_:)), for: UIControlEvents.touchUpInside)
self.view.addSubview(btn)
}
}
This works absolutely fine but I was just wondering is there another way to detect when something is clicked and run some code when that happens.
You can add button in the storyboard and create an outlet for it's action.
#IBAction func buttonAction(_ sender: UIButton) {
//implement your code here
}
A button is a subclass of UIControl. A UIControl is designed to use target/action to specify code to run when the specified action occurs. If you don't want to use that mechanism, you have to create an equivalent.
You could attach a tap gesture recognizer to some other object and set it's userInteractionEnabled flag to true, but gesture recognizers ALSO use the target/action pattern.
My suggestion is to "stop worrying and learn to love the button." Just learn to use target/action.
Another possibility: Create a custom subclass of UIButton that sets itself up as it's own target at init time (specifically in init(coder:) and init(frame:), the 2 init methods you need to implement for view objects.) This button would include an array of closures that its action method would execute if the button was tapped. It would have methods to add or remove closures. You'd then put such a button in your view controller and call the method to add the closure you want.
You can also have a look at RxSwift/RxCocoa or similar. All the changes and actions are added automatically and you can decide if you want to observe them or not.
The code would look something like this:
let btn = UIButton(frame: CGRect(x: 30, y: 30, width: 60, height: 30))
btn.backgroundColor = UIColor.darkGray
btn
.rx
.tap
.subscribe(onNext: {
print("Clicked")
}).disposed(by: disposeBag)
view.addSubview(btn)
Goal
I want to make a custom keyboard that is only used within my app, not a system keyboard that needs to be installed.
What I have read and tried
Documentation
App Extension Programming Guide: Custom Keyboard
Custom Views for Data Input
The first article above states:
Make sure a custom, systemwide keyboard is indeed what you want to
develop. To provide a fully custom keyboard for just your app or to
supplement the system keyboard with custom keys in just your app, the
iOS SDK provides other, better options. Read about custom input views
and input accessory views in Custom Views for Data Input in Text
Programming Guide for iOS.
That is what led me to the second article above. However, that article did not have enough detail to get me started.
Tutorials
iOS 8: Creating a Custom Keyboard in Swift
How to make a custom keyboard in iOS 8 using Swift
Xcode 6 Tutorial: iOS 8.0 Simple Custom Keyboard in Swift
Creating a Custom Keyboard Using iOS 8 App Extension
I was able to get a working keyboard from the second tutorial in the list above. However, I couldn't find any tutorials that showed how to make an in app only keyboard as described in the Custom Views for Data Input documentation.
Stack Overflow
I also asked (and answered) these questions on my way to answering the current question.
How to input text using the buttons of an in-app custom keyboard
Delegates in Swift
Question
Does anyone have a minimal example (with even one button) of an in app custom keyboard? I am not looking for a whole tutorial, just a proof of concept that I can expand on myself.
This is a basic in-app keyboard. The same method could be used to make just about any keyboard layout. Here are the main things that need to be done:
Create the keyboard layout in an .xib file, whose owner is a .swift file that contains a UIView subclass.
Tell the UITextField to use the custom keyboard.
Use a delegate to communicate between the keyboard and the main view controller.
Create the .xib keyboard layout file
In Xcode go to File > New > File... > iOS > User Interface > View to create the .xib file.
I called mine Keyboard.xib
Add the buttons that you need.
Use auto layout constraints so that no matter what size the keyboard is, the buttons will resize accordingly.
Set the File's Owner (not the root view) to be the Keyboard.swift file. This is a common source of error. See the note at the end.
Create the .swift UIView subclass keyboard file
In Xcode go to File > New > File... > iOS > Source > Cocoa Touch Class to create the .swift file.
I called mine Keyboard.swift
Add the following code:
import UIKit
// The view controller will adopt this protocol (delegate)
// and thus must contain the keyWasTapped method
protocol KeyboardDelegate: class {
func keyWasTapped(character: String)
}
class Keyboard: UIView {
// This variable will be set as the view controller so that
// the keyboard can send messages to the view controller.
weak var delegate: KeyboardDelegate?
