I have this button who's calling a function(showActionSheetForPost) in another ViewController (TimelineViewController).
My Button:
weak var timeline: TimelineViewController?
#IBAction func moreButtonTapped(sender: AnyObject) {
timeline?.showActionSheetForPost(post!)
}
The other ViewController (TimelineViewController):
class TimelineViewController: UIViewController, TimelineComponentTarget {
#IBOutlet weak var tableView: UITableView!
// MARK: UIActionSheets
func showActionSheetForPost(post: Post) {
if (post.user == PFUser.currentUser()) {
showDeleteActionSheetForPost(post)
} else {
showFlagActionSheetForPost(post)
}
}
func showDeleteActionSheetForPost(post: Post) {
let alertController = UIAlertController(title: nil, message: "Do you want to delete this post?", preferredStyle: .ActionSheet)
let cancelAction = UIAlertAction(title: "Cancel", style: .Cancel, handler: nil)
alertController.addAction(cancelAction)
let destroyAction = UIAlertAction(title: "Delete", style: .Destructive) { (action) in
post.deleteInBackgroundWithBlock({ (success: Bool, error: NSError?) -> Void in
if (success) {
self.timelineComponent.removeObject(post)
} else {
// restore old state
self.timelineComponent.refresh(self)
}
})
}
alertController.addAction(destroyAction)
self.presentViewController(alertController, animated: true, completion: nil)
}
func showFlagActionSheetForPost(post: Post) {
let alertController = UIAlertController(title: nil, message: "Do you want to flag this post?", preferredStyle: .ActionSheet)
let cancelAction = UIAlertAction(title: "Cancel", style: .Cancel, handler: nil)
alertController.addAction(cancelAction)
let destroyAction = UIAlertAction(title: "Flag", style: .Destructive) { (action) in
post.flagPost(PFUser.currentUser()!)
}
alertController.addAction(destroyAction)
self.presentViewController(alertController, animated: true, completion: nil)
}
}
My problem:
when I touch the Button (moreButtonTapped) The Action Sheet doesn't appear.
Thank you very much
You need to do like:
TimelineViewController().showActionSheetForPost(post!)
or set
weak var timeline: TimelineViewController()
#iamalizade
I took a screenshot of all the errors in my TimelineViewController
The errors
Related
I have made an app that recognize's a piece of art/drawing/paper etc using ARKit. When it recognize's the images it switches to another View Controller and tells you about it. It can recognize one piece of art. The question is how can i have the app recognize multiple drawings. Here is the code.
AR View Controller:
import UIKit
import SpriteKit
import ARKit
import AVFoundation
struct ImageInformation {
let name: String
let description: String
let image: UIImage
}
class ViewController: UIViewController, ARSKViewDelegate {
#IBOutlet var sceneView: ARSKView!
#IBAction func options(){
let alert = UIAlertController(title: "Options", message: "Select one of the options below to continue.", preferredStyle: .actionSheet)
alert.addAction(UIAlertAction(title: "Enable Flashlight", style: .default, handler: { action in
//Enable Flashlight function
func toggleTorch(on: Bool) {
guard let device = AVCaptureDevice.default(for: AVMediaType.video),
device.hasTorch
else { return }
do {
try device.lockForConfiguration()
device.torchMode = on ? .on : .off
device.unlockForConfiguration()
} catch {
//Torch can not be used.
let alert = UIAlertController(title: "Flashlight Error", message: "We are unable to activate the flashlight. This could be because the flashlight is being used by another app", preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "Dissmis", style: .default, handler: nil))
alert.addAction(UIAlertAction(title: "Restart App", style: .destructive, handler: { action in
fatalError("The flashlight could not be used and user restarted app.")
}))
self.present(alert, animated: true)
}
}
toggleTorch(on: true)
}))
//Continue working on this function when you get back!!!
alert.addAction(UIAlertAction(title: "Disable Flashlight", style: .default, handler: { action in
//Enable flashlight function here
func toggleTorch(off: Bool) {
guard let device = AVCaptureDevice.default(for: AVMediaType.video),
device.hasTorch
else { return }
do {
try device.lockForConfiguration()
device.torchMode = off ? .on : .off
device.unlockForConfiguration()
} catch {
//Torch can not be used.
let alert = UIAlertController(title: "Flashlight Error", message: "We are unable to activate the flashlight. This could be because the flashlight is being used by another app", preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "Dissmis", style: .default, handler: nil))
alert.addAction(UIAlertAction(title: "Restart App", style: .destructive, handler: { action in
fatalError("The flashlight could not be used and user restarted app.")
