如何在 iOS 图表中的 X 轴上添加字符串？

在新版本中，我在创建一些图表时遇到了一些麻烦，以前的代码是：

func setChart(dataPoints: [String], values: [Double]) {
    var dataEntries: [BarChartDataEntry] = []

    for i in 0..<dataPoints.count {
        let dataEntry = BarChartDataEntry(value: values[i], xIndex: i)
        dataEntries.append(dataEntry)
    }

    let chartDataSet = BarChartDataSet(yVals: dataEntries, label: "Units Sold")
    let chartData = BarChartData(xVals: months, dataSet: chartDataSet)
    barChartView.data = chartData
}

您可以使用以下行传递值，例如月份数组：

let chartData = BarChartData(xVals: months, dataSet: chartDataSet)

新版本发布后，实现相同图表的代码是：

func setChart(dataPoints: [String], values: [Double]) {          
    var dataEntries: [BarChartDataEntry] = []

    for i in 0..<dataPoints.count {
        let dataEntry = BarChartDataEntry(x: Double(i+2), y:values[i], data: months )
        dataEntries.append(dataEntry)
    }

    let chartDataSet = BarChartDataSet(values: dataEntries, label: "Units Sold")

    let chartData = BarChartData()
    chartData.addDataSet(chartDataSet)
    barChartView.data = chartData
}

我尝试了几个小时，但找不到修改 X 轴值的方法，我希望有人可以帮助我，谢谢！

你好，最近我遇到了同样的问题，并通过以下方式解决了 -

class ViewController: UIViewController {

    var months: [String]!
    var unitsSold = [Double]()
    weak var axisFormatDelegate: IAxisValueFormatter?

    @IBOutlet var viewForChart: BarChartView!
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        axisFormatDelegate = self
        months = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
        unitsSold = [20.0, 4.0, 6.0, 3.0, 12.0, 16.0, 4.0, 18.0, 2.0, 4.0, 5.0, 4.0]

       // setChart(_ dataPoints:months,_ forY: unitsSold)
        setChart(dataEntryX: months, dataEntryY: unitsSold)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func setChart(dataEntryX forX:[String],dataEntryY forY: [Double]) {
        viewForChart.noDataText = "You need to provide data for the chart."
        var dataEntries:[BarChartDataEntry] = []
        for i in 0..<forX.count{
           // print(forX[i])
           // let dataEntry = BarChartDataEntry(x: (forX[i] as NSString).doubleValue, y: Double(unitsSold[i]))
            let dataEntry = BarChartDataEntry(x: Double(i), y: Double(forY[i]) , data: months as AnyObject?)
            print(dataEntry)
            dataEntries.append(dataEntry)
        }
        let chartDataSet = BarChartDataSet(values: dataEntries, label: "Units Sold")
        let chartData = BarChartData(dataSet: chartDataSet)
        viewForChart.data = chartData
        let xAxisValue = viewForChart.xAxis
        xAxisValue.valueFormatter = axisFormatDelegate

    }
}

最后只需添加委托的扩展名

extension ViewController: IAxisValueFormatter {

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

通过这个链接找到了这个解决方案https://medium.com/@skoli/using-realm-and-charts-with-swift-3-in-ios-10-40c42e3838c0#.minfe6kuk https://medium.com/@skoli/using-realm-and-charts-with-swift-3-in-ios-10-40c42e3838c0#.minfe6kuk