UIPopoverPresentationController Swift

Question

我使用的是故事板和AutoLayout。有两个场景，一个是我的主视图控制器，带有一个工具栏和几个UIBarButtonItems，另一个是一个UIViewController，应该只显示一个UILabel。当用户点击我的主视图控制器中的工具栏时，我用以下代码显示弹出窗口：

func presentPopover(viewCtrl: UIViewController, item: UIBarButtonItem) {
viewCtrl.modalPresentationStyle = .Popover
let popover: UIPopoverPresentationController = viewCtrl.popoverPresentationController!
popover.permittedArrowDirections = .Any
popover.barButtonItem = item
self.presentViewController(viewCtrl, animated: true, completion: nil)
}

helpView = UIStoryboard(name: "Main", bundle: nil).instantiateViewControllerWithIdentifier("HelpView“) as? HelpVC
if helpView != nil {
    presentPopover(helpView!, helpButton)
}

显示视图，但没有可见的子视图(UILabel)。同样奇怪的行为也会发生，当我设置故事板segues而不是从代码中进行popover演示时。然而，当我在我的UINavigationController上推送完全相同的视图时，一切都显示得很好。我是不是遗漏了什么？

致以最好的问候，奥利弗

Answer 1

将大小调整为所需大小。如果传入的话，可以设置barbutton而不是sourceView。

    if let controller = viewCtrl {
        controller.preferredContentSize = CGSizeMake(200,25)
        controller.modalPresentationStyle = UIModalPresentationStyle.Popover
        if let popover = controller.popoverPresentationController  {
            popover.delegate = self
            popover.sourceView = viewCtrl.view
            popover.sourceRect = CGRectMake(0,-5, 50, 50)
            popover.permittedArrowDirections = .Any
            self.presentViewController(controller, animated: true, completion: nil)
        }
    }

Answer 2

最佳教程click here

• 为弹出菜单创建一个XIB和swift文件。(例如MenuViewController)
• create用于显示弹出菜单的另一个xib或情节提要视图控制器文件。(例如ViewController)
• in viewController文件add UIPopoverPresentationControllerDelegate
• add button in ViewController并创建IBAction并编写以下代码。

@IBAction func onClickMenu(_ sender: UIButton)
    {
        if btnMenu.isSelected
        {
            btnMenu.setImage(UIImage(named: "arrow_orange"), for: UIControlState.normal)

            btnMenu.isSelected = false

            self.dismiss(animated: true, completion: nil)
        }
        else
        {
            btnMenu.setImage(UIImage(named: "up_arrow_orange"), for: UIControlState.normal)

            btnMenu.isSelected = true

            let popMenu = MenuViewController(nibName: "MenuViewController", bundle: nil)
            popMenu.modalPresentationStyle = UIModalPresentationStyle.popover

            popMenu.preferredContentSize = CGSize.init(width: 320, height: 265)

            popMenu.vcPush = self

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

            let popController :  UIPopoverPresentationController = popMenu.popoverPresentationController!

            popController.permittedArrowDirections = UIPopoverArrowDirection.up

            popController.delegate = self

            //popController?.barButtonItem = nil

            popController.sourceView = self.view

            popController.sourceRect = CGRect.init(x: 525, y: 30, width: 10, height: 10)
        }
    }

最佳教程click here