尝试在ChartDataEntry中输入日期/字符串 [英] Trying to enter Date/String in ChartDataEntry

问题描述

我正在尝试在

解决方案

如果您希望数据均匀分布(即不代表准确的时间轴)，那么答案就比较简单.

将您的 for 循环更改为

  var日期:[String] = []对于0中的i..< self.grahEntries.count {令x1 = self.grahEntries [i] .x让dateFormatter = DateFormatter()dateFormatter.dateFormat ="YYY-MM-DD HH:mm:ss"让日期= dateFormatter.date(从:x1)dates.append(日期)让dataEntry = ChartDataEntry(x:Double(i)，y:self.grahEntries [i] .y)dataEntries.append(dataEntry)} 

并更改

  mChart.xAxis.valueFormatter = DateAxisValueFormatter(日期) 

然后更改 DataAxisValueFormatter 以在构造函数中接受字符串数组并将其存储.更改

  func stringForValue(_ value:Double，axis:AxisBase?)->细绳{让我= Int(值)返回日期[i]} 

I am trying to add a Date/String as the xAxis labels in Charts (needs to have equal space in between labels)

I am doing below but the x in the constructor only expects a double.

Any idea?

for i in 0..<self.grahEntries.count {
     let x1 = self.grahEntries[i].x
     let dateFormatter = DateFormatter()
     dateFormatter.dateFormat = "YYY-MM-DD HH:mm:ss"
     let date = dateFormatter.date(from: x1)
     print(date)
     let dataEntry = ChartDataEntry(x: date, y: self.grahEntries[i].y)//HERE IS MY PROBLEM!! xAxis is only double
     dataEntries.append(dataEntry)
}

 let line1 = LineChartDataSet(values: dataEntries, label: "Units Consumed")
    line1.colors = [NSUIColor.blue]
    line1.mode = .cubicBezier
    line1.cubicIntensity = 0.2


    let gradient = getGradientFilling()
    line1.fill = Fill.fillWithLinearGradient(gradient, angle: 90.0)
    line1.drawFilledEnabled = true

    let data = LineChartData()
    data.addDataSet(line1)
    mChart.data = data
    mChart.setScaleEnabled(false)
    mChart.animate(xAxisDuration: 1.5)

    mChart.xAxis.valueFormatter = DateAxisValueFormatter()
    mChart.xAxis.granularity = 1.0


    mChart.drawGridBackgroundEnabled = false
    mChart.xAxis.drawAxisLineEnabled = false
    mChart.xAxis.drawGridLinesEnabled = false
    mChart.leftAxis.drawAxisLineEnabled = true
    mChart.leftAxis.drawGridLinesEnabled = true
    mChart.rightAxis.drawAxisLineEnabled = false
    mChart.rightAxis.drawGridLinesEnabled = false
    mChart.legend.enabled = false
    mChart.xAxis.enabled = true
    mChart.leftAxis.enabled = true
    mChart.rightAxis.enabled = false

    mChart.xAxis.labelPosition = .bottom

    mChart.xAxis.drawLabelsEnabled = true
    mChart.xAxis.drawLimitLinesBehindDataEnabled = true
    mChart.xAxis.avoidFirstLastClippingEnabled = true

UPDATE :

I did as @ces said its spreading them accurately but I still cant see labels. I updated my code above to show table

解决方案

If you want the data to be spaced evenly (i.e. not representing an accurate timeline) then the answer is simpler.

Change your for loop to

var dates: [String] = []
for i in 0..<self.grahEntries.count {
     let x1 = self.grahEntries[i].x
     let dateFormatter = DateFormatter()
     dateFormatter.dateFormat = "YYY-MM-DD HH:mm:ss"
     let date = dateFormatter.date(from: x1)
     dates.append(date)
     let dataEntry = ChartDataEntry(x: Double(i), y: self.grahEntries[i].y)
     dataEntries.append(dataEntry)
}

and change

mChart.xAxis.valueFormatter = DateAxisValueFormatter(dates)

Then change DataAxisValueFormatter to accept an array of strings in the constructor and store them. Change

func stringForValue(_ value: Double, axis: AxisBase?) -> String
{
    let i = Int(value)
    return dates[i]
}

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