// MARK:- keyboard initialization
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
initializeSubviews()
}
override init(frame: CGRect) {
super.init(frame: frame)
initializeSubviews()
}
func initializeSubviews() {
let xibFileName = "Keyboard" // xib extention not included
let view = Bundle.main.loadNibNamed(xibFileName, owner: self, options: nil)![0] as! UIView
self.addSubview(view)
view.frame = self.bounds
}
// MARK:- Button actions from .xib file
#IBAction func keyTapped(sender: UIButton) {
// When a button is tapped, send that information to the
// delegate (ie, the view controller)
self.delegate?.keyWasTapped(character: sender.titleLabel!.text!) // could alternatively send a tag value
}
}
Control drag from the buttons in the .xib file to the #IBAction method in the .swift file to hook them all up.
Note that the protocol and delegate code. See this answer for a simple explanation about how delegates work.
Set up the View Controller
Add a UITextField to your main storyboard and connect it to your view controller with an IBOutlet. Call it textField.
Use the following code for the View Controller:
import UIKit
class ViewController: UIViewController, KeyboardDelegate {
#IBOutlet weak var textField: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
// initialize custom keyboard
let keyboardView = Keyboard(frame: CGRect(x: 0, y: 0, width: 0, height: 300))
keyboardView.delegate = self // the view controller will be notified by the keyboard whenever a key is tapped
// replace system keyboard with custom keyboard
textField.inputView = keyboardView
}
// required method for keyboard delegate protocol
func keyWasTapped(character: String) {
textField.insertText(character)
}
}
Note that the view controller adopts the KeyboardDelegate protocol that we defined above.
Common error
If you are getting an EXC_BAD_ACCESS error, it is probably because you set the view's custom class as Keyboard.swift rather than do this for the nib File's Owner.
Select Keyboard.nib and then choose File's Owner.
Make sure that the custom class for the root view is blank.
The key is to use the existing UIKeyInput protocol, to which UITextField already conforms. Then your keyboard view need only to send insertText() and deleteBackward() to the control.
The following example creates a custom numeric keyboard:
class DigitButton: UIButton {
var digit: Int = 0
}
class NumericKeyboard: UIView {
weak var target: (UIKeyInput & UITextInput)?
var useDecimalSeparator: Bool
var numericButtons: [DigitButton] = (0...9).map {
let button = DigitButton(type: .system)
button.digit = $0
button.setTitle("\($0)", for: .normal)
button.titleLabel?.font = .preferredFont(forTextStyle: .largeTitle)
button.setTitleColor(.black, for: .normal)
button.layer.borderWidth = 0.5
button.layer.borderColor = UIColor.darkGray.cgColor
button.accessibilityTraits = [.keyboardKey]
button.addTarget(self, action: #selector(didTapDigitButton(_:)), for: .touchUpInside)
return button
}
var deleteButton: UIButton = {
let button = UIButton(type: .system)
button.setTitle("⌫", for: .normal)
button.titleLabel?.font = .preferredFont(forTextStyle: .largeTitle)
button.setTitleColor(.black, for: .normal)
button.layer.borderWidth = 0.5
button.layer.borderColor = UIColor.darkGray.cgColor
button.accessibilityTraits = [.keyboardKey]
button.accessibilityLabel = "Delete"
button.addTarget(self, action: #selector(didTapDeleteButton(_:)), for: .touchUpInside)
return button
}()
lazy var decimalButton: UIButton = {
let button = UIButton(type: .system)
let decimalSeparator = Locale.current.decimalSeparator ?? "."
button.setTitle(decimalSeparator, for: .normal)
button.titleLabel?.font = .preferredFont(forTextStyle: .largeTitle)
button.setTitleColor(.black, for: .normal)
button.layer.borderWidth = 0.5
button.layer.borderColor = UIColor.darkGray.cgColor
button.accessibilityTraits = [.keyboardKey]
button.accessibilityLabel = decimalSeparator
button.addTarget(self, action: #selector(didTapDecimalButton(_:)), for: .touchUpInside)
return button
}()
init(target: UIKeyInput & UITextInput, useDecimalSeparator: Bool = false) {
self.target = target
self.useDecimalSeparator = useDecimalSeparator
super.init(frame: .zero)
configure()
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
// MARK: - Actions
extension NumericKeyboard {
#objc func didTapDigitButton(_ sender: DigitButton) {
insertText("\(sender.digit)")
}
#objc func didTapDecimalButton(_ sender: DigitButton) {
insertText(Locale.current.decimalSeparator ?? ".")
