Question

我正在创建一个可以发布消息的应用。我将数据存储在Firebase中。当我发布新消息时，该特定单元格多次重复（因此我看到帖子有2,3,4次或更多次）。但它只是Firebase中的一篇文章。当我刷新屏幕时（例如对数据进行排序），它只会再次发布一个帖子。我做错了什么？

这是我的相关代码：

generate_series

按日期排序数据：

    override func viewDidLoad() {
    super.viewDidLoad()

    DataService.ds.REF_POSTS.observeEventType(.Value, withBlock:  { snapshot in
        let sortByDate = NSUserDefaults.standardUserDefaults().boolForKey("sortByDate")
        if sortByDate == true {
            self.sortingByDate()
            self.tableView.reloadData()
        } else {
            self.sortingByLikes()
            self.tableView.reloadData()
        }
    })
}

按喜欢排序数据：

func sortingByDate() {
    NSUserDefaults.standardUserDefaults().setBool(true, forKey: "sortByDate")
    sortDateBtn.setTitleColor(UIColor(red: 255/255, green: 102/255, blue: 102/355, alpha: 1.0), forState: .Normal)
    sortLikeBtn.setTitleColor(UIColor(red: 76/255, green: 76/255, blue: 76/355, alpha: 1.0), forState: .Normal)

    if (searchController.active) {
        self.posts = []
        DataService.ds.REF_POSTS.queryOrderedByChild("timestamp").observeEventType(.ChildAdded, withBlock: { snapshot in
            if let postDict = snapshot.value as? Dictionary<String, AnyObject> {
                let key = snapshot.key
                let post = Post(postKey: key, dictionary: postDict)
                self.posts.insert(post, atIndex: 0)
            }
            if let searchText = self.searchController.searchBar.text {
                self.filterContent(searchText)
                self.tableView.reloadData()
            }
        })
    } else {
        self.posts = []
        DataService.ds.REF_POSTS.queryOrderedByChild("timestamp").observeEventType(.ChildAdded, withBlock: { snapshot in
            if let postDict = snapshot.value as? Dictionary<String, AnyObject> {
                let key = snapshot.key
                let post = Post(postKey: key, dictionary: postDict)
                self.posts.insert(post, atIndex: 0)
            }
            self.tableView.reloadData()
        })
    }
}

发布到Firebase：

func sortingByLikes() {
    NSUserDefaults.standardUserDefaults().setBool(false, forKey: "sortByDate")
    sortLikeBtn.setTitleColor(UIColor(red: 255/255, green: 102/255, blue: 102/355, alpha: 1.0), forState: .Normal)
    sortDateBtn.setTitleColor(UIColor(red: 76/255, green: 76/255, blue: 76/355, alpha: 1.0), forState: .Normal)

    if (searchController.active) {
        self.posts = []
        DataService.ds.REF_POSTS.queryOrderedByChild("likes").observeEventType(.ChildAdded, withBlock: { snapshot in
            if let postDict = snapshot.value as? Dictionary<String, AnyObject> {
                let key = snapshot.key
                let post = Post(postKey: key, dictionary: postDict)
                self.posts.insert(post, atIndex: 0)
            }
            if let searchText = self.searchController.searchBar.text {
                self.filterContent(searchText)
                self.tableView.reloadData()
            }
        })
    } else {
        self.posts = []
        DataService.ds.REF_POSTS.queryOrderedByChild("likes").observeEventType(.ChildAdded, withBlock: { snapshot in
            if let postDict = snapshot.value as? Dictionary<String, AnyObject> {
                let key = snapshot.key
                let post = Post(postKey: key, dictionary: postDict)
                self.posts.insert(post, atIndex: 0)
            }
            self.tableView.reloadData()
        })
    }
}

泰伯维：

func postToFirebase(imgUrl: String?) {
    let imageForProfile = NSUserDefaults.standardUserDefaults().valueForKey("profileImage")
    var post: Dictionary<String, AnyObject> = [
        "title": titleTextField.text!,
        "description": descriptionTextField.text!,
        "likes": 0,
        "location": locationTextField.text!,
        "username": usernameDisplay.text!,
        "uid": NSUserDefaults.standardUserDefaults().valueForKey(KEY_UID)!,
        "img": String(imageForProfile!),
        "timestamp": NSDate.timeIntervalSinceReferenceDate(),
        "lat": lat,
        "long": long,
        ]

        if imgUrl != nil {
            post["imageUrl"] = imgUrl
        }

let firebasePost = DataService.ds.REF_POSTS.childByAutoId()
let url = NSURL(fileURLWithPath: "\(firebasePost)")
let lastComponent = url.lastPathComponent

    if lastComponent != nil {
        post["postKey"] = lastComponent!
    }

firebasePost.setValue(post)

titleTextField.text = ""
descriptionTextField.text = ""
locationTextField.text = ""
imageField.image = UIImage(named: "camera")
imageSelected = false

NSUserDefaults.standardUserDefaults().setBool(true, forKey: "sortByDate")
}

我的cell.configurecell实现：

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    if let cell = tableView.dequeueReusableCellWithIdentifier("PostCell") as? PostCell {
        let postList = searchController.active ? searchResult[indexPath.row] : posts[indexPath.row]
        let post = postList
        cell.request?.cancel()

        var image: UIImage?
        if let url = post.postImgUrl {
            image = FeedVC.imageCache.objectForKey(url) as? UIImage
        }

        var image2: UIImage?
        if let url2 = post.userImgUrl {
            image2 = FeedVC.imageCache.objectForKey(url2) as? UIImage
        }

        cell.configureCell(post, img: image, img2: image2)

        return cell
    } else {
        return PostCell()
    }
}

感谢您的帮助！

Answer 1

由于您使用的是委托方法tableView.dequeueReusableCellWithIdentifier，因此当您请求新单元格时，如果不使用新数据更新新单元格，则会带来包含旧数据的单元格。确保我需要查看您的cell.configureCell实施。

发布到Firebase时，单元格会重复多次

1 个答案: