如何解决tableviewController 分页两次从服务器检索我的数据，但并非所有数据都从服务器检索
我有一个包含 3 个单元格的 tableviewController，一个用于从服务器获取图像和文本，第二个用于仅获取文本，第三个用于使用活动指示器实现分页，如下图所示 the 3 cells image
这是分页的响应：
{
"statusCode": 200,"message": "Success","data": {
"result": [
{
"id": 28,"profileId": 12,"creatorId": 8,"postText": "اهلا وسهلا","commentsCount": 0,"interactionsCount": 0,"createdAt": "2021-03-06T15:45:24.756Z","updatedAt": "2021-03-06T15:45:24.756Z","profile": {
"id": 12,"logo": "https://onebusinessqrcode.s3.us-east-2.amazonaws.com/b562b93c-e278-5027-b615-edd399878c1a.jpg","name": "abdallah eslah","category": "Ecommerce","subCategory": "ElectronicMarket"
},"creator": {
"id": 8,"image": "https://onebusinessqrcode.s3.us-east-2.amazonaws.com/0d362ee3-78e3-584a-8c34-6a91afa9dbda.png","email": "abdallaheslah@yahoo.com","mobile": "201094339599"
},"media": [
{
"id": 396,"postId": 28,"media": "https://onebusinessqrcode.s3.us-east-2.amazonaws.com/2ad0ce30-a387-5c73-846a-eb414108fb72.jpg","createdAt": "2021-03-06T15:45:25.438Z","updatedAt": "2021-03-06T15:45:25.438Z"
}
]
},{
"id": 5,"postText": "My new product","commentsCount": 2,"createdAt": "2021-03-01T07:13:39.400Z","updatedAt": "2021-03-01T07:17:15.905Z","media": [
{
"id": 395,"postId": 5,"media": "https://onebusinessqrcode.s3.us-east-2.amazonaws.com/74c28cd0-47be-5053-85ca-c887cc36c781.jpg","createdAt": "2021-03-01T07:13:40.377Z","updatedAt": "2021-03-01T07:13:40.377Z"
}
]
}
],"thisPage": 1,"allPages": 1,"count": 2
}
}
所以我在下面的请求中使用它们来获取数据并实现分页：
//Used Variables in the request
var posts = [Posts]()
var pictures = [UIImage]()
//Pagination Vars
var allPages = 1
var thisPage = 1
override func viewDidLoad() {
super.viewDidLoad()
self.refreshControl = UIRefreshControl()
self.refreshControl?.addTarget(self,action: #selector(refreshData),for: .valueChanged)
self.refreshData()
}
// MARK: - List All Posts
@objc func refreshData(){
thisPage = 1
loadPosts(page: 1,refresh: true)
}
@objc func loadPosts(page: Int,refresh: Bool = false) {
if refresh {
refreshControl?.beginRefreshing()
}
let profileId = UserDefaults.standard.value(forKey: "id") as? Int ?? 0
var urlBuilder?.queryItems = [
URLQueryItem(name: "profileId",value:"\(profileId)"),URLQueryItem(name: "page",value:"\(page)")
]
guard let url = urlBuilder?.url else { return }
var request = URLRequest(url: url)
let token = UserDefaults.standard.value(forKey: "token") as? String ?? ""
request.httpMethod = "GET"
request.setValue(token,forHTTPHeaderField: "x-auth-token")
// send request
URLSession.shared.dataTask(with: request) { (data,response,error) in
DispatchQueue.main.async {
if refresh {
self.posts.removeAll()
self.refreshControl?.endRefreshing()
}
// error occured
if error != nil {
Helper().showAlert(title: "Server Error",message: error!.localizedDescription,in: self)
return
}
do {
// access data - safe mode
guard let data = data else {
Helper().showAlert(title: "Data Error",in: self)
return
}
// converting data to JSON
let json = try JSONSerialization.jsonObject(with: data,options: .allowFragments) as? NSDictionary
guard let parsedJSON = json else {
print("Parsing Error")
return
}
if let data = parsedJSON["data"] as? NSDictionary {
self.allPages = data["allPages"] as? Int ?? 1
let object = Posts()
object.allPages = self.allPages
if let posts = data["result"] as? [NSDictionary] {
for item in posts {
if let interactionsCount = item["interactionsCount"] as? Int {
object.interactionsCount = interactionsCount
}
if let commentCounts = item["commentsCount"] as? Int {
object.commentCounts = commentCounts
}
if let postMedia = item["media"] as? [NSDictionary] {
if postMedia.count > 0 {
let icon_images = postMedia
object.multiImageIcon = icon_images
// self.multiImages_Icon.isHidden = false
if let media = postMedia[0]["media"] as? String {
object.image = media
}
}
}
if let profile = item["profile"] as? NSDictionary {
if profile.count > 0 {
if let name = profile["name"] as? String {
object.name = name
}
if let logo = profile["logo"] as? String {
object.ava = logo
}
}
}
object.text = item["postText"] as? String
object.name = item["name"] as? String
object.date = item["createdAt"] as? String
object.id = item["id"] as? Int
object.ava = item["logo"] as? String
object.commentCounts = item["commentsCount"] as? Int
object.interactionsCount = item["interactionsCount"] as? Int
object.allPages = item["allPages"] as? Int
self.posts.append(object)
self.tableView.reloadData()
}
}
}
} catch {
Helper().showAlert(title: "JSON Error",message: error.localizedDescription,in: self)
return
}
}
}.resume()
}
最后是自定义数据源：
// MARK: - 表视图数据源
override func tableView(_ tableView: UITableView,numberOfRowsInSection section: Int) -> Int {
return posts.count
}
override func tableView(_ tableView: UITableView,cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if thisPage < allPages && indexPath.row == posts.count - 1 {
let cell = tableView.dequeueReusableCell(withIdentifier: "loading")
return cell!
