ios - 谁的 View 不在窗口层次结构中？ swift

Question

我想要显示一个 TableView Controller 。因此，我在下面的 completionwithitemshandler 属性中显示了 View Controller 。

 let activityViewController = UIActivityViewController(activityItems:[memeedimage] , applicationActivities: nil)
        presentViewController(activityViewController, animated: true, completion: nil)

    activityViewController.completionWithItemsHandler = {
        (activity, success, returneditems, error) in
        println("Activity: \(activity) Success: \(success) Items: \(returneditems) Error: \(error)")
        self.save()
        activityViewController.dismissViewControllerAnimated(true, completion: nil)

        let memevc:MemeTableViewController  = MemeTableViewController()
        activityViewController.presentViewController(memevc, animated: true, completion: nil)
    }

但我收到以下运行时错误:

Warning: Attempt to present <MemeMe.MemeTableViewController: 0x7fc4b6179600> on <UIActivityViewController: 0x7fc4b6148180> whose view is not in the window hierarchy!

所以我认为这与我解包具有可选数据类型的 meme 对象有关。

 func save(){
        var meme : MemeObject?
        if let memez = meme{
          meme = MemeObject(textFieldtop : texfieldtop.text! ,textFieldbottom : textfieldbottom.text!  ,image : imagePickerView.image! , memedImage : generateMemedImage())
            (UIApplication.sharedApplication().delegate as! AppDelegate).memes.append(meme!)
        }
        else{
            println("Optionals man")
        }


    }

Answer 1

问题是您正在关闭 UIActivityViewController，然后尝试从中呈现另一个 View Controller 。相反，你想要的是从你展示事件 View Controller 的同一个 View Controller 展示你的新 View Controller 。

例如，您可以在 Activity View Controller dismiss 完成后呈现新的 View Controller:

let activityViewController = UIActivityViewController(activityItems:[memeedimage] , applicationActivities: nil)
        presentViewController(activityViewController, animated: true, completion: nil)


    activityViewController.completionWithItemsHandler = {
        (activity, success, returneditems, error) in
        println("Activity: \(activity) Success: \(success) Items: \(returneditems) Error: \(error)")
        self.save()
        activityViewController.dismissViewControllerAnimated(true, completion: {
           let memevc:MemeTableViewController  = MemeTableViewController()
        self.presentViewController(memevc, animated: true, completion: nil)
})

注意:在您最初的“presentViewController”中，您不需要使用 self.presentViewController()，但是因为新调用是在一个使用 self.presentViewController() 的 block 内，所以它明确表明应该由 self 呈现它。