ios - 如何在 iPad 的左侧导航栏上正确呈现 actionSheet

Question

我正在尝试使用左侧导航栏项目在 ipad 上呈现一个 actionSheet。问题是 left sidebarItem 不被视为 View ，而是 UIBarButtonItem，因此我在使用 ipad 时收到错误。这段代码是

...

     if ( UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiom.pad ){
                        let button = self.LeftBarItem
                        if let currentPopoverpresentioncontroller = alertController.popoverPresentationController{
    //error start here
                            currentPopoverpresentioncontroller.sourceView = button
                            currentPopoverpresentioncontroller.sourceRect = button.bounds;
   error end here //
                            currentPopoverpresentioncontroller.permittedArrowDirections = UIPopoverArrowDirection.up;
                            self.present(alert, animated: true, completion: nil)
                        }
                    }else{
                        self.present(alert, animated: true, completion: nil)
                    }

Answer 1

这允许用户使用 navigationBar Item 来呈现 popoverPresentationController。

 if let popoverController = alert.popoverPresentationController {
                    popoverController.barButtonItem = self.LeftBarItem as? UIBarButtonItem
                }

                self.present(alert, animated: true, completion: nil)