我正在尝试通过Swift 5中的HTTP get方法从API提取数据。它在启动时成功加载了数据，但是当我刷新页面时，它说“索引超出范围”，这是因为数据是不再会在我的日志中读取，因此索引中没有任何内容。这是一个常见问题，还是仅与我有关？我在下面附加了我的代码，并突出显示了错误出现的位置。谢谢!
import UIKit
import Foundation
class TheClass: UIViewController, UITableViewDataSource, UITableViewDelegate {
@IBOutlet weak var pageView: UITableView!
struct StocksObject {
var volume: String?
}
struct Response: Codable {
let _type: String?
let readLink: String?
let totalEstimatedMatches: Int?
let value: [Value]?
}
struct QueryContext: Codable {
let originalQuery: String?
let adultIntent: Bool?
}
struct Value: Codable {
let name: String?
}
var stocks_object = [StocksObject]()
var news_object = [Value]()
override func viewDidAppear(_ animated: Bool) {
self.news_object.removeAll()
self.getNews()
}
override func viewDidLoad() {
super.viewDidLoad()
getData()
getNews()
pageView.delegate = self
pageView.dataSource = self
}
func getNews() {
let request = NSMutableURLRequest(url: NSURL(string: "https://example.com")! as URL,
cachePolicy: .useProtocolCachePolicy,
timeoutInterval: 10.0)
request.httpMethod = "GET"
request.allHTTPHeaderFields = headers
URLSession.shared.dataTask(with: request as URLRequest) { (data, response, error) in
guard let data = data else { return }
do {
let obj: Response = try JSONDecoder().decode(Response.self, from: data)
let json = try JSONSerialization.jsonObject(with: data, options: [])
print(json)
let objectReview = Value(name: obj.value?[0].name)
self.news_object.append(objectReview)
print("\(String(describing: obj.value?[0].name))")
print("\(String(describing: obj.value?[2].name))")
} catch {
print("ERROR: \(error)")
self.performSegue(withIdentifier: "InvalidSymbol", sender: nil)
}
}.resume()
}
func getData() {
let url = URL(string: "https://example2.com")!
var request = URLRequest(url: url)
request.httpMethod = "GET"
NSURLConnection.sendAsynchronousRequest(request, queue: OperationQueue.main) {
(response, data, error) in
if let data = data {
do {
let json = try JSONDecoder().decode(Root.self,from: data)
let Volume = json.data.first?.volume
struct Root: Codable {
let data: [Datum]
}
struct Datum: Codable {
let volume: String
}
print(json)
let object = StocksObject(volume: Volume)
self.stocks_object.append(object)
DispatchQueue.main.async {
self.pageView.reloadData()
}
} catch {
print(error)
}
}
}
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 825
}
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return stocks_object.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell") as! StockCell
let object = stocks_object[indexPath.row]
//Error is coming in here:
let objectNews = news_object[indexPath.row]
cell.volume.text = object.volume
cell.newsOne.text = objectNews.name
return cell
}
}
最佳答案
在viewDidAppear内部，您需要在页面加载时清空“news_object”数组，然后在viewDidAppear内部调用self.getNews()。
内部viewDidAppear:
self.news_object.removeAll()
self.getNews()
由于您已编辑问题，因此这是您遇到此错误的原因。
对于上面的代码，您需要创建switch语句来检查要返回的array.count并在cellForRowAt中执行相同的操作。因为它们都有不同的长度，这就是您面临错误“超出范围”的原因
我希望现在就清楚了。
关于ios - 第二次API调用后应用崩溃(快速)，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/60936203/