这个弹出窗口类的名称是什么？

我找不到这个类的名称'popover'。苹果在他们的应用程序中大量使用它。

我已经寻找过popover, NSAlert、自定义隐藏/可见视图等等。

这叫什么？

This is UIAlertController。在ios 7之前它被称为UIActionSheet

A UIAlertController对象向用户显示警报消息。此类替换了用于显示警报的 UIActionSheet 和 UIAlertView 类。

    @IBAction func showActionSheetTapped(sender: AnyObject) {
  //Create the AlertController
  let actionSheetController: UIAlertController = UIAlertController(title: "Action Sheet", message: "Swiftly Now! Choose an option!", preferredStyle: .ActionSheet)

  //Create and add the Cancel action
  let cancelAction: UIAlertAction = UIAlertAction(title: "Cancel", style: .Cancel) { action -> Void in
    //Just dismiss the action sheet
  }
  actionSheetController.addAction(cancelAction)
    //Create and add first option action
  let takePictureAction: UIAlertAction = UIAlertAction(title: "Take Picture", style: .Default) { action -> Void in
    //Code for launching the camera goes here
    }
  actionSheetController.addAction(takePictureAction)
  //Create and add a second option action
  let choosePictureAction: UIAlertAction = UIAlertAction(title: "Choose From Camera Roll", style: .Default) { action -> Void in
    //Code for picking from camera roll goes here
    }
  actionSheetController.addAction(choosePictureAction)

  //Present the AlertController
  self.presentViewController(actionSheetController, animated: true, completion: nil)
}

Output:

也许它会对你有所帮助。