This question already has answers here:
How to show UIAlertController from Appdelegate
(6 answers)
Closed 4 years ago.
I try the next code snippet:
var alert = UIAlertController(title: "Alert", message: "Cannot connect to : \(error!.localizedDescription)", preferredStyle: UIAlertControllerStyle.Alert)
alert.addAction(UIAlertAction(title: "Click", style: UIAlertActionStyle.Default, handler: nil))
self.window?.rootViewController?.presentViewController(alert, animated: true, completion: nil)
in my AppDelegate, but it prints me the next error in console:
Warning: Attempt to present <UIAlertController: 0x7ff6cd827a30> on <Messenger.WelcomeController: 0x7ff6cb51c940> whose view is not in the window hierarchy!
How can I fix this error?
This is what i'm using now to do that.
var alertController = UIAlertController(title: "Title", message: "Any message", preferredStyle: .ActionSheet)
var okAction = UIAlertAction(title: "Yes", style: UIAlertActionStyle.Default) {
UIAlertAction in
NSLog("OK Pressed")
}
var cancelAction = UIAlertAction(title: "No", style: UIAlertActionStyle.Cancel) {
UIAlertAction in
NSLog("Cancel Pressed")
}
alertController.addAction(okAction)
alertController.addAction(cancelAction)
self.window?.rootViewController?.presentViewController(alertController, animated: true, completion: nil)
Swift 5:
let alert = UIAlertController(title: "Test", message:"Message", preferredStyle: UIAlertController.Style.alert)
// add an action (button)
alert.addAction(UIAlertAction(title: "OK", style: UIAlertAction.Style.default, handler: nil))
// show the alert
self.window?.rootViewController?.present(alert, animated: true, completion: nil)
As per Jorge's answer, updated for Swift 4
let alertController = UIAlertController(title: "Title", message: "Message", preferredStyle: .actionSheet)
let okAction = UIAlertAction(title: "OK", style: UIAlertActionStyle.default) {
UIAlertAction in
NSLog("OK Pressed")
}
let cancelAction = UIAlertAction(title: "CANCEL", style: UIAlertActionStyle.cancel) {
UIAlertAction in
NSLog("Cancel Pressed")
}
alertController.addAction(okAction)
alertController.addAction(cancelAction)
self.window?.rootViewController?.present(alertController, animated: true, completion: nil)
Swift 3.0 or above, Working in all condition , like in case of tab bar, in case of presented view etc ..
let alert = UIAlertController(title: "Test", message:"Message", preferredStyle: UIAlertControllerStyle.alert)
// add an action (button)
alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: nil))
// show alert
let alertWindow = UIWindow(frame: UIScreen.main.bounds)
alertWindow.rootViewController = UIViewController()
alertWindow.windowLevel = UIWindowLevelAlert + 1;
alertWindow.makeKeyAndVisible()
alertWindow.rootViewController?.present(alertController, animated: true, completion: nil)
I had the similar problem.
I have fixed it by presenting UIAlertController in Main Queue.
Code Looks like following.
let alert = UIAlertController(title: "My Title", message: "My Message", preferredStyle: .alert)
let actionYes = UIAlertAction(title: "Yes", style: .default, handler: { action in
print("action yes handler")
})
let actionCancel = UIAlertAction(title: "Cancel", style: .destructive, handler: { action in
print("action cancel handler")
})
alert.addAction(actionYes)
alert.addAction(actionCancel)
DispatchQueue.main.async {
self.window?.rootViewController?.present(alert, animated: true, completion: nil)
}
Have you tried using UIApplication.shared.keyWindow?.rootViewController?.present(...) ?
I suppose you are calling that code snippet from the applicationDidFinishLunchingWithOptions.
I tried it as a matter of fact because I had to. The thing is: what you are trying to do is correct but the ViewController that the AppDelegate makes and presents is about to be put on screen and before that, the code snippet tries to create an alertView and put in on top of non existent View of the RootViewController.
What I would do is move it to another delegate call which is guaranteed to be called after the RootViewController is presented.
func applicationDidBecomeActive(application: UIApplication) {
//This method is called when the rootViewController is set and the view.
