如何设置swift图表（折线图）中x轴线的绘制位置？

Question

我在 iOS 应用程序中使用 swift 的图表。我目前将其设置在仅显示 x 轴线的位置，我想设置绘制 x 轴线的 y 值。为了说明这一点，我正在制作一张股票图表，并希望将 x 轴线设置为股票的第一个值（开盘价）。这是我当前的折线图视图。

编辑：现在线条总是绘制到视图的顶部。

let chartView: LineChartView = {
    let view = LineChartView()
    view.noDataText = ""
    view.legend.enabled = false
    view.legend.textColor = .clear

    //X Axis
    view.xAxis.wordWrapEnabled = true
    view.xAxis.drawLabelsEnabled = false
    view.xAxis.drawAxisLineEnabled = true
    view.xAxis.axisLineColor = .white
    view.xAxis.axisLineDashLengths = [2]
    view.xAxis.drawGridLinesEnabled = false

    //Y Axis
    view.rightAxis.enabled = false
    view.leftAxis.enabled = false
    view.leftAxis.gridColor = .clear
    view.rightAxis.gridColor = .clear
    view.leftAxis.drawLabelsEnabled = false

    view.leftAxis.axisMinimum = points[0] //HERE

    return view
}()

Answer 1

我认为使用额外的数据集是在图表上绘制水平线的最简单方法。

    var xMinValue: Double = 0 // use your own value
    var xMaxValue: Double = 12 // use your own value

    var yFirstValue: Double = 9  // set your open price

    let horizontalLineDataEntries: [ChartDataEntry] = [
        ChartDataEntry(x: xMinValue, y: yFirstValue),
        ChartDataEntry(x: xMaxValue, y: yFirstValue)
    ]

    let horizontalLineSataSet = LineChartDataSet(values: horizontalLineDataEntries, label: nil)
    horizontalLineSataSet.setColor(.blue)
    horizontalLineSataSet.lineWidth = 2
    horizontalLineSataSet.drawCirclesEnabled = false
    horizontalLineSataSet.drawValuesEnabled = false

    chartData.addDataSet(horizontalLineSataSet)

    chartView.data = chartData

如何设置swift图表（折线图）中x轴线的绘制位置？

How to set where the x-axis line is drawn in swift charts (line chart)?

charts

swift

ios-charts