iOS 图表气泡图颜色

Question

如何根据 y 值为 iOS Charts 气泡图中的单个气泡设置特定颜色？就像 iOS Charts GitHub 网站上的其中一张截图所示 here .所以所有顶层的气泡应该是相同的颜色，所有中间的都是另一个，等等......

我已经试过这样改变颜色了:

chartDataSet.colors = [UIColor.red, UIColor.orange, UIColor.green]

但这只会改变每个 x 值的颜色。

完整代码

这是我设置气泡图的完整代码:

func getDetailedAnalytics() {

    let currentTeacherDetailedAnalyticsUrl = TEACHER_DETAILED_ANALYTICS_URL + currentTeacherCourseId

    Alamofire.request(currentTeacherDetailedAnalyticsUrl).responseJSON { response in
        let result = response.result

        if let dict = result.value as? Dictionary<String, AnyObject> {

            let firstDateValue = dict["0"] as? Dictionary<String, AnyObject>
            let secondDateValue = dict["1"] as? Dictionary<String, AnyObject>
            let thirdDateValue = dict["2"] as? Dictionary<String, AnyObject>
            let fourthDateValue = dict["3"] as? Dictionary<String, AnyObject>
            let fifthDateValue = dict["4"] as? Dictionary<String, AnyObject>

            let firstDateLow = firstDateValue?["numberValuesUnder50"] as! Int
            let firstDateMiddle = firstDateValue?["numberValuesInMiddle"] as! Int
            let firstDateHigh = firstDateValue?["numberValuesOver75"] as! Int

            let secondDateLow = secondDateValue?["numberValuesUnder50"] as! Int
            let secondDateMiddle = secondDateValue?["numberValuesInMiddle"] as! Int
            let secondDateHigh = secondDateValue?["numberValuesOver75"] as! Int

            let thirdDateLow = thirdDateValue?["numberValuesUnder50"] as! Int
            let thirdDateMiddle = thirdDateValue?["numberValuesInMiddle"] as! Int
            let thirdDateHigh = thirdDateValue?["numberValuesOver75"] as! Int

            let fourthDateLow = fourthDateValue?["numberValuesUnder50"] as! Int
            let fourthDateMiddle = fourthDateValue?["numberValuesInMiddle"] as! Int
            let fourthDateHigh = fourthDateValue?["numberValuesOver75"] as! Int

            let fifthDateLow = fifthDateValue?["numberValuesUnder50"] as! Int
            let fifthDateMiddle = fifthDateValue?["numberValuesInMiddle"] as! Int
            let fifthDateHigh = fifthDateValue?["numberValuesOver75"] as! Int

            self.analyticsData = [25, 62, 88, 25, 62, 88, 25, 62, 88, 25, 62, 88, 25, 62, 88]
    self.analyticsAmountsData = [firstDateLow, firstDateMiddle, firstDateHigh, secondDateLow, secondDateMiddle, secondDateHigh, thirdDateLow, thirdDateMiddle, thirdDateHigh, fourthDateLow, fourthDateMiddle, fourthDateHigh, fifthDateLow, fifthDateMiddle, fifthDateHigh]
    self.setBubbleChart(dataPoints: self.dateBubble, values: self.analyticsData, amounts: self.analyticsAmountsData)
        }
    }
}

func setBubbleChart(dataPoints: [Int], values: [Int], amounts: [Int]) {

    var dataEntries: [BubbleChartDataEntry] = []

    for i in 0..<dataPoints.count {
        let dataEntry = BubbleChartDataEntry(x: Double(dataPoints[i]), y: Double(values[i]), size: (CGFloat(amounts[i])))
        dataEntries.append(dataEntry)
    }

    let format = NumberFormatter()
    format.generatesDecimalNumbers = false
    format.zeroSymbol = ""
    let formatter = DefaultValueFormatter(formatter: format)

    let chartDataSet = BubbleChartDataSet(values: dataEntries, label: "")
    let chartData = BubbleChartData(dataSet: chartDataSet)

    bubbleView.doubleTapToZoomEnabled = false
    bubbleView.scaleXEnabled = false
    bubbleView.scaleYEnabled = false
    bubbleView.highlightPerTapEnabled = false
    bubbleView.highlightPerDragEnabled = false

    let firstLegend = LegendEntry.init(label: "Below 50", form: .default, formSize: CGFloat.nan, formLineWidth: CGFloat.nan, formLineDashPhase: CGFloat.nan, formLineDashLengths: nil, formColor: UIColor.black)
    let secondLegend = LegendEntry.init(label: "Between 50 and 75", form: .default, formSize: CGFloat.nan, formLineWidth: CGFloat.nan, formLineDashPhase: CGFloat.nan, formLineDashLengths: nil, formColor: UIColor.black)
    let thirdLegend = LegendEntry.init(label: "Over 75", form: .default, formSize: CGFloat.nan, formLineWidth: CGFloat.nan, formLineDashPhase: CGFloat.nan, formLineDashLengths: nil, formColor: UIColor.black)

    bubbleView.chartDescription = nil
    bubbleView.legend.entries = [firstLegend, secondLegend, thirdLegend]
    bubbleView.data = chartData

    bubbleView.animate(xAxisDuration: 2.0, yAxisDuration: 2.0)

    let xAxis: XAxis = bubbleView.xAxis
    xAxis.drawAxisLineEnabled = false
    xAxis.drawGridLinesEnabled = false
    xAxis.drawLabelsEnabled = false
    xAxis.axisMinimum = 0
    xAxis.axisMaximum = 10

    let leftAxis: YAxis = bubbleView.leftAxis
    leftAxis.drawAxisLineEnabled = false
    leftAxis.drawGridLinesEnabled = false
    leftAxis.setLabelCount(2, force: true)
    leftAxis.axisMinimum = 0
    leftAxis.axisMaximum = 100

    let rightAxis: YAxis = bubbleView.rightAxis
    rightAxis.drawAxisLineEnabled = false
    rightAxis.drawGridLinesEnabled = false
    rightAxis.drawLabelsEnabled = false
}

所有值为 25 的气泡应该是相同的颜色(例如红色)，所有值为 62 的气泡应该是相同的颜色(例如橙色)，所有值为 88 的气泡应该是相同的颜色(例如绿色) ).

Answer 1

在这里看看我的回答:Different colors for bars in BarChart depend on value

但本质上，您需要编写一个自定义函数，根据值返回 UIColor。

func setColor(value: Double) -> UIColor{

if(value < 30){
    return UIColor.red
}
else if(value <= 70 && value >= 30){
    return UIColor.orange
}
else if(value > 70){
    return UIColor.green
}

else { //In case anything goes wrong
return UIColor.black
}
}

然后像这样设置颜色

chartDataSet.colors.append(setColor(dataValue))

希望这对您有所帮助!