IOS 8 iPad App Crashes When UIActivityViewController Is Called

Question

When a UIActivityViewController is called on the iPhone in this app, it works perfectly, but when called on a iPad, the app crashes. Below is the code I used:

func shareButtonPress() {

    //when the share button is pressed, default share phrase is added, cropped image of highscore is added

    var sharingItems = [AnyObject]()

    var shareButtonHighscore = NSUserDefaults.standardUserDefaults().objectForKey("highscore") as Int!

    sharingItems.append("Just hit \(shareButtonHighscore)! Beat it! #Swath")

    UIGraphicsBeginImageContextWithOptions(UIScreen.mainScreen().bounds.size, false, 0);
    self.view.drawViewHierarchyInRect(view.bounds, afterScreenUpdates: true)
    var image:UIImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    sharingItems.append(image)

    let activityViewController = UIActivityViewController(activityItems: sharingItems, applicationActivities: nil)

    var barButtonItem: UIBarButtonItem! = UIBarButtonItem()

    activityViewController.excludedActivityTypes = [UIActivityTypeCopyToPasteboard,UIActivityTypeAirDrop,UIActivityTypeAddToReadingList,UIActivityTypeAssignToContact,UIActivityTypePostToTencentWeibo,UIActivityTypePostToVimeo,UIActivityTypePrint,UIActivityTypeSaveToCameraRoll,UIActivityTypePostToWeibo]

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

}

As you can see, I'm programming in Swift, in the SpriteKit Framework, and I don't understand why the app is crashing.

I'm receiving this error:

Terminating app due to uncaught exception 'NSGenericException', reason: 'UIPopoverPresentationController (<_UIAlertControllerActionSheetRegularPresentationController: 0x7fc7a874bd90>) should have a non-nil sourceView or barButtonItem set before the presentation occurs.'

What can I do to fix this problem?

Answer 1

Before presenting the UIActivityViewController, add in this line of code:

activityViewController.popoverPresentationController?.sourceView = self.view

This way, the view controller knows in which frame of the GameViewController to appear in.

Answer 2

If you read the error it says how to fix it, you need to set the barButtonItem or sourceView from which to present the popover from, in your case:

func shareButtonPress(pressedButton: UIBarButtonItem) { 

    ...

    activityViewController.popoverPresentationController.barButtonItem = pressedButton

    self.presentViewController(activityViewController, animated: true, completion: nil)
}