iPad上的UIPopoverPresentationController

Question

我想在UIPopoverPresentationController中呈现一个viewController，就像iOS Setting App一样，当我们选择语言时。它在设备屏幕的中心呈现了一个viewController！

但是，我的结果不是那样的！

这是我的代码：

func rightButtonPressed(rightBarButton: UIBarButtonItem) {
    let detailVC = self.storyboard?.instantiateViewControllerWithIdentifier("ExampleViewController") as! ExampleViewController
    detailVC.modalPresentationStyle = .Popover
    let popOverVC = detailVC.popoverPresentationController
    popOverVC?.permittedArrowDirections = .Any
    popOverVC?.barButtonItem = rightBarButton
    popOverVC?.sourceView = self.view
    popOverVC?.delegate = self

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

代表：

extension DetailViewController: UIPopoverPresentationControllerDelegate {
    func adaptivePresentationStyleForPresentationController(controller: UIPresentationController) -> UIModalPresentationStyle {
        debugPrint(controller.description)
        return .Popover
    }

    func presentationController(controller: UIPresentationController, viewControllerForAdaptivePresentationStyle style: UIModalPresentationStyle) -> UIViewController? {
        let navController = UINavigationController.init(rootViewController: controller.presentedViewController)
        return navController 
    }
}

Answer 1

尝试将演示文稿样式设置为工作表：

detailVC.modalPresentationStyle = UIModalPresentation.FormSheet