这里的问题是我的表视图中出现重复项，我知道为什么，但我不知道如何修复它并实现不同的系统。
我的应用程序是一个博客阅读器，它使用 PHP 从 MYSQL 数据库读取数据，然后将 JSON 发送到我的 Swift 应用程序。我的表视图有两个部分，第一部分用于数据库中的所有对象，第二部分用于当我单击单元格上的“跟随”按钮时，基本上将对象从 mainArray 移动到 followedArray。每个部分都使用一个数组，例如，我将所有对象从 mainArray 移动到 followArray，然后更新表，我在 mainArray 中再次获取所有这些对象，显然是因为 mainarray 是空的，并且代码只是在执行其工作。
那么，我怎样才能实现一个更好的系统，这样当用户将对象从一个部分移动到另一个部分（或从 mainArray 到 followArray）时，mainArray 就不会重新填充它拥有且现在位于 followArray 中的相同对象。
这是我使用的代码。
MainController.swift - Tableview 所在的类
var mainArray = [Blog]()
var followedArray = [Blog]()
// Title for Header
func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
if !(searchController.isActive && searchController.searchBar.text != "") {
if section == 0 {
return "Followed Blogs"
}
else {
return "All Blogs"
}
}
return "Filtered Blogs"
}
// Number of Rows in Section
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if !(searchController.isActive && searchController.searchBar.text != "") {
if section == 0 {
return followedArray.count
}
else if (section == 1) {
return mainArray.count
}
}
return filteredArray.count
}
// CellForRowAt indexPath
public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let CellIdentifier = "Cell"
var cell = tableView.dequeueReusableCell(withIdentifier: CellIdentifier) as! CustomCell
if cell != cell {
cell = CustomCell(style: UITableViewCellStyle.default, reuseIdentifier: CellIdentifier)
}
// Configuring the cell
var blogObject: Blog
if !(searchController.isActive && searchController.searchBar.text != "") {
if indexPath.section == 0 {
blogObject = followedArray[indexPath.row]
cell.populateCell(blogObject, isFollowed: true, indexPath: indexPath, parentView: self)
}
else if indexPath.section == 1 {
blogObject = mainArray[indexPath.row]
cell.populateCell(blogObject, isFollowed: false, indexPath: indexPath, parentView: self)
}
}
else {
blogObject = filteredArray[indexPath.row]
cell.populateCell(blogObject, isFollowed: false, indexPath: indexPath, parentView: self)
}
return cell
}
// Follow Button
@IBAction func followButtonClick(_ sender: UIButton!) {
// Adding row to tag
let buttonPosition = (sender as AnyObject).convert(CGPoint.zero, to: self.myTableView)
if let indexPath = self.myTableView.indexPathForRow(at: buttonPosition) {
// Showing Status Labels
let cell = self.myTableView.cellForRow(at: indexPath) as! CustomCell
cell.firstStatusLabel.isHidden = false
cell.secondStatusLabel.isHidden = false
// Change Follow to Following
(sender as UIButton).setImage(UIImage(named: "follow.png")!, for: .normal)
cell.followButton.isHidden = true
cell.followedButton.isHidden = false
// Checking wether to import from mainArray or filteredArray to followedArray
if !(searchController.isActive && searchController.searchBar.text != "") {
self.myTableView.beginUpdates()
// ----- Inserting Cell to followedArray -----
followedArray.insert(mainArray[indexPath.row], at: 0)
myTableView.insertRows(at: [IndexPath(row: 0, section: 0)], with: .fade)
// ----- Removing Cell from mainArray -----
mainArray.remove(at: indexPath.row)
let rowToRemove = indexPath.row
self.myTableView.deleteRows(at: [IndexPath(row: rowToRemove, section: 1)], with: .fade)
self.myTableView.endUpdates()
myTableView.reloadData()
// After Updating Table, Save the Archived to UserDefaults
saveUserDefaults()
}
else {
self.myTableView.beginUpdates()
// ----- Inserting Cell to followedArray -----
let blogObject: Blog = filteredArray[indexPath.row]
let indexOfObjectInArray = mainArray.index(of: blogObject)
followedArray.insert(blogObject, at: 0)
// ----- Removing Cell from filteredArray -----
filteredArray.remove(at: indexPath.row)
mainArray.remove(at: indexOfObjectInArray!)