// And the View controller is ready to get touches or events.
var alert = UIAlertController(title: "Alert", message: "Cannot connect to :", preferredStyle: UIAlertControllerStyle.Alert)
alert.addAction(UIAlertAction(title: "Click", style: UIAlertActionStyle.Default, handler: nil))
self.window?.rootViewController?.presentViewController(alert, animated: true, completion: nil)
}
But as always know the responsibility of the AppDelegate. It is to handle the application lifecycle and application wide delegate calls and events. If putting code here makes sense, then do it. But if you will be better off putting the code on the rootViewController or other parts then think about it too.
Anyway, hope it helps. Cheers!
I would suggest NOT doing this in the AppDelegate. The App Delegate it intended to handle Delegate functions from the OS rather than implementing things like alert views.
If you are wanting to present an alert view here to be shown at the start of the app I would do this by implementing it in your first view controller.
I have been working to create a UIAlertView in Swift, but for some reason I can't get the statement right because I'm getting this error:
Could not find an overload for 'init' that accepts the supplied
arguments
Here is how I have it written:
let button2Alert: UIAlertView = UIAlertView(title: "Title", message: "message",
delegate: self, cancelButtonTitle: "OK", otherButtonTitles: nil)
Then to call it I'm using:
button2Alert.show()
As of right now it is crashing and I just can't seem to get the syntax right.
From the UIAlertView class:
// UIAlertView is deprecated. Use UIAlertController with a
preferredStyle of UIAlertControllerStyleAlert instead
On iOS 8, you can do this:
let alert = UIAlertController(title: "Alert", message: "Message", preferredStyle: UIAlertControllerStyle.Alert)
alert.addAction(UIAlertAction(title: "Click", style: UIAlertActionStyle.Default, handler: nil))
self.presentViewController(alert, animated: true, completion: nil)
Now UIAlertController is a single class for creating and interacting with what we knew as UIAlertViews and UIActionSheets on iOS 8.
Edit: To handle actions:
alert.addAction(UIAlertAction(title: "OK", style: .Default, handler: { action in
switch action.style{
case .Default:
print("default")
case .Cancel:
print("cancel")
case .Destructive:
print("destructive")
}
}}))
Edit for Swift 3:
let alert = UIAlertController(title: "Alert", message: "Message", preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "Click", style: UIAlertActionStyle.default, handler: nil))
self.present(alert, animated: true, completion: nil)
Edit for Swift 4.x:
let alert = UIAlertController(title: "Alert", message: "Message", preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "OK", style: .default, handler: { action in
switch action.style{
case .default:
print("default")
case .cancel:
print("cancel")
case .destructive:
print("destructive")
}
}))
self.present(alert, animated: true, completion: nil)
One Button
class ViewController: UIViewController {
#IBAction func showAlertButtonTapped(_ sender: UIButton) {
// create the alert
let alert = UIAlertController(title: "My Title", message: "This is my message.", preferredStyle: UIAlertController.Style.alert)
// add an action (button)
alert.addAction(UIAlertAction(title: "OK", style: UIAlertAction.Style.default, handler: nil))
// show the alert
self.present(alert, animated: true, completion: nil)
}
}
Two Buttons
class ViewController: UIViewController {
#IBAction func showAlertButtonTapped(_ sender: UIButton) {
// create the alert
let alert = UIAlertController(title: "UIAlertController", message: "Would you like to continue learning how to use iOS alerts?", preferredStyle: UIAlertController.Style.alert)
// add the actions (buttons)
alert.addAction(UIAlertAction(title: "Continue", style: UIAlertAction.Style.default, handler: nil))
alert.addAction(UIAlertAction(title: "Cancel", style: UIAlertAction.Style.cancel, handler: nil))
// show the alert
self.present(alert, animated: true, completion: nil)
}
}
Three Buttons
class ViewController: UIViewController {
#IBAction func showAlertButtonTapped(_ sender: UIButton) {
// create the alert
let alert = UIAlertController(title: "Notice", message: "Lauching this missile will destroy the entire universe. Is this what you intended to do?", preferredStyle: UIAlertController.Style.alert)
// add the actions (buttons)
alert.addAction(UIAlertAction(title: "Remind Me Tomorrow", style: UIAlertAction.Style.default, handler: nil))
alert.addAction(UIAlertAction(title: "Cancel", style: UIAlertAction.Style.cancel, handler: nil))
alert.addAction(UIAlertAction(title: "Launch the Missile", style: UIAlertAction.Style.destructive, handler: nil))
// show the alert
self.present(alert, animated: true, completion: nil)
}
}
Handling Button Taps
The handler was nil in the above examples. You can replace nil with a closure to do something when the user taps a button. For example:
alert.addAction(UIAlertAction(title: "Launch the Missile", style: UIAlertAction.Style.destructive, handler: { action in
// do something like...
self.launchMissile()
}))
Notes
Multiple buttons do not necessarily need to use different UIAlertAction.Style types. They could all be .default.
