How to dismiss UIAlertController when tap outside the UIAlertController?

How to dismiss UIAlertController when tap outside the UIAlertController?

I can add a UIAlertAction of style UIAlertActionStyleCancel to dismiss the UIAlertController.

But I want to add the function that when user tap outside the UIAlertController the UIAlertController will dismiss. How to do that? Thank you.

Add a separate cancel action with style UIAlertActionStyleCancel. So that when user taps outside, you would get the callback.

Obj-c

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Alert Title" message:@"A Message" preferredStyle:UIAlertControllerStyleActionSheet];
[alertController addAction:[UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:^(UIAlertAction *action) {
 // Called when user taps outside
}]];

Swift 5.0

let alertController = UIAlertController(title: "Alert Title", message: "A Message", preferredStyle: .actionSheet)             
alertController.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: { 
    action in
         // Called when user taps outside
}))