编辑1：对象声明（转到帖子的底部）
我正在从JSON（通过我的API下载）加载数据，并且出于某种原因，在过去的几天里，我已经将单元格显示为空，在完美构建的单元格与实际之间数据。如何让那些空单元格自动消失？ （所以细胞之间没有间隙）？
这是我的代码，我从JSON和我的数据源代码创建对象：
对象代码：
func populateCurrentIssue() {
if populatingCurrentIssue {
return
}
populatingCurrentIssue = true
self.cellLoadingIndicator.backgroundColor = UIColor.yellowColor()
self.cellLoadingIndicator.startAnimating()
Alamofire.request(GWNetworking.Router.Issue).responseJSON() { response in
if let JSON = response.result.value {
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0)) {
var nodeIDArray : [Int]
if (JSON .isKindOfClass(NSDictionary)) {
for node in JSON as! Dictionary<String, AnyObject> {
let nodeIDValue = node.0
var lastItem : Int = 0
if let issueElement : IssueElement = IssueElement(title: "Could not retrieve title", nodeID: 0, timeStamp: 0, imageURL: "init", author: "Author not found", issueNumber: "Issue # error", volumeNumber: "Volume # error", articleContent: "Could not retrieve article content", coverImageInteger: "init", coverImage: UIImage()) {
issueElement.title = node.1["title"] as! String
issueElement.nodeID = Int(nodeIDValue)!
let timeStampString = node.1["revision_timestamp"] as! String
issueElement.timeStamp = Int(timeStampString)!
issueElement.imageURL = String(node.1["image_url"])
if let author = node.1["author"] as? String {
issueElement.author = author
}
issueElement.volumeNumber = String(node.1["volume_int"])
if let articleContent = node.1["html_content"] as? String {
issueElement.articleContent = articleContent
}
issueElement.coverImageInteger = String(node.1["cover_image"]) // addition specific to the Current Issue View Controller
lastItem = self.currentIssueObjects.count
print(issueElement.nodeID)
self.currentIssueObjects.addObject(issueElement)
let timestampSortDescriptor = NSSortDescriptor(key: "timeStamp", ascending: false)
self.currentIssueObjects.sortUsingDescriptors([timestampSortDescriptor])
let coverImageSortDescriptor = NSSortDescriptor(key: "coverImageInteger", ascending: false)
self.currentIssueObjects.sortUsingDescriptors([coverImageSortDescriptor])
print(self.currentIssueObjects)
let indexPaths = (lastItem..<self.currentIssueObjects.count).map {
NSIndexPath(forItem: $0, inSection: 0) }
}
}
}
dispatch_async(dispatch_get_main_queue()) {
self.currentIssueTableView.reloadData()
self.cellLoadingIndicator.stopAnimating()
self.cellLoadingIndicator.hidesWhenStopped = true
}
}
}
self.populatingCurrentIssue = false
}
}
数据源代码：
override func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell {
let row = indexPath.row
guard let cell = tableView.dequeueReusableCellWithIdentifier(CurrentIssueArticlesTableCellIdentifier, forIndexPath: indexPath) as? CurrentIssueArticlesTableViewCell else {
print ("error: currentIssueTableView cell is not of class CurrentIssueArticlesTableViewCell, we will use EditorialsTableViewCell instead")
return tableView.dequeueReusableCellWithIdentifier(CurrentIssueArticlesTableCellIdentifier, forIndexPath: indexPath) as! EditorialsTableViewCell
}
let currentIssueObject = currentIssueObjects.objectAtIndex(indexPath.row) as! IssueElement
let title = currentIssueObject.title ?? ""
let timeStampDateObject = NSDate(timeIntervalSince1970: NSTimeInterval(currentIssueObject.timeStamp))
let timeStampDateString = dateFormatter.stringFromDate(timeStampDateObject) ?? "Date unknown"