For more than three buttons consider using an Action Sheet. The setup is very similar. Here is an example.
You can create a UIAlert using the standard constructor, but the 'legacy' one seems to not work:
let alert = UIAlertView()
alert.title = "Alert"
alert.message = "Here's a message"
alert.addButtonWithTitle("Understood")
alert.show()
In Swift 4.2 and Xcode 10
Method 1 :
SIMPLE ALERT
let alert = UIAlertController(title: "Your title", message: "Your message", preferredStyle: .alert)
let ok = UIAlertAction(title: "OK", style: .default, handler: { action in
})
alert.addAction(ok)
let cancel = UIAlertAction(title: "Cancel", style: .default, handler: { action in
})
alert.addAction(cancel)
DispatchQueue.main.async(execute: {
self.present(alert, animated: true)
})
Method 2 :
ALERT WITH SHARED CLASS
If you want Shared class style(Write once use every where)
import UIKit
class SharedClass: NSObject {//This is shared class
static let sharedInstance = SharedClass()
//Show alert
func alert(view: UIViewController, title: String, message: String) {
let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
let defaultAction = UIAlertAction(title: "OK", style: .default, handler: { action in
})
alert.addAction(defaultAction)
DispatchQueue.main.async(execute: {
view.present(alert, animated: true)
})
}
private override init() {
}
}
Now call alert like this in every ware
SharedClass.sharedInstance.alert(view: self, title: "Your title here", message: "Your message here")
Method 3 :
PRESENT ALERT TOP OF ALL WINDOWS
If you want to present alert on top of all views, use this code
func alertWindow(title: String, message: String) {
DispatchQueue.main.async(execute: {
let alertWindow = UIWindow(frame: UIScreen.main.bounds)
alertWindow.rootViewController = UIViewController()
alertWindow.windowLevel = UIWindowLevelAlert + 1
let alert2 = UIAlertController(title: title, message: message, preferredStyle: .alert)
let defaultAction2 = UIAlertAction(title: "OK", style: .default, handler: { action in
})
alert2.addAction(defaultAction2)
alertWindow.makeKeyAndVisible()
alertWindow.rootViewController?.present(alert2, animated: true, completion: nil)
})
}
Function calling
SharedClass.sharedInstance.alertWindow(title:"This your title", message:"This is your message")
Method 4 :
Alert with Extension
extension UIViewController {
func showAlert(withTitle title: String, withMessage message:String) {
let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
let ok = UIAlertAction(title: "OK", style: .default, handler: { action in
})
let cancel = UIAlertAction(title: "Cancel", style: .default, handler: { action in
})
alert.addAction(ok)
alert.addAction(cancel)
DispatchQueue.main.async(execute: {
self.present(alert, animated: true)
})
}
}
Now call like this
//Call showAlert function in your class
#IBAction func onClickAlert(_ sender: UIButton) {
showAlert(withTitle:"Your Title Here", withMessage: "YourCustomMessageHere")
}
Method 5 :
ALERT WITH TEXTFIELDS
If you want to add textfields to alert.
//Global variables
var name:String?
var login:String?
//Call this function like this: alertWithTF()
//Add textfields to alert
func alertWithTF() {
let alert = UIAlertController(title: "Login", message: "Enter username&password", preferredStyle: .alert)
// Login button
let loginAction = UIAlertAction(title: "Login", style: .default, handler: { (action) -> Void in
// Get TextFields text
let usernameTxt = alert.textFields![0]
let passwordTxt = alert.textFields![1]
//Asign textfileds text to our global varibles
self.name = usernameTxt.text
self.login = passwordTxt.text
print("USERNAME: \(self.name!)\nPASSWORD: \(self.login!)")
})
// Cancel button
let cancel = UIAlertAction(title: "Cancel", style: .destructive, handler: { (action) -> Void in })
//1 textField for username
alert.addTextField { (textField: UITextField) in
textField.placeholder = "Enter username"
//If required mention keyboard type, delegates, text sixe and font etc...
