iOS 使用多个数据集的图表 (MPAndroidChart) 始终显示“没有可用的图表数据”

Question

None of the solutions, in the multiple SO questions, for "No chart data available" is able to remove/modify the message:

MPAndroidchart No chart Data available

How to change the No Data message using iOS Charts?

collection view presentation of graph: "no chart data available" for Charts cocoapods

The chart displays the data correctly but also displays the message "No chart data available". It really just seems like a bug for the chart to have data but show this message.

The only difference between the other SO questions and my problem is that I'm setting the data with dataSets instead of dataSet viz. LineChartData(dataSets: data_sets) . Seeing this difference I tried creating the LineChart view with a dummy LineChartData initialized with dataSet , before running updateChartData() , but this didn't help either.

I don't see a way to initialize the LineChartView with the data, the closest I've seen to potentially doing this is shown on this site

@IBOutlet weak var chartview_box: UIView!
var chartview: LineChartView 

override func viewDidLoad() {
    chartview = LineChartView()
    chartview.noDataText = "test"
    chartview.noDataTextColor = UIColor(hue: 0, saturation: 0, brightness: 0, alpha: 0)
    setChartOptions()
    updateChartData()
}

func updateChartData() {
    var data_sets: Array<LineChartDataSet> = []
    for frame in frames! {
        ... code setting x and y
        let entry = ChartDataEntry(x: x, y: y)
        let data_set = LineChartDataSet(entries: [entry])
        data_sets.append(data_set)
    }
    let data = LineChartData(dataSets: data_sets)
    chartview.data = data
}

Answer 1

This ended up being an issue with accidentally leaving a parent container as LineChartView when it should be UIView, so the parent view "behind" the chart was also a chart and displaying the message.