}
#objc func didTapDeleteButton(_ sender: DigitButton) {
target?.deleteBackward()
}
}
// MARK: - Private initial configuration methods
private extension NumericKeyboard {
func configure() {
autoresizingMask = [.flexibleWidth, .flexibleHeight]
addButtons()
}
func addButtons() {
let stackView = createStackView(axis: .vertical)
stackView.frame = bounds
stackView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
addSubview(stackView)
for row in 0 ..< 3 {
let subStackView = createStackView(axis: .horizontal)
stackView.addArrangedSubview(subStackView)
for column in 0 ..< 3 {
subStackView.addArrangedSubview(numericButtons[row * 3 + column + 1])
}
}
let subStackView = createStackView(axis: .horizontal)
stackView.addArrangedSubview(subStackView)
if useDecimalSeparator {
subStackView.addArrangedSubview(decimalButton)
} else {
let blank = UIView()
blank.layer.borderWidth = 0.5
blank.layer.borderColor = UIColor.darkGray.cgColor
subStackView.addArrangedSubview(blank)
}
subStackView.addArrangedSubview(numericButtons[0])
subStackView.addArrangedSubview(deleteButton)
}
func createStackView(axis: NSLayoutConstraint.Axis) -> UIStackView {
let stackView = UIStackView()
stackView.axis = axis
stackView.alignment = .fill
stackView.distribution = .fillEqually
return stackView
}
func insertText(_ string: String) {
guard let range = target?.selectedRange else { return }
if let textField = target as? UITextField, textField.delegate?.textField?(textField, shouldChangeCharactersIn: range, replacementString: string) == false {
return
}
if let textView = target as? UITextView, textView.delegate?.textView?(textView, shouldChangeTextIn: range, replacementText: string) == false {
return
}
target?.insertText(string)
}
}
// MARK: - UITextInput extension
extension UITextInput {
var selectedRange: NSRange? {
guard let textRange = selectedTextRange else { return nil }
let location = offset(from: beginningOfDocument, to: textRange.start)
let length = offset(from: textRange.start, to: textRange.end)
return NSRange(location: location, length: length)
}
}
Then you can:
textField.inputView = NumericKeyboard(target: textField)
That yields:
Or, if you want a decimal separator, too, you can:
textField.inputView = NumericKeyboard(target: textField, useDecimalSeparator: true)
The above is fairly primitive, but it illustrates the idea: Make you own input view and use the UIKeyInput protocol to communicate keyboard input to the control.
Also please note the use of accessibilityTraits to get the correct “Spoken Content” » “Speak Screen” behavior. And if you use images for your buttons, make sure to set accessibilityLabel, too.
Building on Suragch's answer, I needed a done and backspace button and if you're a noob like me heres some errors you might encounter and the way I solved them.
Getting EXC_BAD_ACCESS errors?
I included:
#objc(classname)
class classname: UIView{
}
fixed my issue however Suragch's updated answer seems to solve this the more appropriate/correct way.
Getting SIGABRT Error?
Another silly thing was dragging the connections the wrong way, causing SIGABRT error. Do not drag from the function to the button but instead the button to the function.
Adding a Done Button
I added this to the protocol in keyboard.swift:
protocol KeyboardDelegate: class {
func keyWasTapped(character: String)
func keyDone()
}
Then connected a new IBAction from my done button to keyboard.swift like so:
#IBAction func Done(sender: UIButton) {
self.delegate?.keyDone()
}
and then jumped back to my viewController.swift where i am using this keyboard and added this following after the function keyWasTapped:
func keyDone() {
view.endEditing(true)
}
Adding Backspace
This tripped me up a lot, because you must set the textField.delegate to self in the viewDidLoad() method (shown later).
First: In keyboard.swift add to the protocol func backspace():
protocol KeyboardDelegate: class {
func keyWasTapped(character: String)
func keyDone()
func backspace()
}
Second: Connect a new IBAction similar to the Done action:
#IBAction func backspace(sender: UIButton) {
self.delegate?.backspace()
}
Third: Over to the viewController.swift where the NumberPad is appearing.
