如何在WPF中查看折线图的数据点中的弹出窗口？

Question

我创建了一个折线图。

XAML

       <chartingToolkit:Chart HorizontalAlignment="Left" Margin="29,28,0,0"        Name="chart1" VerticalAlignment="Top" Height="373" Width="400"  DataContext="{Binding}" />

C＃

        System.Windows.Controls.DataVisualization.Charting.LineSeries LineSeries = new System.Windows.Controls.DataVisualization.Charting.LineSeries();
        List<KeyValuePair<string, decimal>> valueList = new List<KeyValuePair<string, decimal>>();
        DataTable dtblClass = new DataTable();
        graphSP spGraph = new graphSP();
        dtblClass = spGraph.ViewAll();

        List<KeyValuePair<String, decimal>> test = new List<KeyValuePair<string, decimal>>();
        foreach (DataRow dra in dtblClass.Rows)
        {
            valueList.Add(new KeyValuePair<string, decimal>((string)dra["customerName"], (decimal)dra["salary"]));
        }
        LineSeries.DependentValuePath = "Value";
        LineSeries.IndependentValuePath = "Key";
        LineSeries.ItemsSource = valueList;
        LineSeries.Title = "Total Salay";
        chart1.Series.Add(LineSeries);         

如何在折线图数据点而不是值中显示弹出窗口。