}else {
let pictureUrl = posts[indexPath.row].image ?? ""
if pictureUrl.isEmpty == true {
//5)=> accessing the text cell from main.storyboard
let cell = tableView.dequeueReusableCell(withIdentifier: "NoPicCell",for: indexPath) as! NoPicCell
cell.fullNameLabel.text = posts[indexPath.row].name?.capitalized ??
UserDefaults.standard.value(forKey: "name") as? String
cell.fullNameLabel.textColor = .label
let postText = posts[indexPath.row].text
cell.postTextLabel.text = postText
cell.postTextLabel.textColor = .label
let dateString = posts[indexPath.row].date
let formatterGet = DateFormatter()
formatterGet.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSZ"
let date = formatterGet.date(from: dateString ?? "")
let formatterShow = DateFormatter()
formatterShow.dateFormat = "MMMM dd yyyy - HH:mm"
cell.dateLabel.text = formatterShow.string(from: date ?? Date())
let postStars = posts[indexPath.row].interactionsCount ?? 0
cell.starCountTwo.text = "\(postStars )"
cell.starCountTwo.textColor = .label
let postComments = posts[indexPath.row].commentCounts ?? 0
cell.commentCountOne.text = "\(postComments)"
cell.commentCountOne.textColor = .label
let avaPath = UserDefaults.standard.value(forKey: "logo") as? String
let ava = posts[indexPath.row].ava
Helper().downloadImage(from: (ava ?? avaPath)!,showIn: cell.avaImageViewNoPic,orShow: "user.png")
// Rounded corners
cell.avaImageViewNoPic.layer.cornerRadius = cell.avaImageViewNoPic.frame.width / 2
cell.avaImageViewNoPic.clipsToBounds = true
cell.commentsButton.tag = indexPath.row
cell.starButtonTwo.tag = indexPath.row
cell.optionButton.tag = indexPath.row
pictures.append(UIImage())
return cell
} else {
let cell = tableView.dequeueReusableCell(withIdentifier: "PicCell",for: indexPath) as! PicCell
let postText = posts[indexPath.row].text
cell.postTextLabel.text = postText
cell.postTextLabel.textColor = .label
cell.fullNameLabel.text = posts[indexPath.row].name?.capitalized ?? UserDefaults.standard.value(forKey: "name") as? String
cell.fullNameLabel.textColor = .label
let dateString = posts[indexPath.row].date
let formatterGet = DateFormatter()
formatterGet.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSZ"
let date = formatterGet.date(from: dateString!)
let formatterShow = DateFormatter()
formatterShow.dateFormat = "MMMM dd yyyy - HH:mm"
cell.dateLabel.text = formatterShow.string(from: date!)
let postStars = posts[indexPath.row].interactionsCount ?? 0
cell.starCountPic.text = "\(postStars )"
cell.starCountPic.textColor = .label
let postComments = posts[indexPath.row].commentCounts ?? 0
cell.commentCountOne.text = "\(postComments)"
cell.commentCountOne.textColor = .label
let ava = posts[indexPath.row].ava
let avaPath = UserDefaults.standard.value(forKey: "logo") as? String
Helper().downloadImage(from: (ava ?? avaPath)!,showIn: cell.avaImageViewPic,orShow: "user.png")
// Rounded corners
cell.avaImageViewPic.layer.cornerRadius = cell.avaImageViewPic.frame.width / 2
cell.avaImageViewPic.clipsToBounds = true
cell.commentsButton.tag = indexPath.row
cell.starButtonTwo.tag = indexPath.row
cell.optionButton.tag = indexPath.row
let pictureString = posts[indexPath.row].image
let pictureURL = URL(string: pictureString ?? "")
cell.pictureImageView.kf.setImage(with: pictureURL)
if timelinePosts.count != pictures.count {
}else{
print("Pic cashed")
DispatchQueue.main.async {
}
}
cell.commentsButton.tag = indexPath.row
cell.starButtonTwo.tag = indexPath.row
cell.optionButton.tag = indexPath.row
return cell
}
}
}
willDisplay 方法：
override func tableView(_ tableView: UITableView,willDisplay cell: UITableViewCell,forRowAt indexPath: IndexPath) {
if thisPage < allPages && indexPath.row == posts.count - 1 {
thisPage = thisPage + 1
loadPosts(page: thisPage,refresh: false)
}
}
解决方法
将重载行移出 for 循环
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