How to change the background color of the UIAlertController?
Due to strange behavior of UIActionSheet in iOS 8, I have implemented UIAlertController with UIAction as buttons in it. I would like to change the entire background of the UIAlertController. But I can't find any ways to do it.
Tried even with,
actionController.view.backgroundColor = [UIColor blackColor];
But didn't help me out. Any inputs on this regard will be appreciable.
Thanks in advance.
Solution 1:
You have to step some views deeper:
let subview = actionController.view.subviews.first! as UIView
let alertContentView = subview.subviews.first! as UIView
alertContentView.backgroundColor = UIColor.blackColor()
And maybe you want to keep original corner radius:
alertContentView.layer.cornerRadius = 5;
Sorry for the "Swifting" but i'm not familiar with Objective-C. I hope that's similar.
Of course it's also important to change the title color of the actions. Unfortunately I don't know, how to set the color of actions separately. But this is, how you change all button text colors:
actionController.view.tintColor = UIColor.whiteColor();
EDIT:
The corner radius of the UIAlertController has changed since this answer's been posted! Replace this:
alertContentView.layer.cornerRadius = 5;
to this:
actionContentView.layer.cornerRadius = 15
Solution 2:
maybe you like the use the blur effect in the dark mode. Here is a very easy way to get this:
UIVisualEffectView.appearance(whenContainedInInstancesOf: [UIAlertController.classForCoder() as! UIAppearanceContainer.Type]).effect = UIBlurEffect(style: .dark)
Solution 3:
I have found a hack-ish way of doing it. First you need an extension to allow you to search for the UIVisualEffectView
inside the UIAlertController
:
extension UIView
{
func searchVisualEffectsSubview() -> UIVisualEffectView?
{
if let visualEffectView = self as? UIVisualEffectView
{
return visualEffectView
}
else
{
for subview in subviews
{
if let found = subview.searchVisualEffectsSubview()
{
return found
}
}
}
return nil
}
}
Important: You have to call this function after calling presentViewController
, because only after loading the view controller that the visual effects view is inserted into place. Then you can change the effect associated with it to a dark blur effect:
self.presentViewController(actionController, animated: true, completion: nil)
if let visualEffectView = actionController.view.searchVisualEffectsSubview()
{
visualEffectView.effect = UIBlurEffect(style: .Dark)
}
And this is the final result:
I am honestly surprised myself how well it works! I think this is probably something Apple forgot to add. Also, I haven't yet passed an App through approval with this "hack" (it isn't a hack because we're only using public APIs), but I'm confident there won't be a problem.