在x轴上带有日期和时间的烛台图

时间:2019-01-02 12:48:38

标签: swift datetime charts axis-labels candlestick-chart

我正在尝试使用Charts Framework创建烛台图,并使用Codable作为JSON,通过myclass可以显示为:

struct ChartDataPair: Codable {
var DateTime: String  = ""
var Open: Double = 0.0
var High: Double = 0.0
var Low: Double = 0.0
var Close: Double = 0.0
}

哪个会创建一个chartDataPairs数组,如下所示:

struct ChartData: Codable {
var chartDataPairs: [ChartDataPair]
}

我要获取的值如下所示:

 {"chartDataPairs":
               [{
              "DateTime": "2018/10/1 10:00:01",
              "Open": 50.05,
              "High": 50.05,
              "Low": 49.00,
              "Close":49.00
              },
              {
              "DateTime": "2018/10/1 10:05:02",
              "Open": 51.05,
              "High": 54.06,
              "Low": 40.00,
              "Close":45.06
              },
              {
              "DateTime": "2018/10/1 10:10:02",
              "Open": 50.05,
              "High": 64.06,
              "Low": 40.00,
              "Close":58.06
              }]
}

数据只是一个样本,所以只写了3个值。现在,我只需要获取时间并将DateTime字符串转换为Double即可在图表的x轴上进行绘制。对于我正在使用:

var dataEntries: [ChartDataEntry] = []
guard let financialData = dataChart.self else {
return
}
for chartData in financialData{
let open = chartData.Open
let close = chartData.Close
let high = chartData.High
let low = chartData.Low
let datetime = chartData.DateTime
let formatter = DateFormatter()
formatter.dateFormat = "YYYY/MM/dd HH:mm:ss"
let yourDate = formatter.date(from: datetime)
formatter.dateFormat = "HH:mm"
let myStringafd = formatter.string(from: yourDate!)

let time = myStringafd
let components = time.characters.split { $0 == ":" } .map { (x) -> Int in return Int(String(x))! }

let hours = components[0]
let minutes = components[1]

let double1 = Double("\(hours).\(minutes)")

let dataEntry = CandleChartDataEntry(x: double1! , shadowH: high, shadowL: low, open: open, close: close)
dataEntries.append(dataEntry)
}
    let chartDataSet = CandleChartDataSet(values: dataEntries, label: "")

chartDataSet.axisDependency = .left
chartDataSet.drawIconsEnabled = false
chartDataSet.shadowColor = .darkGray
chartDataSet.shadowWidth = 0.7
chartDataSet.decreasingColor = .red
chartDataSet.decreasingFilled = true   // fill up the decreasing field color
chartDataSet.increasingColor = UIColor(red: 122/255, green: 242/255, blue: 84/255, alpha: 1)
chartDataSet.increasingFilled = true  // fill up the increasing field color
chartDataSet.neutralColor = .blue
chartDataSet.barSpace = 1.0
chartDataSet.drawValuesEnabled = false

let chartData = CandleChartData(dataSet: chartDataSet)
candlestickView.data = chartData

我知道将时间转换为double ins的正确性是不正确的,在这里我需要一些有关将datetime转换为double值的帮助。

第二个问题是烛台的横条宽度,我无法减小烛台的宽度。

我想用诸如HH:MM之类的时间值以某些间隔(例如15分钟,50分钟,4小时等)填充x轴。

在下面的给定链接中,我遵循的几个问题和建议: iOS-Charts Library: x-axis labels without backing data not showing

关于此问题:candlestickView.xAxisRenderer = XAxisWeekRenderer()

不起作用。它呼吁使用视口处理器,x轴和进行变换。

尽管我可以从自定义IAxisValueFormatter获得自定义标签。 x轴上两个值之间的间隔不是我想要的15分钟或50分钟或4小时等的间隔。

ios Charts 3.0 - Align x labels (dates) with plots

在上述链接上,我无法获得minTimeInterval and referenceTimeInterval

基本上,我要做的是绘制从X轴上的JSON获取的字符串中的小时和分钟,并在创建自定义X轴的同时在X轴的值之间创建自定义间隔标签。

我的图表当前显示为: Candlestick Chart

1 个答案:

答案 0 :(得分:0)

我要显示相同的内容,所以我用这种方式显示数据

        let xAxis = chartView.xAxis
        var dataPoints = [String]()
        for i in 0 ..< arrData.count
        {


            let timeStampFrom = arrData[i].time
            dataPoints.append(self.stringFromTimestamp(timeStampFrom, strDateFormat: "h a"))

        }
        xAxis.valueFormatter = IndexAxisValueFormatter(values:dataPoints)
        xAxis.setLabelCount(5, force: false)

一些需要的功能

func stringFromTimestamp(_ timeInterval : Double ,strDateFormat : String)->String 
    {
        let dateFormatter = DateFormatter()
        self.setDateFormat(dateFormatter,dateFormat: strDateFormat)
        let date = Date(timeIntervalSince1970: TimeInterval(timeInterval))
        return dateFormatter.string(from: date)
    }

这是输出

enter image description here