//EX:
textField.keyboardType = .default
}
//2nd textField for password
alert.addTextField { (textField: UITextField) in
textField.placeholder = "Enter password"
textField.isSecureTextEntry = true
}
// Add actions
alert.addAction(loginAction)
alert.addAction(cancel)
self.present(alert, animated: true, completion: nil)
}
Method 6:
Alert in SharedClass with Extension
//This is your shared class
import UIKit
class SharedClass: NSObject {
static let sharedInstance = SharedClass()
//Here write your code....
private override init() {
}
}
//Alert function in shared class
extension UIViewController {
func showAlert(title: String, msg: String) {
DispatchQueue.main.async {
let alert = UIAlertController(title: title, message: msg, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
self.present(alert, animated: true, completion: nil)
}
}
}
Now call directly like this
self.showAlert(title: "Your title here...", msg: "Your message here...")
Method 7:
Alert with out shared class with Extension in separate class for alert.
Create one new Swift class, and import UIKit. Copy and paste below code.
//This is your Swift new class file
import UIKit
import Foundation
extension UIAlertController {
class func alert(title:String, msg:String, target: UIViewController) {
let alert = UIAlertController(title: title, message: msg, preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "Ok", style: UIAlertActionStyle.default) {
(result: UIAlertAction) -> Void in
})
target.present(alert, animated: true, completion: nil)
}
}
Now call alert function like this in all your classes (Single line).
UIAlertController.alert(title:"Title", msg:"Message", target: self)
How is it....
Click of View
#IBAction func testClick(sender: UIButton) {
var uiAlert = UIAlertController(title: "Title", message: "Message", preferredStyle: UIAlertControllerStyle.Alert)
self.presentViewController(uiAlert, animated: true, completion: nil)
uiAlert.addAction(UIAlertAction(title: "Ok", style: .Default, handler: { action in
println("Click of default button")
}))
uiAlert.addAction(UIAlertAction(title: "Cancel", style: .Cancel, handler: { action in
println("Click of cancel button")
}))
}
Done with two buttons OK & Cancel
If you're targeting iOS 7 and 8, you need something like this to make sure you're using the right method for each version, because UIAlertView is deprecated in iOS 8, but UIAlertController is not available in iOS 7:
func alert(title: String, message: String) {
if let getModernAlert: AnyClass = NSClassFromString("UIAlertController") { // iOS 8
let myAlert: UIAlertController = UIAlertController(title: title, message: message, preferredStyle: .Alert)
myAlert.addAction(UIAlertAction(title: "OK", style: .Default, handler: nil))
self.presentViewController(myAlert, animated: true, completion: nil)
} else { // iOS 7
let alert: UIAlertView = UIAlertView()
alert.delegate = self
alert.title = title
alert.message = message
alert.addButtonWithTitle("OK")
alert.show()
}
}
With the protocol extensions of Swift 2, you can make a protocol that provides a default implementation to your view controllers:
ShowsAlert.swift
import UIKit
protocol ShowsAlert {}
extension ShowsAlert where Self: UIViewController {
func showAlert(title: String = "Error", message: String) {
let alertController = UIAlertController(title: title, message: message, preferredStyle: .Alert)
alertController.addAction(UIAlertAction(title: "Ok", style: .Default, handler: nil))
presentViewController(alertController, animated: true, completion: nil)
}
}
ViewController.swift
class ViewController: UIViewController, ShowsAlert {
override func viewDidLoad() {
super.viewDidLoad()
showAlert(message: "Hey there, I am an error message!")
}
}
Show UIAlertView in swift language :-
Protocol UIAlertViewDelegate
let alert = UIAlertView(title: "alertView", message: "This is alertView", delegate:self, cancelButtonTitle:"Cancel", otherButtonTitles: "Done", "Delete")
alert.show()
Show UIAlertViewController in swift language :-
let alert = UIAlertController(title: "Error", message: "Enter data in Text fields", preferredStyle: UIAlertControllerStyle.Alert)
alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: nil))
self.presentViewController(alert, animated: true, completion: nil)
Simply do not provide otherButtonTitles in the constructor.
let alertView = UIAlertView(title: "Oops!", message: "Something
happened...", delegate: nil, cancelButtonTitle: "OK")
alertView.show()
But I do agree with Oscar, this class is deprecated in iOS 8, so there won't be no use of UIAlertView if you're doing an iOS 8 only app. Otherwise the code above will work.