}))
self.present(alert, animated: true)
}
}
toggleTorch(off: false)
}))
alert.addAction(UIAlertAction(title: "Clear Recently Visited Artworks", style: .destructive, handler: { action in
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let secondViewController = storyboard.instantiateViewController(withIdentifier: "action_done")
self.present(secondViewController, animated: false, completion: nil)
}))
alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
self.present(alert, animated: true)
}
var selectedImage : ImageInformation?
let images = ["flower" : ImageInformation(name: "Flower Drawing", description: "This is a drawing of a flower and was made by the developer of this app. It was intended to be a thank you card for a teacher on Teacher appreciation day. The Teacher enjoyed the project.", image: UIImage(named: "flower")!)]
override func viewDidLoad() {
super.viewDidLoad()
sceneView.delegate = self
sceneView.showsFPS = false
sceneView.showsNodeCount = false
if let scene = SKScene(fileNamed: "Scene") {
sceneView.presentScene(scene)
}
guard let referenceImages = ARReferenceImage.referenceImages(inGroupNamed: "AR Resources", bundle: nil) else {
let alert = UIAlertController(title: "Resources not Found", message: "The files needed for this application to work propely can not be found. What would you like to do about this?", preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "Continue Anyway", style: .default, handler: nil))
alert.addAction(UIAlertAction(title: "Restart App", style: .default, handler: { action in
fatalError("The Recources could not be found on the users device.")
}))
self.present(alert, animated: true)
return
}
let configuration = ARWorldTrackingConfiguration()
configuration.detectionImages = referenceImages
sceneView.session.run(configuration, options: [.resetTracking, .removeExistingAnchors])
}
// MARK: - ARSKViewDelegate
func view(_ view: ARSKView, nodeFor anchor: ARAnchor) -> SKNode? {
if let imageAnchor = anchor as? ARImageAnchor,
let referenceImageName = imageAnchor.referenceImage.name,
let scannedImage = self.images[referenceImageName] {
self.selectedImage = scannedImage
self.performSegue(withIdentifier: "switch", sender: self)
return imageSeenMarker()
}
return nil
}
private func imageSeenMarker() -> SKLabelNode {
let labelNode = SKLabelNode(text: "✅")
labelNode.horizontalAlignmentMode = .center
labelNode.verticalAlignmentMode = .center
return labelNode
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "switch"{
if let imageInformationVC = segue.destination as? ImageInformationViewController,
let actualSelectedImage = selectedImage {
imageInformationVC.imageInformation = actualSelectedImage
}
}
}
}
Information View Controller:
import Foundation
import UIKit
class ImageInformationViewController : UIViewController {
#IBOutlet weak var nameLabel: UILabel!
#IBOutlet weak var imageView: UIImageView!
#IBOutlet weak var descriptionText: UILabel!
var imageInformation : ImageInformation?
override func viewDidLoad() {
super.viewDidLoad()
if let actualImageInformation = imageInformation {
self.nameLabel.text = actualImageInformation.name
self.imageView.image = actualImageInformation.image
self.descriptionText.text = actualImageInformation.description
}
}
#IBAction func dismissView(_ sender: Any) {
self.dismiss(animated: true, completion: nil)
}
}
How Can i do this?
Thanks!
The function referenceImages(inGroup:bundle:) loads all reference images from your assets. Just put multiple images into your AR Resource Group in your Assets and assign a unique name for all of them.
Is there any separate global function to add a different style and a different handler for alerts?
My function from AppDelegate looks like this:
static func showAlertView(vc : UIViewController, titleString : String , messageString: String) ->()
{
let alertView = UIAlertController(title: titleString, message: messageString, preferredStyle: .alert)
let alertAction = UIAlertAction(title: "ok", style: .cancel) { (alert) in
vc.dismiss(animated: true, completion: nil)
}
alertView.addAction(alertAction)
vc.present(alertView, animated: true, completion: nil)
}
You just need to add more parameters to your function. In the code below I've added the following: controllerStyle for UIAlertController, actionStyle for UIAlertAction and action for UIAlertAction handler.
static func showAlertView(vc : UIViewController, titleString : String , messageString: String, controllerStyle: UIAlertController.Style = .alert, actionStyle: UIAlertAction.Style = .cancel, action: #escaping () -> () = {}) {
let alertView = UIAlertController(title: titleString, message: messageString, preferredStyle: controllerStyle)
let alertAction = UIAlertAction(title: "ok", style: .cancel) { (alert) in
if action == {} {
vc.dismiss(animated: true, completion: nil)
} else {
action()
}
}
alertView.addAction(alertAction)
vc.present(alertView, animated: true, completion: nil)
}
everyone I am making Alert from my AlertController, but I want after action button "OK" is pressed, open LoginController, how I can do that?I tried to do that just like below, but it's not working
AlertController:
class AlertController: NSObject {
class func showErrorWith(title:String? = nil, message:String? = nil, controller: UIViewController , complition:(() -> ())?){
let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "OK", style: .default, handler: { (action) in
// let storyboard = UIStoryboard(name: "Main", bundle: nil)
// let viewController = storyboard.instantiateViewController(withIdentifier :"LoginVC")
// self.present(viewController, animated: true)
//
}))
controller.present(alert, animated: true, completion: nil)
}
It's happen because you call self.present in this code self - It's kind of NSObject.
