ios - example - ui alert controller swift 4

ios: presente UIAlertController encima de todo independientemente de la jerarquía de vistas

Question

Estoy tratando de tener una clase de ayuda que presente un UIAlertController . Ya que es una clase auxiliar, quiero que funcione independientemente de la jerarquía de vistas y sin información sobre ella. Puedo mostrar la alerta, pero cuando está siendo descartada, la aplicación se bloqueó con:

*** Terminating app due to uncaught exception ''NSInternalInconsistencyException'',
reason: ''Trying to dismiss UIAlertController <UIAlertController: 0x135d70d80>
 with unknown presenter.''

Estoy creando la ventana emergente con:

guard let window = UIApplication.shared.keyWindow else { return }
let view = UIView()
view.isUserInteractionEnabled = true
window.insertSubview(view, at: 0)
window.bringSubview(toFront: view)
// add full screen constraints to view ...

let controller = UIAlertController(
  title: "confirm deletion?",
  message: ":)",
  preferredStyle: .alert
)

let deleteAction = UIAlertAction(
  title: "yes",
  style: .destructive,
  handler: { _ in
    DispatchQueue.main.async {
      view.removeFromSuperview()
      completion()
    }
  }
)
controller.addAction(deleteAction)

view.insertSubview(controller.view, at: 0)
view.bringSubview(toFront: controller.view)
// add centering constraints to controller.view ...

Cuando toco yes , la aplicación se bloqueará y el controlador no será golpeado antes del bloqueo. No puedo presentar el UIAlertController porque esto dependería de la jerarquía de vista actual, mientras que quiero que la ventana emergente sea independiente

EDITAR: Solución rápida Gracias a @Vlad por la idea. Parece que operar en una ventana separada es mucho más simple. Así que aquí hay una solución Swift que funciona:

class Popup {
  private var alertWindow: UIWindow
  static var shared = Popup()

  init() {
    alertWindow = UIWindow(frame: UIScreen.main.bounds)
    alertWindow.rootViewController = UIViewController()
    alertWindow.windowLevel = UIWindowLevelAlert + 1
    alertWindow.makeKeyAndVisible()
    alertWindow.isHidden = true
  }

  private func show(completion: @escaping ((Bool) -> Void)) {
    let controller = UIAlertController(
      title: "Want to do it?",
      message: "message",
      preferredStyle: .alert
    )

    let yesAction = UIAlertAction(
      title: "Yes",
      style: .default,
      handler: { _ in
        DispatchQueue.main.async {
          self.alertWindow.isHidden = true
          completion(true)
        }
    })

    let noAction = UIAlertAction(
      title: "Not now",
      style: .destructive,
      handler: { _ in
        DispatchQueue.main.async {
          self.alertWindow.isHidden = true
          completion(false)
        }
    })

    controller.addAction(noAction)
    controller.addAction(yesAction)
    self.alertWindow.isHidden = false
    alertWindow.rootViewController?.present(controller, animated: false)
  }
}

Answer 1

Aquí hay una extensión Swift 3 para ello:

public extension UIAlertController {
    func show() {
        let win = UIWindow(frame: UIScreen.main.bounds)
        let vc = UIViewController()
        vc.view.backgroundColor = .clear
        win.rootViewController = vc
        win.windowLevel = UIWindowLevelAlert + 1
        win.makeKeyAndVisible()    
        vc.present(self, animated: true, completion: nil)
    }
}

Simplemente configure su UIAlertController, y luego llame:

alert.show()

¡No más ligado por la jerarquía de Controladores de Vista!

Answer 2

Ejemplo de Swift 3

let alertWindow = UIWindow(frame: UIScreen.main.bounds)
alertWindow.rootViewController = UIViewController()
alertWindow.windowLevel = UIWindowLevelAlert + 1

let alert = UIAlertController(title: "AlertController Tutorial", message: "Submit something", preferredStyle: .alert)

alertWindow.makeKeyAndVisible()
alertWindow.rootViewController?.present(alert, animated: true, completion: nil)

Answer 3

Prefiero presentarlo en UIApplication.shared.keyWindow.rootViewController, en lugar de usar su lógica. Así que puedes hacer lo siguiente:

UIApplication.shared.keyWindow.rootViewController.presentController(yourAlert, animated: true, completion: nil)

EDITADO:

Tengo una categoría antigua de ObjC, donde he usado el siguiente método de demostración, que utilicé, si no se proporcionó un controlador para presentar desde:

- (void)show
{
    self.alertWindow = [[UIWindow alloc] initWithFrame: [UIScreen mainScreen].bounds];
    self.alertWindow.rootViewController = [UIViewController new];
    self.alertWindow.windowLevel = UIWindowLevelAlert + 1;
    [self.alertWindow makeKeyAndVisible];
    [self.alertWindow.rootViewController presentViewController: self animated: YES completion: nil];
}

Añadida toda la categoría, si alguien la necesita.

