如何使实时图表数据工具提示仅显示当前悬停？

Question

我有一个在 winform 中使用实时图表的饼图，并且我尝试使用文档中的代码将工具提示更改为当前悬停：

pieChart1.DataTooltip.SelectionMode = LiveCharts.TooltipSelectionMode.OnlySender;

但是我收到以下错误： 严重性代码 描述 项目文件行抑制状态

'UserControl' does not contain a definition for 'SelectionMode' and no accessible extension method 'SelectionMode' accepting a first argument of type 'UserControl' could be found (are you missing a using directive or an assembly reference?)

我不确定我错过了什么？下面的代码是我用来绘制饼图的代码。

Func<ChartPoint, string> labelPoint = chartPoint =>
            string.Format("${0:n}", chartPoint.Y, chartPoint.Participation);

        SeriesCollection series = new SeriesCollection();
        //reads in a data table and creates a pie series for each data row
        foreach (DataRow dr in dt.Rows)
        {
            PieSeries ps = new PieSeries
            {
                Title = dr["Name"].ToString(),
                Values = new ChartValues<double> {
                            double.Parse(dr["Budget Amount"].ToString())},
                DataLabels = true,
                LabelPoint = labelPoint

            };

            series.Add(ps);
        }

        pieChart1.Series = series;          
        pieChart1.LegendLocation = LegendLocation.Bottom;
        pieChart1.DataTooltip.SelectionMode = LiveCharts.TooltipSelectionMode.OnlySender;

Answer 1

DataTooltip 可以是任何 WPF 用户控件。因此，要更改 SelectionMode，您需要将其转换为DefaultTooltip.

var tooltip = (LiveCharts.DefaultTooltip) pieChart1.DataTooltip
tooltip.SelectionMode = LiveCharts.TooltipSelectionMode.OnlySender