仅在所选数据点上显示数据点？

Question

我正在使用GraphView库（http://www.android-graphview.org/legend/）构建图表。我的图表中有一个侦听器，目的是从一开始就以零个数据点开始。我想单击图表中的特定位置以显示单击位置的数据点图标。

我所拥有的例子：

Chart I have

我想要的例子：

Chart I want

这是我的代码：

class MainActivity : AppCompatActivity() {


    lateinit var series:LineGraphSeries<DataPoint>

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val series = LineGraphSeries(
            arrayOf(
                DataPoint(9.0, 9.0),
                DataPoint(10.0, 10.0),
                DataPoint(11.0, 11.0),
                DataPoint(12.0, 12.0),
                DataPoint(13.0, 13.0),
                DataPoint(14.0, 14.0)))
        graph.addSeries(series)


        var staticLabelsFormatter = StaticLabelsFormatter(graph)
        staticLabelsFormatter.setHorizontalLabels(arrayOf<String>("2018", "2019", "2020","2021","2022","2023"))
        graph.viewport.isScrollable = true
        graph.gridLabelRenderer.gridStyle = GridLabelRenderer.GridStyle.NONE
        graph.gridLabelRenderer.isVerticalLabelsVisible = false
        graph.gridLabelRenderer.labelFormatter = staticLabelsFormatter


        series.color = Color.BLACK
        series.thickness = 6
        series.isDrawBackground = true
        series.isDrawDataPoints = true
        series.isDrawDataPoints = false
        series.backgroundColor = Color.parseColor("#0D000000")


        series.setOnDataPointTapListener { series, dataPoint ->

            Toast.makeText(
                applicationContext,
                "Series1: On Data Point clicked: $dataPoint",
                Toast.LENGTH_SHORT
            ).show()
        }

    }
}