添加项目文件。

Live-Charts-master/Examples/Wpf/CartesianChart/UIElements/UiElementsViewModel.cs

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+using System;
+using System.Linq;
+using System.Windows;
+using LiveCharts;
+using LiveCharts.Defaults;
+using LiveCharts.Helpers;
+using LiveCharts.Wpf;
+
+namespace Wpf.CartesianChart.UIElements
+{
+    public class UiElementsViewModel
+    {
+        private DateTimePoint _selectedPoint;
+
+        public UiElementsViewModel()
+        {
+            Values = DataProvider.Points.AsChartValues();
+            Formatter = x => new DateTime((long) x).ToString("dd MMM");
+            Step = TimeSpan.FromDays(1).Ticks * 2;
+
+            //lets get some random points to add an even in the chart.
+            var e1 = Values.Skip(15).Take(1).First();
+            var e2 = Values.Skip(35).Take(1).First();
+
+            SelectedVisualElement = new VisualElement
+            {
+                HorizontalAlignment = HorizontalAlignment.Center,
+                VerticalAlignment = VerticalAlignment.Bottom,
+                UIElement = new SelectedItemControl()
+            };
+
+            Visuals = new VisualElementsCollection
+            {
+                new VisualElement
+                {
+                    X = e1.DateTime.Ticks,
+                    Y = e1.Value,
+                    HorizontalAlignment = HorizontalAlignment.Center,
+                    VerticalAlignment = VerticalAlignment.Top,
+                    UIElement = new EventAControl()
+                },
+                new VisualElement
+                {
+                    X = e2.DateTime.Ticks,
+                    Y = e2.Value,
+                    HorizontalAlignment = HorizontalAlignment.Center,
+                    VerticalAlignment = VerticalAlignment.Top,
+                    UIElement = new EventBControl()
+                },
+                SelectedVisualElement
+            };
+        }
+
+        public ChartValues<DateTimePoint> Values { get; set; }
+        public VisualElementsCollection Visuals { get; set; }
+        public VisualElement EventA { get; set; }
+        public VisualElement EventB { get; set; }
+        public VisualElement SelectedVisualElement { get; set; }
+        public Func<double, string> Formatter { get; set; }
+        public double Step { get; set; }
+        public DateTimePoint SelectedPoint
+        {
+            get { return _selectedPoint; }
+            set
+            {
+                _selectedPoint = value;
+                UpdateSelectedVisual();
+            }
+        }
+
+        private void UpdateSelectedVisual()
+        {
+            SelectedVisualElement.X = SelectedPoint.DateTime.Ticks;
+            SelectedVisualElement.Y = SelectedPoint.Value;
+        }
+    }
+}