UIAlertController subclass issue swift

问题

I want to create a UIAlertController's subclass but I'm going crazy because I have problem with constructor, this is my subclass:

class loginAlert :  UIAlertController {

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)

    }

}

I think that this subclass must have the constructor : UIAlertController(title: String, message: String, preferredStyle: UIAlertControllerStyle) , because it's a subclass of UIAlertController , but when I do

loginAlert(title: "test", message: "test", preferredStyle: .Alert)

I get error , why where Do I wrong?

回答1:

From the UIAlertController Class Reference:

Subclassing Notes 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.

You can create a view controller whose view contains transparency and whose UIModalPresentationStyle is .OverCurrentContext and UIModalTransitionStyle is .CrossDissolve for a very similar effect.

Or you can write an extension on UIAlertController that can add methods that need to be shared across classes (e.g. a method that presents a reoccurring alert). For more information about extensions, see here.

回答2:

function that create a UIAlertController outside a class

public  func alert () {
    let alert = UIAlertController(title: "Title", message: "I don't feel creative", preferredStyle: UIAlertControllerStyle.Alert)
    // As many action as you want
    let action = UIAlertAction(title: "OK", style: UIAlertActionStyle.Cancel, handler: nil)
    alert.addAction(action)
    self.presentViewController(alert, animated: true, completion: nil)
}

but as beyowulf said you can use an extension if you want to add method to UIAlertController

来源：https://stackoverflow.com/questions/33904935/uialertcontroller-subclass-issue-swift

标签

ios

swift

uialertcontroller