嵌入式导航控制器栏不显示

我试图显示另一个具有嵌入式导航控制器的TableViewController。但是，当我尝试运行模拟时，它不显示导航控制器。嵌入式导航控制器栏不显示

我已经附加了一些截图

我的代码AlertTableViewController.swift

override func tableView(tableView: UITableView, editActionsForRowAtIndexPath indexPath: NSIndexPath) -> [AnyObject] { 


    var deleteAction = UITableViewRowAction(style: UITableViewRowActionStyle.Default, 
     title: "Delete",handler: { (action:UITableViewRowAction!, indexPath:NSIndexPath!) -> Void in 
      // Delete the row from the data source 
    }) 



    var editAction = UITableViewRowAction(style: UITableViewRowActionStyle.Default, 
     title: "Edit",handler: { (action:UITableViewRowAction!, indexPath:NSIndexPath!) -> Void in 
      // Delete the row from the data source 

      let wlObject = self.fetchedResultsController.objectAtIndexPath(indexPath) as! AlertScheduleList 

      let editDestinationController = self.storyboard?.instantiateViewControllerWithIdentifier("editWLVC") as! EditWLTableViewController 
      editDestinationController.watchlist = wlObject 
      self.presentViewController(editDestinationController, animated: true, completion: nil) 

    }) 

    editAction.backgroundColor = UIColor(red: 255.0/255.0, green: 126.0/255.0, blue: 0.0/255.0, alpha: 1.0) 
    deleteAction.backgroundColor = UIColor(red: 236.0/255.0, green: 0.0/255.0, blue: 100.0/255.0, alpha: 1.0) 

    return [deleteAction, editAction] 
}

我的故事板的AlertTableViewController

enter image description here