Just call controller.present(viewController, animated:true);
func ShowAlert(vc: UIViewController, title: String, message:String, affirmButton: String = "OK", cancelButton: String = "Cancel", onAffirmation: (Void) -> (Void) = { })
{
let alertView = UIAlertController(title: title, message: message, preferredStyle: .Alert)
alertView.addAction(UIAlertAction(title: affirmButton, style: UIAlertActionStyle.Default, handler:{(action) in
onAffirmation()
}))
alertView.addAction(UIAlertAction(title: cancelButton, style: UIAlertActionStyle.Default, handler: nil))
vc.presentViewController(alertView, animated: true, completion: nil)
}
Opening the UIAlertController on button click, the action is going to open but main issue is the UIAlertAction methods are not performed on its click. Here is Code block :
class HomeViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// getData()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
//menuBtn is the button
#IBAction func menuBtn(sender: UIButton) {
let optionMenu = UIAlertController(title: nil, message: nil, preferredStyle: .ActionSheet)
let orders = UIAlertAction(title: "Orders", style: .Default, handler: { (alert: UIAlertAction!) -> Void in
let alertViewController = self.storyboard?.instantiateViewControllerWithIdentifier("OrdersViewController") as! OrdersViewController
self.presentViewController(alertViewController, animated: true, completion: nil)
})
let about = UIAlertAction(title: "About", style: .Default, handler: {(alert: UIAlertAction!) -> Void in
let aboutObject = self.storyboard?.instantiateViewControllerWithIdentifier("AboutViewController") as! AboutViewController
self.presentViewController(aboutObject, animated: true, completion: nil)
})
let contactUs = UIAlertAction(title: "Contact Us", style: .Default, handler: {(alert: UIAlertAction!) -> Void in
let alertViewController = self.storyboard?.instantiateViewControllerWithIdentifier("ContactViewController") as! ContactViewController
self.presentViewController(alertViewController, animated: true, completion: nil)
})
let login = UIAlertAction(title: "LogIn", style: .Default, handler: {(alert: UIAlertAction!) -> Void in
let alertViewController = self.storyboard?.instantiateViewControllerWithIdentifier("LoginViewController") as! LoginViewController
self.presentViewController(alertViewController, animated: true, completion: nil)
})
let cancelAction = UIAlertAction(title: "Cancel", style: .Cancel, handler: nil)
optionMenu.addAction(orders)
optionMenu.addAction(about)
optionMenu.addAction(contactUs)
optionMenu.addAction(login)
optionMenu.addAction(cancelAction)
self.presentViewController(optionMenu, animated: true, completion: nil)
}
This is code is working fine, I have checked it's opening new viewController as well.
Cross check points:
Controller class and stroybaord are connected
Storyboard ID has been assigned
IBAction must be connected to IBOutlet
On the Button click Action you have to write code.. Try This code.
let alert = UIAlertController(title: "Saved", message: "Selected Frame is Saved", preferredStyle: .Alert)
alert.addAction(UIAlertAction(title: "Ok", style:.Default , handler: { (UIAlertAction) in
}))
//Add action like this
self.presentViewController(alert, animated: true, completion: nil)
Still need any help feel free to ask.
First of all check if the button action is touch up inside. Make the button action as touch up inside. Below code works for me. Hope this works for you as well. Change the action title according to your need.
#IBAction func menuBtn(sender: AnyObject) {
let actionSheet = UIAlertController()
let criticalAction = UIAlertAction(title : "CRITICAL" , style : UIAlertActionStyle.Default){
(action) in
//This section will be executed when the buttons are pressed
//Do your work here.
debugPrint("CRITICAL")
}
let highAction = UIAlertAction(title : "HIGH" , style : UIAlertActionStyle.Default){
(action) in
//This section will be executed when the buttons are pressed
//Do your work here.
debugPrint("HIGH")
}
actionSheet.addAction(criticalAction)
actionSheet.addAction(highAction)
self.presentViewController(actionSheet, animated: true, completion: nil)
}
I've been looking up a lot of tutorials on UIAlertController. Thus far, the way I found was to activate a UIAlertController by linking it to a button or label and then call a IBAction.
