swift - 表格 View 的API，添加数值和添加列，每10秒刷新一次表格

Question

因此，我一直在尝试从股票市场的 API 获取数据，我希望每 10-15 秒刷新一次。API 是“https://bittrex.com/api/v1.1/public/getmarketsummaries”。我显示了名称，但是当我必须显示小数点“Last”时，我无法在此处显示它:

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: 
IndexPath) -> UITableViewCell {

let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for:indexPath)

    let item = self.listData[indexPath.row]
    cell.textLabel?.text = item["MarketName"] as? String
    cell.detailTextLabel?.text = item["Last"] as? String
    print(self.listData.count)

    return cell
}

1. 我想从 API 添加一个显示“高”、“低”的列。
2. 我希望它每 10-15 秒刷新一次。

我需要更多关于这个项目的帮助。我是一名化学工程师，但想实现我的想法并开始自己编码。如果您能通过我的电子邮件 (siddhantmehandru@gmail.com) 与我联系，我将不胜感激。我也准备好补偿这项工作了:)

顺便说一句，这里是完整的代码:

import UIKit
var listData = [[String : AnyObject]]()

class DemoJsonTableViewController: UITableViewController {

var listData = [[String : AnyObject]]()

override func viewDidLoad() {
    super.viewDidLoad()

    let url:String = "https://bittrex.com/api/v1.1/public/getmarketsummaries"

    let urlRequest = URL(string: url)

    URLSession.shared.dataTask(with: urlRequest!) { (data, response, error) in
        if(error != nil){
            print(error.debugDescription)
        }
        else{
            do{
                var response = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as! [String:AnyObject]
                self.listData = response["result"] as! [[String:AnyObject]]
                DispatchQueue.main.async {
                    self.tableView.reloadData()
                }
            }catch let error as NSError{
                print(error)
            }
        }
        }.resume()
    // Uncomment the following line to preserve selection between presentations
    // self.clearsSelectionOnViewWillAppear = false

    // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
    // self.navigationItem.rightBarButtonItem = self.editButtonItem()
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

// MARK: - Table view data source

override func numberOfSections(in tableView: UITableView) -> Int {
    // #warning Incomplete implementation, return the number of sections
    return 1
}

override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    // #warning Incomplete implementation, return the number of rows
    return self.listData.count
}


override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)

   let item = self.listData[indexPath.row]
    cell.textLabel?.text = item["MarketName"] as? String
    cell.detailTextLabel?.text = item["Last"] as? String
    print(self.listData.count)

    return cell
}
}

谢谢!

Answer 1

试试这个:

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: 
IndexPath) -> UITableViewCell {

let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for:indexPath)

    let item = self.listData[indexPath.row]
    cell.textLabel?.text = item["MarketName"] as? String
    let lastValue = item["Last"] as? NSNumber
    cell.detailTextLabel?.text = lastValue?.stringValue
    print(self.listData.count)

    return cell
}

override func viewDidLoad() {
    super.viewDidLoad()
    timer = Timer.scheduledTimer(timeInterval: 10, target: self,   selector: (#selector(self.sendUpdateRequest)), userInfo: nil, repeats: true)
}

每 10 秒后将重复调用的函数。

func sendUpdateRequest()
    {
    let url:String = "https://bittrex.com/api/v1.1/public/getmarketsummaries"

    let urlRequest = URL(string: url)

    URLSession.shared.dataTask(with: urlRequest!) { (data, response, error) in
        if(error != nil){
            print(error.debugDescription)
        }
        else{
            do{
                var response = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as! [String:AnyObject]
                self.listData = response["result"] as! [[String:AnyObject]]
                DispatchQueue.main.async {
                    self.tableView.reloadData()
                }
            }catch let error as NSError{
                print(error)
            }
        }
        }.resume()
    }