Important: In viewDidLoad() set all textFields that will be using this keyboard. So your viewDidLoad() should look something like this:
override func viewDidLoad() {
super.viewDidLoad()
self.myTextField1.delegate = self
self.myTextField2.delegate = self
// initialize custom keyboard
let keyboardView = keyboard(frame: CGRect(x: 0, y: 0, width: 0, height: 240))
keyboardView.delegate = self // the view controller will be notified by the keyboard whenever a key is tapped
// replace system keyboard with custom keyboard
myTextField1.inputView = keyboardView
myTextField2.inputView = keyboardView
}
I'm not sure how to, if there is a way to just do this to all textFields that are in the view. This would be handy...
Forth: Still in viewController.swift we need to add a variable and two functions. It will look like this:
var activeTextField = UITextField()
func textFieldDidBeginEditing(textField: UITextField) {
print("Setting Active Textfield")
self.activeTextField = textField
print("Active textField Set!")
}
func backspace() {
print("backspaced!")
activeTextField.deleteBackward()
}
Explanation of whats happening here:
You make a variable that will hold a textField.
When the "textFieldDidBeginEditing" is called it sets the variable so it knows which textField we are dealing with. I've added a lot of prints() so we know everything is being executed.
Our backspace function then checks the textField we are dealing with and uses .deleteBackward(). This removes the immediate character before the cursor.
And you should be in business.
Many thanks to Suragchs for helping me get this happening.
When I first run my app, I retrieve a number from my server and display it for my UIButton label. Think of this as a notification number displayed on a red UIButton.
When I remove a notification within the app, I want my UIButton label decrement by 1. I am able to get the decremented number from the server after I delete a notification, but I can't display this new number on the UIButton. The button always displays the number when the app is first fired.
I call makeButtonView() method after I remove a notification to update the UIButton
func makeButtonView(){
var button = makeButton()
view.addSubView(button)
button.tag = 2
if (view.viewWithTag(2) != nil) {
view.viewWithTag(2)?.removeFromSuperview()
var updatedButton = makeButton()
view.addSubview(updatedButton)
}else{
println("No button found with tag 2")
}
}
func makeButton() -> UIButton{
let button = UIButton(frame: CGRectMake(50, 5, 60, 40))
button.setBackgroundImage(UIImage(named: "redBubbleButton"), forState: .Normal)
API.getNotificationCount(userID) {
data, error in
button.setTitle("\(data)", forState: UIControlState.Normal)
}
button.addTarget(self, action: "targetController:", forControlEvents: UIControlEvents.TouchUpInside)
return button
}
Use this code for Swift 4 or 5
button.setTitle("Click Me", for: .normal)
I need more information to give you a proper code. But this approach should work:
lazy var button : UIButton = {
let button = UIButton(frame: CGRectMake(50, 5, 60, 40))
button.setBackgroundImage(UIImage(named: "redBubbleButton"), forState: .Normal)
button.addTarget(self, action: "targetController:", forControlEvents: UIControlEvents.TouchUpInside)
return button
}()
func makeButtonView(){
// This should be called just once!!
// Likely you should call this method from viewDidLoad()
self.view.addSubview(button)
}
func updateButton(){
API.getNotificationCount(userID) {
data, error in
// be sure this is call in the main thread!!
button.setTitle("\(data)", forState: UIControlState.Normal)
}
}
There have been some updates since Swift 4. This works for me:
self.button.setTitle("Button Title", for: UIControl.State.init(rawValue: 0))
Replace button with your IBOutlet name. You can also use a variable or array in place of the quoted text.
It's fairly simple ...
import UIKit
class ViewController: UIViewController {
#IBOutlet var button: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
button.setTitle("hello world", forState: UIControlState.Normal)
}
}
I believe if you set the state to normal, the value will propagate by default to other states so long as you haven't explicitly set a title for those states.
Said differently, if you set it for normal, it should also display this title when the button enters additional states
UIControlState.allZeros
UIControlState.Application
UIControlState.Disabled
UIControlState.Highlighted
UIControlState.Reserved
UIControlState.Selected
Lastly, here's Apple's documentation in case you have other questions.
Since your API call should be running on a background thread you need to dispatch your UI update back to the main thread like this:
DispatchQueue.main.async {
button.setTitle(“new value”, forState: .normal)
}
After setting the title, just a simple redraw of the button will do:
button.setNeedsDisplay();
I am trying to create a custom drop down list in a ViewController. There are going to be 5 drop down lists and each list will have 4 options. Because of the number of lists, I decided to make a UIView that has the four choices in the form of UIButtons for each of the lists. Right now I am just trying to get one down; therefore, the following code is for ONE drop down list with FIVE options (including the one selected, which I will explain further below).
