基本上，我在使用JSON数据创建数组并形成表格视图。
我希望表格单元格通过JSON数组中的字段之一进行分组。
这是JSON数据的样子：
[{"customer":"Customer1","number":"122039120},{"customer":"Customer2","number":"213121423"}]
每个number需要按每个customer分组。
这怎么办？
这是我使用表实现JSON数据的方式：
CustomerViewController.swift
import UIKit
class CustomerViewController: UIViewController, UITableViewDataSource, UITableViewDelegate, FeedCustomerProtocol {
var feedItems: NSArray = NSArray()
var selectedStock : StockCustomer = StockCustomer()
let tableView = UITableView()
@IBOutlet weak var customerItemsTableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
//set delegates and initialize FeedModel
self.tableView.allowsMultipleSelection = true
self.tableView.allowsMultipleSelectionDuringEditing = true
self.customerItemsTableView.delegate = self
self.customerItemsTableView.dataSource = self
let feedCustomer = FeedCustomer()
feedCustomer.delegate = self
feedCustomer.downloadItems()
}
}
func itemsDownloaded(items: NSArray) {
feedItems = items
self.customerItemsTableView.reloadData()
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// Return the number of feed items
print("item feed loaded")
return feedItems.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
// Retrieve cell
let cell = tableView.dequeueReusableCell(withIdentifier: "customerGoods", for: indexPath) as? CheckableTableViewCell
let cellIdentifier: String = "customerGoods"
let myCell: UITableViewCell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier)!
// Get the stock to be shown
let item: StockCustomer = feedItems[indexPath.row] as! StockCustomer
// Configure our cell title made up of name and price
let titleStr = [item.number].compactMap { $0 }.joined(separator: " - ")
return myCell
}
func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath) {
tableView.cellForRow(at: indexPath)?.accessoryType = .none
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.cellForRow(at: indexPath)?.accessoryType = .checkmark
let cellIdentifier: String = "customerGoods"
let myCell: UITableViewCell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier)!
myCell.textLabel?.textAlignment = .left
}
}
FeedCustomer.swift：
import Foundation
protocol FeedCustomerProtocol: class {
func itemsDownloaded(items: NSArray)
}
class FeedCustomer: NSObject, URLSessionDataDelegate {
weak var delegate: FeedCustomerProtocol!
let urlPath = "https://www.example.com/example/test.php"
func downloadItems() {
let url: URL = URL(string: urlPath)!
let defaultSession = Foundation.URLSession(configuration: URLSessionConfiguration.default)
let task = defaultSession.dataTask(with: url) { (data, response, error) in
if error != nil {
print("Error")
}else {
print("stocks downloaded")
self.parseJSON(data!)
}
}
task.resume()
}
func parseJSON(_ data:Data) {
var jsonResult = NSArray()
do{
jsonResult = try JSONSerialization.jsonObject(with: data, options:JSONSerialization.ReadingOptions.allowFragments) as! NSArray
} catch let error as NSError {
print(error)
}
var jsonElement = NSDictionary()
let stocks = NSMutableArray()
for i in 0 ..< jsonResult.count
{
jsonElement = jsonResult[i] as! NSDictionary
let stock = StockCustomer()
//the following insures none of the JsonElement values are nil through optional binding
if let number = jsonElement[“number”] as? String,
let customer = jsonElement["customer"] as? String,
{
stock.customer = customer
stock.number = number
}
stocks.add(stock)
}
DispatchQueue.main.async(execute: { () -> Void in
self.delegate.itemsDownloaded(items: stocks)
})
}
}
StockCustomer.swift：
import UIKit
class StockCustomer: NSObject {
//properties of a stock
var customer: String?
var number: String?
//empty constructor
override init()
{
}
//construct with @name and @price parameters
init(customer: String) {
self.customer = customer
}
override var description: String {
return "Number: \(String(describing: number)), customer: \(String(describing: customer))"
}
}
答案 0 :(得分：0)
您可以通过创建一个数组数组来实现。像这样
[[{"customer": "customer1", "number": "123"}, {"customer": "customer1", "number": "456"}], [{"customer": "customer2", "number": "678"}, {"customer": "customer2", "number": "890"}]]
这不是可用于分组的唯一数据结构。另一种可能性是：
{"customer1": [{"customer": "customer1", "number": "123"}, {"customer": "customer1", "number": "456"}], "customer2": [{"customer": "customer2", "number": "678"}, {"customer": "customer2", "number": "890"}]}
然后，您可以使用UITableView sections按客户分组。节数将是内部数组的数量，每个节将包含与该内部数组中的数字一样多的行。
答案 1 :(得分：0)
您可以使用sequence Dictionary之一基于特定的密钥对initializer进行分组，
init(grouping:by:)
上述方法init将根据您将在其sequence中提供的密钥对给定的closure进行分组。
此外，要解析此类JSON，您可以轻松地使用Codable而不是手动完成所有工作。
因此，首先使StockCustomer符合Codable协议。
class StockCustomer: Codable {
var customer: String?
var number: String?
}
接下来，您可以像这样解析数组：
func parseJSON(data: Data) {
do {
let items = try JSONDecoder().decode([StockCustomer].self, from: data)
//Grouping the data based on customer
let groupedDict = Dictionary(grouping: items) { $0.customer } //groupedDict is of type - [String? : [StockCustomer]]
self.feedItems = Array(groupedDict.values)
} catch {
print(error.localizedDescription)
}
}
在此处详细了解init(grouping:by:)：https://developer.apple.com/documentation/swift/dictionary/3127163-init
使feedItems类型的CustomerViewController中的[[StockCustomer]]对象
现在，您可以通过以下方式实现UITableViewDataSource方法：
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.feedItems.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "customerGoods", for: indexPath) as! CheckableTableViewCell
let items = self.feedItems[indexPath.row]
cell.textLabel?.text = items.compactMap({$0.number}).joined(separator: " - ")
//Configure the cell as per your requirement
return cell
}
尝试用所有零碎的方法来实现该方法，并在遇到任何问题时通知我。