I tried to replicate the code to automatically pop an alert when user enters the app (I wanted to ask the user if they want to go through the tutorial). However, I keep getting the error:
Warning: Attempt to present UIAlertController on MainViewController whose view is not in the window hierarchy!
Then I tried to add the UIAlertController to the MainViewController via addChildViewController and addSubview. However, I get the error:
Application tried to present modally an active controller
I figured that I cannot use the presentViewController function and commented it out.
The UIAlertController is displayed BUT when I tried to click on the cancel or the never button, this error occurs.
Trying to dismiss UIAlertController with unknown presenter.
I am really stumped. Can someone share what I am doing wrong? Thank you so much. Here is the code.
func displayTutorial() {
alertController = UIAlertController(title: NSLocalizedString("tutorialAlert", comment: ""), message: NSLocalizedString("tutorialMsg", comment: ""), preferredStyle: .ActionSheet)
self.addChildViewController(alertController)
self.view.addSubview(alertController.view)
alertController.didMoveToParentViewController(self)
alertController.view.frame.origin.x = self.view.frame.midX
alertController.view.frame.origin.y = self.view.frame.midY
//alertController.popoverPresentationController?.sourceView = self.view*/
let OkAction = UIAlertAction(title: NSLocalizedString("yesh", comment: ""), style: .Destructive) { (action) in
}
alertController.addAction(OkAction)
let cancelAction = UIAlertAction(title: NSLocalizedString("notNow", comment: ""), style: .Destructive) { (action) in
//println(action)
self.tutorial = 1
self.presentedViewController?.dismissViewControllerAnimated(true, completion: nil)
}
alertController.addAction(cancelAction)
let neverAction = UIAlertAction(title: NSLocalizedString("never", comment: ""), style: .Cancel) { (action) in
self.tutorial = 1
}
alertController.addAction(neverAction)
//self.presentViewController(alertController, animated: false) {}
}
I found the solution. Apparently, I cannot call the UIAlertController from the func viewDidLoad. I must call the function from viewDidAppear. So my code now is
override func viewDidAppear(animated: Bool) {
if tutorial == 0 {
displayTutorial(self.view)
}
}
func displayTutorial(sender:AnyObject) {
let alertController = UIAlertController(title: NSLocalizedString("tutorialAlert", comment: ""), message: NSLocalizedString("tutorialMsg", comment: ""), preferredStyle: .ActionSheet)
let OkAction = UIAlertAction(title: NSLocalizedString("yesh", comment: ""), style: .Destructive) { (action) in
}
alertController.addAction(OkAction)
let cancelAction = UIAlertAction(title: NSLocalizedString("notNow", comment: ""), style: .Default) { (action) in
//println(action)
self.tutorial = 1
self.presentedViewController?.dismissViewControllerAnimated(true, completion: nil)
}
alertController.addAction(cancelAction)
let neverAction = UIAlertAction(title: NSLocalizedString("never", comment: ""), style: .Cancel) { (action) in
self.tutorial = 1
}
alertController.addAction(neverAction)
self.presentViewController(alertController, animated: true, completion: nil)
if let pop = alertController.popoverPresentationController {
let v = sender as UIView
pop.sourceView = view
pop.sourceRect = v.bounds
}
}
Thanks to this posting: Warning: Attempt to present * on * whose view is not in the window hierarchy - swift
Below UIAlertController with extension would help you show alert with dynamic number of buttons with completion handler for selected index
extension UIViewController {
func displayAlertWith(message:String) {
displayAlertWith(message: message, buttons: ["Dismiss"]) { (index) in
}
}
func displayAlertWith(message:String, buttons:[String], completion:((_ index:Int) -> Void)!) -> Void {
displayAlertWithTitleFromVC(vc: self, title: Bundle.main.infoDictionary!["CFBundleDisplayName"] as! String, andMessage: message, buttons: buttons, completion: completion)
}
func displayAlertWithTitleFromVC(vc:UIViewController, title:String, andMessage message:String, buttons:[String], completion:((_ index:Int) -> Void)!) -> Void {
let alertController = UIAlertController(title: title, message: message, preferredStyle: .alert)
for index in 0..<buttons.count {
let action = UIAlertAction(title: buttons[index], style: .default, handler: {
(alert: UIAlertAction!) in
if(completion != nil){
completion(index)
}
})
alertController.addAction(action)
}
DispatchQueue.main.async {
vc.present(alertController, animated: true, completion: nil)
}
}
}
If you need to auto dismiss the alert you can call dismiss on presented view controller after some delay.
DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 1) {
vc.dismiss(animated: true, completion: nil)
}
Hope this might help you.