if let author = currentIssueObject.author {
cell.currentIssueArticlesAuthorLabel!.font = UIFont.preferredFontForTextStyle(UIFontTextStyleSubheadline)
cell.currentIssueArticlesAuthorLabel!.text = author
} else {
}
let issueNumber = currentIssueObject.issueNumber ?? ""
let volumeNumber = currentIssueObject.volumeNumber ?? ""
let articleContent = currentIssueObject.articleContent ?? ""
let nodeID = currentIssueObject.nodeID ?? 0
cell.currentIssueArticlesHeadlineLabel.font = UIFont.preferredFontForTextStyle(UIFontTextStyleHeadline)
cell.currentIssueArticlesHeadlineLabel.text = title
cell.currentIssueArticlesPublishDateLabel.font = UIFont.preferredFontForTextStyle(UIFontTextStyleSubheadline)
cell.currentIssueArticlesPublishDateLabel.text = timeStampDateString
if row == 0 {
cell.userInteractionEnabled = false
let imageURL = (currentIssueObjects.objectAtIndex(row) as! IssueElement).imageURL
cell.currentIssueArticlesHeadlineLabel.textColor = UIColor.clearColor()
cell.currentIssueArticlesAuthorLabel.textColor = UIColor.clearColor()
cell.currentIssueArticlesPublishDateLabel.textColor = UIColor.clearColor()
cell.request?.cancel()
if let image = self.imageCache.objectForKey(imageURL!) as? UIImage {
cell.currentIssueArticlesBackgroundImageView.image = image
} else {
cell.currentIssueArticlesBackgroundImageView.image = UIImage(named: "reveal Image")
cell.request = Alamofire.request(.GET, imageURL!).responseImage() { response in
if response.result.error == nil && response.result.value != nil {
self.imageCache.setObject(response.result.value!, forKey: response.request!.URLString)
cell.currentIssueArticlesBackgroundImageView.image = response.result.value
} else {
}
}
}
}
else {
}
if (cell.currentIssueArticlesAuthorLabel == nil) {
tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: UITableViewRowAnimation.Automatic)
}
return cell
}
编辑1：对象声明
class IssueElement: NSObject {
var title: String // title
var nodeID: Int // nid
var timeStamp: Int // revision_timestamp
var imageURL: String? // image_url
var author: String? // author
var issueNumber: String // issue_int
var volumeNumber: String // volume_int
var articleContent: String // html_content
var coverImageInteger: String // Variable that indicates whether this is the cover page or not (1 for cover, 0 for everything else)
var coverImage: UIImage
init(title: String, nodeID: Int, timeStamp: Int, imageURL: String?, author: String, issueNumber: String, volumeNumber: String, articleContent: String, coverImageInteger: String, coverImage: UIImage) {
self.title = title
self.nodeID = nodeID
self.timeStamp = timeStamp
self.imageURL = imageURL
self.author = author
self.issueNumber = issueNumber
self.volumeNumber = volumeNumber
self.articleContent = articleContent
self.coverImageInteger = coverImageInteger
self.coverImage = coverImage
}
override func isEqual(object: AnyObject!) -> Bool {
return (object as! IssueElement).nodeID == self.nodeID
}
override var hash: Int {
return (self as IssueElement).nodeID
}
}
答案 0 :(得分：1)
实际上你不想这样做，因为途中还会有其他问题。例如，编辑单元格中数据的最简单方法是将单元格的indexPath.row链接到dataSource（例如，第二个单元格链接到dataSource中的第二个元素，第三个链接到第三个元素，依此类推）。如果您过滤单元格而不是数据，那么您将打破这种逻辑。
因此，最好的方法是过滤数据，只需在将空元素添加到UITableView之前删除它们。
答案 1 :(得分：0)
我同意Lithium的初步分析。在将数据添加到数组之前先过滤数据。如果数据是字符串，那么可以在添加到数组之前尝试字符计数验证，如下所示：
if issueElement.characters.count > 0 { //Add to Array... }