ios - iOS 图表未显示所有 xAxis 值

Question

我正在用Swift 4.2编写iOS 应用程序 我正在使用Charts库来显示Horizo​​ntal Bar Chart。我需要设置它的 xAxis 值。仅显示最后一个值。

问题截图：

代码片段：

@IBOutlet var chartView: HorizontalBarChartView!

override func viewDidLoad() {
        super.viewDidLoad()

        let xAxis = chartView.xAxis
        xAxis.labelPosition = .bottom
        xAxis.labelFont = .systemFont(ofSize: 10)
        xAxis.drawAxisLineEnabled = false
        xAxis.drawGridLinesEnabled = false
        xAxis.granularity = 1
        xAxis.enabled=true

    xAxis.setLabelCount(3, force: false) //Not working as per expectations
   xAxis.valueFormatter=IndexAxisValueFormatter(values: ["A","B","C"])  //Not working as per expectations




        self.setDataCount(3,values:[142000,122400,100110])
        chartView.animate(yAxisDuration: 2.5)
    }


    func setDataCount(_ count: Int, values:[Double]) {
        let barWidth = 2.0
        let spaceForBar = 4.0
        var n=0
        let yVals = (0..<count).map { (i) -> BarChartDataEntry in

            let val = values[n]
            n+=1

            return BarChartDataEntry(x: Double(i)*spaceForBar, y: val)

        }

        let set1 = BarChartDataSet(entries: yVals, label: "DataSet")
        set1.drawIconsEnabled = false

        let data = BarChartData(dataSet: set1)
        data.setValueFont(UIFont(name:"HelveticaNeue-Light", size:10)!)
        data.barWidth = barWidth

        chartView.data = data

        //let xAxis = chartView.xAxis
        //xAxis.setLabelCount(3, force: false)
        //xAxis.valueFormatter=IndexAxisValueFormatter(values: ["A","B","C"])
    }

我试图找到解决方案：

xAxis.valueFormatter=IndexAxisValueFormatter(values: ["A","B","C"]) 

但这些都不起作用。

标签： iosswiftios-charts

Answer 1

发生这种情况是因为默认功能IndexAxisValueFormatter

IAxisValueFormatter您必须像这样编写自己的自定义代码

final class CustomFormatter: IAxisValueFormatter {

    var labels: [String] = []

    func stringForValue(_ value: Double, axis: AxisBase?) -> String {

        let count = self.labels.count

        guard let axis = axis, count > 0 else {
            return ""
        }

        let factor = axis.axisMaximum / Double(count)

        let index = Int((value / factor).rounded())

        if index >= 0 && index < count {
            return self.labels[index]
        }

        return ""
    }
}

然后像这样使用它

 let customFormater = CustomFormater()
 customFormater.labels = ["A","B","C"]

 chartView.xAxis.valueFormatter = customFormater

确保数据和标签的大小/数量相同，否则不会给你想要的结果。