UIModalPresentationPopover for iPhone 6 Plus in landscape doesn't display popover

问题

I want to always present a ViewController in a popover on all devices and all orientations. I tried to accomplish this by adopting the UIPopoverPresentationControllerDelegate and setting the sourceView and sourceRect.

This works very well for all devices and orientations, except the iPhone 6 Plus in landscape. In that case the view controller slides up from the bottom of the screen in a form sheet. How can I prevent that so that it will always appear in a popover?

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
let popoverPresentationController = segue.destinationViewController.popoverPresentationController
popoverPresentationController?.delegate = self
popoverPresentationController?.sourceView = self.titleLabel!.superview
popoverPresentationController?.sourceRect = self.titleLabel!.frame }

func adaptivePresentationStyleForPresentationController(controller: UIPresentationController) -> UIModalPresentationStyle {
return UIModalPresentationStyle.None }

All device are under iOS 8.2 or higher

回答1:

Implement the new adaptivePresentationStyleForPresentationController:traitCollection: method of UIAdaptivePresentationControllerDelegate:

- (UIModalPresentationStyle)adaptivePresentationStyleForPresentationController:(UIPresentationController *)controller traitCollection:(UITraitCollection *)traitCollection {
    // This method is called in iOS 8.3 or later regardless of trait collection, in which case use the original presentation style (UIModalPresentationNone signals no adaptation)
    return UIModalPresentationNone;
}

UIModalPresentationNone tells the presentation controller to use the original presentation style which in your case will display a popover.

回答2:

In Swift 3, if you implemented the original adaptivePresentationStyle method, simply adding this code works:

func adaptivePresentationStyle(for controller: UIPresentationController, traitCollection: UITraitCollection) -> UIModalPresentationStyle {
    return adaptivePresentationStyle(for: controller)
}

回答3:

Apple designed the iPhone 6 Plus presentation to behave that way, based on its size class.

To prevent the modal presentation on the iPhone 6 Plus, you'll have to override the trait collection (horizontal size).

You should be able to set the overrideTraitCollection property for the presentation controller:

presentedVC.presentationController.overrideTraitCollection = [UITraitCollection traitCollectionWithHorizontalSizeClass:UIUserInterfaceSizeClassCompact];

(Sorry for the Objective C! I haven't learned Swift yet.)

回答4:

A note to people having issues with this:

This

- (UIModalPresentationStyle)adaptivePresentationStyleForPresentationController:(UIPresentationController *) controller traitCollection:(UITraitCollection *)traitCollection {
    return UIModalPresentationNone;
}

Is not the same as this

- (UIModalPresentationStyle)adaptivePresentationStyleForPresentationController: (UIPresentationController * ) controller {
    return UIModalPresentationNone;
}

The later will not get called / work the same as the former.

来源：https://stackoverflow.com/questions/30378249/uimodalpresentationpopover-for-iphone-6-plus-in-landscape-doesnt-display-popove