如何遍历 Swift 数组并使用 iOS 图表中的数据？

Question

我有一个条形图，我试图通过从数组中提取的数据来填充它。

我正在尝试遍历此数组以填充我的图表。

请注意： 在下面的示例中，有 3 个 winningStreakDM 变量被硬编码用于测试目的，但在 'real life' 中，每个变量的数量可能不同 API调用，因为这取决于该联盟中有多少 'users'。

这就是为什么我需要遍历数组并构建适合的数据。

    let winningStreakDM1 : [String : Any] = [
        "id" : 2,
        "user_name" : "Dicky",
        "winning_streak" : 5
    ]

    let winningStreakDM2 : [String : Any] = [
        "id" : 6,
        "user_name" : "G",
        "winning_streak" : 2
    ]

    let winningStreakDM3 : [String : Any] = [
        "id" : 5,
        "user_name" : "Sultan",
        "winning_streak" : 0
    ]

我的问题是我不知道如何遍历初始数组来构建我的数据以使其与上述代码一起工作。

这是我的完整脚本：

import UIKit
import Charts

class CommunityLeagueStatsVC: UIViewController {


// GRAPHS *********

@IBOutlet weak var chartView: BarChartView!
var values = [BarChartDataEntry]()

// ****************
//********CHART VARIABLES**************//

//WINS LOSSES DRAWS
var winStreak: Double = 0.0

@IBOutlet weak var leagueStatsScrollView: UIScrollView!

var noDefeats: Bool?
var noWins: Bool?
var biggestWin: String?
var biggestWinTeams: String?

var passedCommunityName: String?
@IBOutlet weak var communityName: UILabel!

var playerId2: String?
var communityId2: String?
var eMail2: String?

override func viewDidLoad() {
    super.viewDidLoad()


    let winningStreak =  ["Wins"]
    let gamesWon = [winStreak]
    setWinStreakChart(dataPoints: winningStreak, values: gamesWon)

    let defaults = UserDefaults.standard
    let Email = defaults.string(forKey: "userEmail")
    let playerId = defaults.string(forKey: "playerId")
    let commsId = defaults.string(forKey: "communityId")

    self.playerId2 = playerId
    self.communityId2 = commsId
    self.eMail2 = Email


}

 func setWinStreakChart(dataPoints: [String], values: [BarChartDataEntry]){

    xAxis.valueFormatter = WinningStreakFormatter(chartView: self.chartView)
    let barChartDataSet = BarChartDataSet(values: values, label: "Winning Streak")
    barChartDataSet.colors = ChartColorTemplates.material()

    let barChartData = BarChartData(dataSet: barChartDataSet)
    barChartData.setValueFont(UIFont.systemFont(ofSize: 12.0))
    self.chartView.data = barChartData
}


override func viewDidAppear(_ animated: Bool) {

    let myUrl = URL(string: "http://www.xxx.uk/xxx/getLeagueStats.php")
    var request = URLRequest(url:myUrl!)
    request.httpMethod = "POST"

    let postString = "player_id=\(self.playerId2!)&community_id=\(communityId2!)";

    request.httpBody = postString.data(using: String.Encoding.utf8);
    let task = URLSession.shared.dataTask(with: request) { (data: Data?, response: URLResponse?, error: Error?) in
        DispatchQueue.main.async
            {
                do{

                    let json = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as? [String:AnyObject]
                    print (json!)

                       if let dict = json?["leagueStats"] as? [String:AnyObject] {

                          //WINNING STREAK

                        var values = [BarChartDataEntry]()

                        if let dataWinStreak = dict["winningStreak"] as? [[String : Any]] {
                            print ("test one")
                            for (index,item) in dataWinStreak.enumerated() {
                                if let yValue = item["winning_streak"] as? Int, let userName = item["user_name"] as? String {
                                    print ("test two")
                                    let barChartDataEntry = BarChartDataEntry(x: Double(index), y: Double(yValue), data: userName as AnyObject?)
                                    values.append(barChartDataEntry)

                                }
                            }

                            self.setWinStreakChart(dataPoints: ["wins"], values: values)
                        }
        catch{
            print(error)
                }
        }
        }
    task.resume()

}
}

更新：

这些是我目前收到的错误：

经过一些尝试并注释掉包含第一个错误的行，我已经到了这个阶段，它正确地显示了一个带有值的图表，但没有包含每个玩家的用户名的 xAxis。

Answer 1

您可以通过这种方式创建 BarChartDataEntry 数组。

var values = [BarChartDataEntry]()

if let dataWinStreak = dict["winningStreak"] as? [[String : Any]] {
    for (index,item) in dataWinStreak.enumerated() {
        if let yValue = item["winning_streak"] as? Int, let userName = item["user_name"] as? String {
            let barChartDataEntry = BarChartDataEntry(x: index, y: yValue, data: userName)
            values.append(barChartDataEntry)
        }
    }
}
//Now use values array

编辑： 您只需要更改 setWinStreakChart 函数，因为现在您使用的是动态数据，而不是静态数据。

func setWinStreakChart(dataPoints: [String], values: [BarChartDataEntry]){

    let  xAxis : XAxis = self.chartView.xAxis;
    xAxis.labelFont = UIFont(name: "HelveticaNeue-Light", size: 10.0)!
    xAxis.labelTextColor = UIColor.black
    xAxis.drawAxisLineEnabled = false
    xAxis.drawGridLinesEnabled = true
    xAxis.granularity = 1;
    xAxis.labelPosition = .bottom

    xAxis.valueFormatter = WinningStreakFormatter(chartView: self.chartView)
    let barChartDataSet = BarChartDataSet(values: values, label: "Winning Streak")
    barChartDataSet.colors = ChartColorTemplates.material()

    let barChartData = BarChartData(dataSet: barChartDataSet)
    barChartData.setValueFont(UIFont.systemFont(ofSize: 12.0))
    self.chartView.data = barChartData
}

现在在创建 BarChartDataEntry 数组的 for 循环之后调用此函数。

self.setWinStreakChart(dataPoints: ["wins"], values: values)

如何遍历 Swift 数组并使用 iOS 图表中的数据？

How to iterate through Swift array and use data in iOS Chart?

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ios-charts