如何遍歷Swift數組並在iOS圖表中使用數據？

Question

我有一個條形圖，我試圖通過從數組中提取的數據來填充該條形圖。

我試圖遍歷此數組以填充我的圖表。

請注意：在下面的示例中，有3個winningStreakDM變量被硬編碼用於測試目的，但是在“現實生活”中，每個API調用的數量可能不同，這取決於該聯盟中有多少“用戶”。

這就是為什么我需要遍歷數組並構造適合的數據的原因。

    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
    ]

我的問題是我不知道如何遍歷初始數組來構造數據以使其與上述代碼一起使用。

這是我的完整腳本：

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：

這些是我目前收到的錯誤：

經過一些試驗並注釋掉了包含第一個錯誤的行，我到了這個階段，該階段可以正確顯示帶有值的圖形，但是沒有xAxis包含每個玩家的用戶名。

Answer 1

您可以通過這種方式創建BarChartDataEntry數組。

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

編輯：您只需要更改setWinStreakChart函數，因為現在您正在使用動態數據而不是靜態數據。

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
}

現在在for循環之后調用此函數，在該循環中我們將創建BarChartDataEntry數組。

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