小编nvi*_*ens的帖子

当我尝试以编程方式显示弹出视图控制器时,它将无法工作,我不知道为什么.我已经从网上的多个来源复制,似乎没有任何工作,每次显示Warning: Attempt to present <AddFriendsPopoverViewController> on <MainPageViewController> whose view is not in the window hierarchy! 我迷路了,我在控制台中得到同样的错误,似乎无法弄清问题是什么,提前感谢!

这是我的viewDidLoad()函数中的快速代码:

let addFriendsPopoverViewController = AddFriendsPopoverViewController()

override func viewDidLoad() {
    super.viewDidLoad()

    if (PFUser.currentUser()?["numberOfFriends"])! as! NSObject == 0 {
        print(PFUser.currentUser()?["numberOfFriends"])

        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        let vc = storyboard.instantiateViewControllerWithIdentifier("AddFriendsPopoverViewController") as! UIViewController

        vc.modalPresentationStyle = UIModalPresentationStyle.Popover
        vc.preferredContentSize = CGSizeMake(50, 50)
        let popoverMenuViewController = vc.popoverPresentationController
        popoverMenuViewController!.permittedArrowDirections = .Any
        popoverMenuViewController!.delegate = self
        popoverMenuViewController!.sourceView = self.view
        popoverMenuViewController!.sourceRect = CGRectMake(
            100,
            100,
            0,
            0)

    self.presentViewController(vc, animated: true, …