For SWIFT4, I think, extending UIViewController and creating a reusable confirmation control is the most elegant way.
You can extend the UIViewController as below:
extension UIViewController {
func AskConfirmation (title:String, message:String, completion:#escaping (_ result:Bool) -> Void) {
let alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertControllerStyle.alert)
self.present(alert, animated: true, completion: nil)
alert.addAction(UIAlertAction(title: "Ok", style: .default, handler: { action in
completion(true)
}))
alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: { action in
completion(false)
}))
}
}
Then you can use it anytime:
AskConfirmation(title: "YOUR MESSAGE TITLE", message: "YOUR MESSAGE") { (result) in
if result { //User has clicked on Ok
} else { //User has clicked on Cancel
}
}
AlertView Swift 5 and above:-
let alert = UIAlertController(title: LocalizedStringConstant.alert, message: message, preferredStyle: UIAlertController.Style.alert)
alert.addAction(UIAlertAction(title: "Retry", style: .cancel, handler: { (_) in
}))
self.present(alert, animated: true, completion: nil)
I found this one,
var alertView = UIAlertView();
alertView.addButtonWithTitle("Ok");
alertView.title = "title";
alertView.message = "message";
alertView.show();
not good though, but it works :)
Update:
but I have found on header file as:
extension UIAlertView {
convenience init(title: String, message: String, delegate: UIAlertViewDelegate?, cancelButtonTitle: String?, otherButtonTitles firstButtonTitle: String, _ moreButtonTitles: String...)
}
somebody may can explain this.
For iOS 13 Xcode 11+ Swift 5.X
UIAlertController can now provide Alerts as well as Action Sheets
Alerts
// First instantiate the UIAlertController
let alert = UIAlertController(title: "Title",
message: "Message ?",
preferredStyle: .alert)
// Add action buttons to it and attach handler functions if you want to
alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
alert.addAction(UIAlertAction(title: "Just Do It!", style: .destructive, handler: nil))
alert.addAction(UIAlertAction(title: "Maybe", style: .default, handler: nil))
// Show the alert by presenting it
self.present(alert, animated: true)
Note that it's is a fundamental nature for all action buttons to dismiss the alert view when tapped. The style parameter is just for deciding the color of the text (and some default order in which the buttons should appear which ofc can be changed)
A sample handler function could be
func handler(_ action: UIAlertAction) {
if action.title == 'Title' {
// do stuff
}
}
As a side note, I would say instead of making 3 different handlers you can just make 1 and trace back to the element which provoked it in the manner shown above
We can also check alert.style but that again we can have multiple .default styled actions , I wouldn't recommend that
Action Sheets
The explanation is similar because the main difference here is that an alert interrupts the user whereas an action sheet slides from the bottom in an iPhone and appears as a popover in an iPad
The Purpose of action sheets is to guide the users in deciding his actions based on their current state. So you gotta treat action sheets like crossroads !. There is generally no message and the title is rendered as caption sized text
let action = UIAlertController(title: "What do you want to do with the message",
message: nil,
preferredStyle: .actionSheet)
action.addAction(UIAlertAction(title: "Cancel", style: .cancel))
for act in ["Save", "Post", "Discard"] {
action.addAction(UIAlertAction(title: act, style: .default, handler: nil))
}
self.present(action, animated: true)
The above code is going to work for an iPhone but will crash at runtime for an iPad because UIPopoverPresentationController is going to take charge of the alert and it won't be referencing anything at that time. So to avoid that you will have to provide the following chunk of code its mandatory
if let pop = action.popoverPresentationController {
let v = sender as! UIView
pop.sourceView = v
pop.sourceRect = v.bounds
}
Also in case of iPad tapping on anywhere outside the popover will dismiss it and the completion handler of .cancel action button will be called.
Hope that helps :) That being said, comment down below if you have any doubts
class Preview: UIViewController , UIAlertViewDelegate
{
#IBAction func MoreBtnClicked(sender: AnyObject)
{
var moreAlert=UIAlertView(title: "Photo", message: "", delegate: self, cancelButtonTitle: "No Thanks!", otherButtonTitles: "Save Image", "Email", "Facebook", "Whatsapp" )
moreAlert.show()
moreAlert.tag=111;
}
func alertView(alertView: UIAlertView, didDismissWithButtonIndex buttonIndex: Int)
{
if alertView.tag==111
{
if buttonIndex==0
{
println("No Thanks!")
