放松后，显示警告继续停止继续。如何确保在展开顺序完成后显示警报？

Question

我有一个从视图控制器到B视图控制器的展开顺序。

网络操作在B完成。操作完成后，响应将显示在视图控制器中。

我成功地做出了这个结构。但有一个问题：

当我尝试显示警报时，它显示但停止了继续。如何在赛季完成后确保提醒节目。

错误是在这里：

2016-04-27 14:39:28.350 PROJECT[9100:128844] Presenting view controllers on detached view controllers is discouraged <PROJECT.FeedTableViewController: 0x7a928c00>. 
2016-04-27 14:39:28.359 PROJECT[9100:128844] popToViewController:transition: called on <UINavigationController 0x7c12a800> while an existing transition or presentation is occurring; the navigation stack will not be updated. 

开卷处理程序在一个：

@IBAction func unwindToFeed(segue: UIStoryboardSegue) { 
     jsonArray[rowFromShare!]["ApplicationDataUsers"] = jsonFromShare! 
     tableView.reloadData() 
     ShowErrorDialog("Success", message: successMessageFromShare!, buttonTitle: "OK") 
    } 

//Error Dialog 
func ShowErrorDialog(title:String, message:String, buttonTitle:String){ 
    let alert = UIAlertController(title: title, message: message, preferredStyle: .Alert) 
    alert.addAction(UIAlertAction(title: "OK", style: .Default) { _ in }) 
    self.presentViewController(alert, animated: true){} 
} 

在乙开卷触发：

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) { 

    if segue.identifier == "unwindToFeed"{ 
     let feedTable = segue.destinationViewController as! FeedTableViewController 
     feedTable.rowFromShare = row 
     feedTable.jsonFromShare = jsonToShare 
     feedTable.successMessageFromShare = successMessageToShare 
    } 

    // Get the new view controller using segue.destinationViewController. 
    // Pass the selected object to the new view controller. 
} 

A = FeedTableViewController B = ShareTableViewController

如何在确定完成后确保显示警报？

Answer 1

unwindToFeed方法在unwind segue完成之前调用，就像您找到的那样。

一种方法是在unwindToFeed方法中设置一个布尔值，然后在viewDidAppear中检查该布尔值，当知道该segue已完成时。如果布尔设置则可以显示警报：

@IBAction func unwindToFeed(segue: UIStoryboardSegue) { 
    jsonArray[rowFromShare!]["ApplicationDataUsers"] = jsonFromShare! 
    tableView.reloadData() 
    self.unwinding = true 
} 

override func viewDidAppear(animated: Bool) { 
    super.viewDidAppear(animated) 
    if (self.unwinding) { 
     self.ShowErrorDialog("Success", message: successMessageFromShare!, buttonTitle: "OK") 
    self.unwinding=false 
    }