ios - (<UIPopoverPresentationController : 0x7fdb10687050>) should have a non-nil sourceView or barButtonItem set before the presentation occurs. '

Question

我在标签栏 Controller 中创建了一个导航项按钮。

class TabBarContoller: UITabBarController,UIPopoverPresentationControllerDelegate {
 ...
        let languageBtn = UIBarButtonItem(title: "EN", style: UIBarButtonItemStyle.Plain, target: self, action: #selector(Language))
      // navigationItem.rightBarButtonItem = [rightButton , languageBtn]
        navigationItem.setRightBarButtonItems([rightButton,languageBtn], animated: true)

我想在选中此按钮时运行此功能，这将弹出一个 View Controller :

 func showLanguagePopOver(base: UIView)  {
        let popOverContent = self.storyboard?.instantiateViewControllerWithIdentifier("Languages")as! Languages
        popOverContent.preferredContentSize = CGSizeMake(150, 150)
        let nav = UINavigationController(rootViewController: popOverContent)
        nav.modalPresentationStyle = .Popover
        let popOver = nav.popoverPresentationController
        popOver?.delegate = self
        popOver?.sourceView = base
        popOver?.sourceRect = base.bounds
        popOver?.sourceRect = CGRect(x: 0, y: 0, width: 100, height: 25)
        self.presentViewController(nav, animated: true, completion: nil)
    }

我试着这样调用它:

func Language()
{
  showLanguagePopOver(UIView)

  }

它没有用，有什么帮助吗？

Answer 1

swift 5

let controller = UIActivityViewController(activityItems: [link], applicationActivities: nil)
        if UIDevice.current.userInterfaceIdiom == .pad {
            controller.popoverPresentationController?.sourceView = self.view
            controller.modalPresentationStyle = .pageSheet
        }
        vc.present(controller, animated: true, completion: nil)

呈现 View Controller 在 iPad 版本中有所不同，它需要您分配某种源 View ，否则它会崩溃。