}
else if buttonIndex==1
{
println("Save Image")
}
else if buttonIndex == 2
{
println("Email")
}
else if buttonIndex == 3
{
println("Facebook")
}
else if buttonIndex == 4
{
println("Whatsapp")
}
}
}
}
I have another trick. Suppose you have 5 classes where a logout alert to be applied. Try with swift class extension.
File- New- Swift class- Name it.
Add the following:
public extension UIViewController
{
func makeLogOutAlert()
{
var refreshAlert = UIAlertController(title: "Log Out", message: "Are You Sure to Log Out ? ", preferredStyle: UIAlertControllerStyle.Alert)
refreshAlert.addAction(UIAlertAction(title: "Confirm", style: .Default, handler: { (action: UIAlertAction!) in
self.navigationController?.popToRootViewControllerAnimated(true)
}))
refreshAlert.addAction(UIAlertAction(title: "Cancel", style: .Default, handler: { (action: UIAlertAction!) in
refreshAlert .dismissViewControllerAnimated(true, completion: nil)
}))
presentViewController(refreshAlert, animated: true, completion: nil)
}
}
Implement using : self.makeLogOutAlert(). Hope it helps.
I have made a singleton class to make this convenient to use from anywhere in your app: https://github.com/Swinny1989/Swift-Popups
You can then create a popup with multiple buttons like this:
Popups.SharedInstance.ShowAlert(self, title: "Title goes here", message: "Messages goes here", buttons: ["button one" , "button two"]) { (buttonPressed) -> Void in
if buttonPressed == "button one" {
//Code here
} else if buttonPressed == "button two" {
// Code here
}
}
or popups with a single button like this:
Popups.SharedInstance.ShowPopup("Title goes here", message: "Message goes here.")
Swift 3
The following is a simple example of how to create a simple alert with one button with Swift 3.
let alert = UIAlertController(title: "Title",
message: "Message",
preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "Ok", style: .default))
present(alert, animated: true)
In the above example the handle callback of the action has been omitted because the default behaviour of an alert view with one button is to disappear when the button is clicked.
Here is how to create another action, which could be added to the alert with "alert.addAction(action)". The different styles are .default, .destructive and .cancel.
let action = UIAlertAction(title: "Ok", style: .default) { action in
// Handle when button is clicked
}
I got the following UIAlertView initialization code to compile without errors (I thing the last, varyadic part is tricky perhaps). But I had to make sure the class of self (which I am passing as the delegate) was adopting the UIAlertViewDelegate protocol for the compile errors to go away:
let alertView = UIAlertView(
title: "My Title",
message: "My Message",
delegate: self,
cancelButtonTitle: "Cancel",
otherButtonTitles: "OK"
)
By the way, this is the error I was getting (as of Xcode 6.4):
Cannot find an initializer for type 'UIAlertView' that accepts an
argument list of type '(title: String, message: String, delegate:
MyViewController, cancelButtonTitle: String, otherButtonTitles:
String)'
As others mentioned, you should migrate to UIAlertController if you can target iOS 8.x+. To support iOS 7, use the code above (iOS 6 is not supported by Swift).
let alertController = UIAlertController(title: "Select Photo", message: "Select atleast one photo", preferredStyle: .alert)
let action1 = UIAlertAction(title: "From Photo", style: .default) { (action) in
print("Default is pressed.....")
}
let action2 = UIAlertAction(title: "Cancel", style: .cancel) { (action) in
print("Cancel is pressed......")
}
let action3 = UIAlertAction(title: "Click new", style: .default) { (action) in
print("Destructive is pressed....")
}
alertController.addAction(action1)
alertController.addAction(action2)
alertController.addAction(action3)
self.present(alertController, animated: true, completion: nil)
}
You can use this simple extension with n number of buttons and associated actions swift4 and above
extension UIViewController {
func popupAlert(title: String?, message: String?, actionTitles:[String?], actions:[((UIAlertAction) -> Void)?]) {
let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
for (index, title) in actionTitles.enumerated() {
let action = UIAlertAction(title: title, style: .default, handler: actions[index])
alert.addAction(action)
}
self.present(alert, animated: true, completion: nil)
}
}
you can use it like ,
self.popupAlert(title: "Message", message: "your message", actionTitles: ["first","second","third"], actions:[
{action1 in
//action for first btn click
},
{action2 in
//action for second btn click
},
{action3 in
//action for third btn click
}, nil])
The reason it doesn't work because some value you passed to the function isn't correct. swift doesn't like Objective-C, you can put nil to arguments which are class type without any restriction(might be). Argument otherButtonTitles is defined as non-optional which its type do not have (?)at its end. so you must pass a concrete value to it.