let rowToRemove = indexPath.row
self.myTableView.deleteRows(at: [IndexPath(row: rowToRemove, section: 0)], with: .fade)
self.myTableView.endUpdates()
myTableView.reloadData()
// After Updating Table, Save the Archived to UserDefaults
saveUserDefaults()
}
}
}
// Retrieving Data from Server
func retrieveDataFromServer() {
let getDataURL = "http://example.com/receiving.php"
let url: NSURL = NSURL(string: getDataURL)!
do {
let data: Data = try Data(contentsOf: url as URL)
let jsonArray = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as! NSMutableArray
// Looping through jsonArray
for jsonObject in jsonArray {
if let blog = Blog.createGame(from: jsonObject as AnyObject) {
mainArray.append(blog)
}
}
}
catch {
print("Error: (Retrieving Data)")
}
myTableView.reloadData()
}
Blog.swift - 处理我也使用 NSCoder 的博客对象
import UIKit
class Blog: NSObject, NSCoding {
var blogName: String!
var blogStatus1: String!
var blogStatus2: String!
var blogURL: String!
var blogID: String!
var blogType: String!
var blogDate: String!
var blogPop: String!
static func createBlog(from jsonObject: AnyObject) -> Blog? {
guard let bID: String = jsonObject.object(forKey: "id") as? String,
let bName: String = jsonObject.object(forKey: "blogName") as? String,
let bStatus1: String = jsonObject.object(forKey: "blogStatus1") as? String,
let bStatus2: String = jsonObject.object(forKey: "blogStatus2") as? String,
let bURL: String = jsonObject.object(forKey: "blogURL") as? String,
let bType: String = jsonObject.object(forKey: "blogType") as? String,
let bDate: String = jsonObject.object(forKey: "blogDate") as? String,
let bPop: String = jsonObject.object(forKey: "blogPop") as? String
else {
print("Error: (Creating Blog Object)")
return nil
}
let blog = Blog()
blog.blogName = bName
blog.blogStatus1 = bStatus1
blog.blogStatus2 = bStatus2
blog.blogURL = bURL
blog.blogID = bID
blog.blogType = bType
blog.blogDate = bDate
blog.blogPop = bPop
return blog
}
convenience required init?(coder aDecoder: NSCoder) {
self.init ()
self.blogName = aDecoder.decodeObject(forKey: "blogName") as! String
self.blogStatus1 = aDecoder.decodeObject(forKey: "blogStatus1") as! String
self.blogStatus2 = aDecoder.decodeObject(forKey: "blogStatus2") as! String
self.blogURL = aDecoder.decodeObject(forKey: "blogURL") as! String
self.blogID = aDecoder.decodeObject(forKey: "blogID") as! String
self.blogType = aDecoder.decodeObject(forKey: "blogType") as! String
self.blogDate = aDecoder.decodeObject(forKey: "blogDate") as! String
self.blogPop = aDecoder.decodeObject(forKey: "blogPop") as! String
}
func encode(with aCoder: NSCoder) {
aCoder.encode(blogName, forKey: "blogName")
aCoder.encode(blogStatus1, forKey: "blogStatus1")
aCoder.encode(blogStatus2, forKey: "blogStatus2")
aCoder.encode(blogURL, forKey: "blogURL")
aCoder.encode(blogID, forKey: "blogID")
aCoder.encode(blogType, forKey: "blogType")
aCoder.encode(blogDate, forKey: "blogDate")
aCoder.encode(blogPop, forKey: "blogPop")
}
}
有没有办法在重新填充 mainArray 之前进行检查，以查看 followArray 中的内容以及数据库中缺少或添加的内容以导入而不是创建重复项，因为将添加新博客并且用户将跨部分传输博客，因此这是一个主要问题我有。
感谢您的帮助，因为我仍在学习 Swift，谢谢。
