为 C1Chart for Silverlight 添加鼠标跟踪标记

本文主要介绍如何给 C1Chart for Silverlight 添加鼠标跟踪行为，最终会显示一条垂直红线以及红线与各个系列的交点，主要步骤：
1、添加垂直线
2、添加垂直线和系列交点的显示
3、在鼠标移动时动态改变垂直线和交点标识的位置

public partial class MainPage : UserControl
    {
        ChartPanel pnl = new ChartPanel();        

        List<Ellipse> markers;

        public MainPage()
        {
            InitializeComponent();

            AddLine();

            AddMarkers();            

            chart.View.Layers.Add(pnl);

            chart.MouseMove += new MouseEventHandler(chart_MouseMove);
        }

        void AddLine()
        {
            Point p = new Point(0, double.NaN);

            var dt = (DataTemplate)Resources["line"];
            var cpo = (ChartPanelObject)dt.LoadContent();
            cpo.DataPoint = p;
            cpo.Action = ChartPanelAction.MouseMove;
            cpo.Attach = ChartPanelAttach.DataXY;
            pnl.Children.Add(cpo);
        }

        void AddMarkers()
        {
            markers = new List<Ellipse>();

            for (int i = 0; i < chart.Data.Children.Count; i++)
            {
                Ellipse ep = new Ellipse();
                ep.Width = 50;
                ep.Height = 50;
                ep.Stroke = new SolidColorBrush(Colors.Blue);
                ep.Fill = new SolidColorBrush(Color.FromArgb(64, 0, 0, 255));
                markers.Add(ep);
                chart.View.Children.Add(ep);
            }
        }

        void SetMarkerPosition(Point pt)
        {
            double dis1;

            for (int i = 0; i < markers.Count; i++)
            {
                int p = chart.View.DataIndexFromPoint(pt, i, MeasureOption.X, out dis1);
                Point ps1 = chart.View.DataIndexToPoint(i, p);

                Canvas.SetLeft(markers[i], ps1.X - markers[i].Width / 2);
                Canvas.SetTop(markers[i], ps1.Y - markers[i].Height / 2);
            }
        }

        void chart_MouseMove(object sender, MouseEventArgs e)
        {            
            SetMarkerPosition(e.GetPosition(this));
        }
        
    }
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运行截图：