#import "UIAlertController+ShortMessage.h"
#import <objc/runtime.h>

@interface UIAlertController ()
@property (nonatomic, strong) UIWindow* alertWindow;
@end

@implementation UIAlertController (ShortMessage)

- (void)setAlertWindow: (UIWindow*)alertWindow
{
    objc_setAssociatedObject(self, @selector(alertWindow), alertWindow, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

- (UIWindow*)alertWindow
{
    return objc_getAssociatedObject(self, @selector(alertWindow));
}

+ (UIAlertController*)showShortMessage: (NSString*)message fromController: (UIViewController*)controller
{
    return [self showAlertWithTitle: nil shortMessage: message fromController: controller];
}

+ (UIAlertController*)showAlertWithTitle: (NSString*)title shortMessage: (NSString*)message fromController: (UIViewController*)controller
{
    return [self showAlertWithTitle: title shortMessage: message actions: @[[UIAlertAction actionWithTitle: @"Ok" style: UIAlertActionStyleDefault handler: nil]] fromController: controller];
}

+ (UIAlertController*)showAlertWithTitle: (NSString*)title shortMessage: (NSString*)message actions: (NSArray<UIAlertAction*>*)actions fromController: (UIViewController*)controller
{
    UIAlertController* alert = [UIAlertController alertControllerWithTitle: title
                                                    message: message
                                             preferredStyle: UIAlertControllerStyleAlert];

    for (UIAlertAction* action in actions)
    {
        [alert addAction: action];
    }

    if (controller)
    {
        [controller presentViewController: alert animated: YES completion: nil];
    }
    else
    {
        [alert show];
    }

    return alert;
}

+ (UIAlertController*)showAlertWithMessage: (NSString*)message actions: (NSArray<UIAlertAction*>*)actions fromController: (UIViewController*)controller
{
    return [self showAlertWithTitle: @"" shortMessage: message actions: actions fromController: controller];
}

- (void)show
{
    self.alertWindow = [[UIWindow alloc] initWithFrame: [UIScreen mainScreen].bounds];
    self.alertWindow.rootViewController = [UIViewController new];
    self.alertWindow.windowLevel = UIWindowLevelAlert + 1;
    [self.alertWindow makeKeyAndVisible];
    [self.alertWindow.rootViewController presentViewController: self animated: YES completion: nil];
}

@end

Answer 4

en Swift 4.1 y Xcode 9.4.1

Estoy llamando a la función de alerta de mi clase compartida

//This is my shared class
import UIKit

class SharedClass: NSObject {

static let sharedInstance = SharedClass()
    //This is alert function
    func alertWindow(title: String, message: String) {
        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)
    }
    private override init() {
    }
}

Estoy llamando a esta función de alerta en mi controlador de vista requerido como este.

//I''m calling this function into my second view controller
SharedClass.sharedInstance.alertWindow(title:"Title message here", message:"Description message here")

Answer 5

 func windowErrorAlert(message:String){
    let alert = UIAlertController(title: "Error", message: message, preferredStyle: .alert)
    let window = UIWindow(frame: UIScreen.main.bounds)
    window.rootViewController = UIViewController()
    let okAction = UIAlertAction(title: "Ok", style: .default) { (action) -> Void in
        alert.dismiss(animated: true, completion: nil)
        window.resignKey()
        window.isHidden = true
        window.removeFromSuperview()
        window.windowLevel = UIWindowLevelAlert - 1
        window.setNeedsLayout()
    }

    alert.addAction(okAction)
    window.windowLevel = UIWindowLevelAlert + 1
    window.makeKeyAndVisible()

    window.rootViewController?.present(alert, animated: true, completion: nil)
}

Cree un UIAlertController en la parte superior de toda la vista y también cierre y devuelva el enfoque a su rootViewController.