Essentially what I want is to have a button showing the selected value (or a default value at launch) and then when you click on that value then the UIView that contains 4 buttons (aka the drop down list) is shown below the original button. When the user clicks on one of the buttons I want the the button with the selected value to have the title of the button that was clicked on.
I am having the following issues:
I want to be able to pass the titles of the four buttons from the ViewController to the UIView because I want to use this UIView multiple times with different values for the titles of the four buttons. I don't know how to pass values to a UIView class.
When a choice from the drop down list (ie a UIButton) is clicked I can't figure out how to pass the value of the title of the button from the UIView back to UIViewController. I tried setting the title to a variable in the ViewController but that didn't work (showed up as nil).
Thank you so much in advance - I know this is a long questions and I am really unsure if this is even a good approach to take for what I am trying to do but it made sense in my head.
Here is my code for the ViewController
var buttonsLeft: buttonsView = buttonsView() // this is the UIView subclass
var time = UIButton.buttonWithType(UIButtonType.System) as! UIButton
override func viewWillAppear(animated: Bool) {
//hidden drop down list
self.buttonsLeft.frame = CGRect(x: self.view.bounds.width*(1/6) - 50, y:120, width:100, height: 135)
self.buttonsLeft.hidden = true
//button with selection showing or the default value at launch
self.time.frame = CGRectMake(self.view.bounds.width * (1/6) - 50, 90, 100, 30)
self.time.setTitle("1 DAY", forState: UIControlState.Normal)
self.time.addTarget(self, action: "showLeft", forControlEvents: UIControlEvents.TouchUpInside)
self.time.hidden = false
self.view.addSubview(self.time)
}
//this function shows the list
func showLeft(){
self.view.addSubview(self.buttonsLeft)
self.buttonsLeft.hidden = false
}
Here is the code for the UIView buttonsView:
import UIKit
class buttonsView: UIView {
var option1 = UIButton()
var option2 = UIButton()
var option3 = UIButton()
var option4 = UIButton()
var buttons: Array<UIButton> = Array()
var title:String = String()
override init(frame: CGRect) {
super.init(frame: frame)
self.buttons = [option1, option2, option3, option4]
self.option1.setTitle("1 DAY", forState: UIControlState.Normal)
self.option2.setTitle("1 MONTH", forState: UIControlState.Normal)
self.option3.setTitle("1 YEAR", forState: UIControlState.Normal)
self.option4.setTitle("LONGER", forState: UIControlState.Normal)
var yStep = 35
for var i:Int = 0; i < 4; ++i {
var totalY:CGFloat = CGFloat(i*yStep)
buttons[i].frame = CGRectMake(0, totalY, 100, 30)
buttons[i].addTarget(self, action: "choseOption:", forControlEvents: UIControlEvents.TouchUpInside)
buttons[i].hidden = false
self.addSubview(buttons[i])
}
}
func choseOption(sender:UIButton){
self.title = sender.titleLabel!.text!
MyView().parentTitle = sender.titleLabel!.text! // my attempt at assigning to variable in View Controller
}
required init(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
Delegation will help you to pass value to UIViewController.
Here are the way you can implement delegate in swift.
Step 1 : Declare protocol in class which is used to sending data. here is buttonsview.
#objc protocol MyButtonDelegate{
optional func didSelectButton(text:String)
}
Step 2 : Now declare delegate in sending class. here is buttonsview.
class buttonsView: UIView {
var delegate:MyButtonDelegate?
[other stuf......]
}
Step 3: now use delegate to send data to 'UIViewController'.
func choseOption(sender:UIButton){
delegate!.didSelectButton(text: sender.titleLabel!.text!)
}
Step 4 : adopt protocol in receiving class.
class ViewController: UIViewController,MyButtonDelegate {
Step 5: implement delegate method in receiving class.
func didSelectButton(text: String) {
parentTitle = "The Buttons title is " + text
}
Step 6: now set delegate
override func viewDidLoad() {
super.viewDidLoad()
buttonsLeft.delegate = self
}
Hope this help you.