How to call my custom alert controller function to display in other view controller?

Question

I have write my custom alert view controller.But,I am having error at calling my alert controller from other view controller.It show me the error that I described below.

Answer 1

I see you made as subclass, but in the UIAlertController documentation is written:

The UIAlertController class is intended to be used as-is and does not support subclassing. The view hierarchy for this class is private and must not be modified.

I would recommend you do not go against it. If you need something very custom better to use UIViewController and display with custom behavior.

Answer 2

Change your method like so:

func displayLoadingAlert(viewController: UIViewController?) -> UIAlertController {
    var controllerToPresent = viewController
    if controllerToPresent == nil {
    controllerToPresent = self
}

// Most of your code

controllerToPresent.presentViewController(loadingAlertController, animated: true, completion: nil)

return loadingAlertController
}

Then when you're calling the alert:

loadingAlertController.displayLoadingAlert(self)

Alternatively: Rename the method displayLoadingAlert to loadingAlert

Remove the line:

self.presentViewController(loadingAlertController, animated: true, completion: nil)

then when calling insidethe showAlert() method

let loadingAlertController = loadingAlertController.loadingAlert()
self.presentViewController(loadingAlertController, animated: true, completion: nil)