ios - 关闭模态视图 Controller 后 TableView 数据加载多次

Question

我有一个显示来自 Parse 的对象的 TableView 。我有一个按钮，它以模态方式呈现另一个用于添加新对象的 View Controller 。当表格 View 中的一行被选中时，它会以模态方式呈现一个 View Controller 来显示对象信息并允许编辑对象。我遇到的问题是，当我添加一个新项目或编辑一个项目然后关闭模态 Controller 时，表格 View 会重新加载并多次显示数据。我做错了什么？

这些函数在呈现 View Controller (我的 TableView Controller )中。显然问题必须在 didDismissViewController() 中。

func getItems() {
        // activityIndicator?.startAnimating()

        let query = PFQuery(className: "Items")
        query.whereKey("user", equalTo: PFUser.currentUser()!)
        query.whereKey("collection", equalTo: self.title!)
        query.orderByAscending("item")
        query.limit = limit
        query.skip = skip
        query.findObjectsInBackgroundWithBlock( {
            (objects, error) -> Void in
            if error == nil {
                if let objects = objects as [PFObject]! {
                    for object in objects {
                        self.itemNames.append(object["item"] as! String)
                        self.objectID.append(object.objectId!)
                        self.itemUPC.append(object["upc"] as! String)
                        self.model.append(object["model"] as! String)
                        self.pricePaid.append(object["pricePaid"] as! String)
                        // self.imagesArray.append(object["images"])
                        if object["images"] == nil {
                            self.imagesArray.append(nil)
                        } else {
                            self.imagesArray.append(object["images"])
                        }
                    }
                }
                // print(self.imagesArray)

                /*
                if objects!.count == self.limit {
                self.skip += self.limit
                self.getCollections()
                }
                */

                dispatch_async(dispatch_get_main_queue()) {
                    self.tableView.reloadData()
                    // self.activityIndicator!.stopAnimating()
                    print(self.itemNames)
                }
            } else {
                var errorString = String()
                if let message = error!.userInfo["error"] {
                    errorString = message as! String
                }

                print(errorString)
            }
        })
    }

    func createItem() {
        let createVC = CreateItemViewController(nibName: "CreateItemViewController", bundle: nil)
        let navController = NavController(rootViewController: createVC)
        navController.modalPresentationStyle = .OverCurrentContext
        createVC.collectionString = self.title!
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "didDismissViewController", name: "ItemAdded", object: nil)
        self.presentViewController(navController, animated: true, completion: nil)
    }

    func didDismissViewController() {
        objectID.removeAll()
        itemNames.removeAll()
        itemUPC.removeAll()
        pricePaid.removeAll()
        model.removeAll()
        imagesArray.removeAll()
        itemImages.removeAll()
        getItems()
    }

此函数位于以模式呈现的 View Controller 中，您可以在其中输入要创建的 Parse 对象的项目详细信息。

func done() {
        // Save the item data...

        if itemImageView.image != nil {
            let pictureData = UIImageJPEGRepresentation(itemImageView.image!, 0.05)
            image = PFFile(name: "img", data: pictureData!)
        } else {
            image = nil
        }

        let newItem = PFObject(className: "Items")
        newItem["item"] = itemNameTextField.text
        newItem["upc"] = upcTextField.text
        newItem["model"] = modelTextField.text
        newItem["pricePaid"] = pricePaidTextField.text
        newItem["user"] = PFUser.currentUser()
        newItem["collection"] = collectionString
        newItem["images"] = itemImages 

        newItem.saveInBackgroundWithBlock( {
            (succeeded, error) -> Void in
            if error == nil {
                NSNotificationCenter.defaultCenter().postNotificationName("ItemAdded", object: nil, userInfo: nil)
                self.presentingViewController?.dismissViewControllerAnimated(true, completion: nil)
            } else {
                var alert: UIAlertController?
                let errorOK = UIAlertAction(title: "OK", style: .Default, handler: {
                    (action) -> Void in
                    alert?.dismissViewControllerAnimated(true, completion: nil)
                })
                var errorString = String()
                if let message = error!.userInfo["error"] {
                    errorString = message as! String
                }
                alert = UIAlertController(title: "Error", message: errorString, preferredStyle: .Alert)
                alert!.addAction(errorOK)
                self.presentViewController(alert!, animated: true, completion: nil)
            }
        })
    }

Answer 1

看来您正在添加您的观察者，而不是删除它们。