#IBAction func Alert(sender: UIButton) {
var alertView:UIAlertView = UIAlertView()
alertView.title = "Alert!"
alertView.message = "Message"
alertView.delegate = self
alertView.addButtonWithTitle("OK")
alertView.show()
}
Try this
Use this code to display an alertview
let alertController = UIAlertController(title: "Hello Coders", message: "your alert message", preferredStyle: .Alert)
let defaultAction = UIAlertAction(title: "Close Alert", style: .Default, handler: nil)
alertController.addAction(defaultAction)
presentViewController(alertController, animated: true, completion: nil)
Reference: Swift Show Alert using UIAlertController
in xcode 9
let alert = UIAlertController(title: "Alert", message: "message", preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "Ok", style: UIAlertActionStyle.default, handler: nil))
self.present(alert, animated: true, completion: nil)
SWIFT 4 : Simply create a extension to UIViewController as follows:
extension UIViewController {
func showSuccessAlert(withTitle title: String, andMessage message:String) {
let alert = UIAlertController(title: title, message: message,
preferredStyle: UIAlertController.Style.alert)
alert.addAction(UIAlertAction(title: "OK".localized, style:
UIAlertAction.Style.default, handler: nil))
self.present(alert, animated: true, completion: nil)
}
}
Now in your ViewController, directly call above function as if they are provided by UIViewController.
yourViewController.showSuccessAlert(withTitle:
"YourTitle", andMessage: "YourCustomTitle")
Or just do this
let alert = UIAlertController(title: "Alert", message: "Saved Successfully", preferredStyle: UIAlertController.Style.alert)
alert.addAction(UIAlertAction(title: "Ok", style: UIAlertAction.Style.default, handler: nil))
self.present(alert, animated: true, completion: nil)
try This.
Put Bellow Code In Button.
let alert = UIAlertController(title: "Your_Title_Text", message: "Your_MSG", preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "Your_Text", style: UIAlertActionStyle.default, handler: nil))
self.present(alert, animated:true, completion: nil)
Here is a funny example in Swift:
private func presentRandomJoke() {
if let randomJoke: String = jokesController.randomJoke() {
let alertController: UIAlertController = UIAlertController(title:nil, message:randomJoke, preferredStyle: UIAlertControllerStyle.Alert)
alertController.addAction(UIAlertAction(title:"Done", style:UIAlertActionStyle.Default, handler:nil))
presentViewController(alertController, animated:true, completion:nil)
}
}
Here is a pretty simple function of AlertView in Swift :
class func globalAlertYesNo(msg: String) {
let alertView = UNAlertView(title: "Title", message: msg)
alertView.messageAlignment = NSTextAlignment.Center
alertView.buttonAlignment = UNButtonAlignment.Horizontal
alertView.addButton("Yes", action: {
print("Yes action")
})
alertView.addButton("No", action: {
print("No action")
})
alertView.show()
}
You have to pass message as a String where you use this function.
The Old Way: UIAlertView
let alertView = UIAlertView(title: "Default Style", message: "A standard alert.", delegate: self, cancelButtonTitle: "Cancel", otherButtonTitles: "OK")
alertView.alertViewStyle = .Default
alertView.show()
// MARK: UIAlertViewDelegate
func alertView(alertView: UIAlertView, clickedButtonAtIndex buttonIndex: Int) {
switch buttonIndex {
// ...
}
}
The New Way: UIAlertController
let alertController = UIAlertController(title: "Default Style", message: "A standard alert.", preferredStyle: .Alert)
let cancelAction = UIAlertAction(title: "Cancel", style: .Cancel) { (action) in
// ...
}
alertController.addAction(cancelAction)
let OKAction = UIAlertAction(title: "OK", style: .Default) { (action) in
// ...
}
alertController.addAction(OKAction)
self.presentViewController(alertController, animated: true) {
// ...
}