如何在 LiveCharts 中获取图表点的坐标

Question

我将 ObservablePoint 添加到 CartesianChart 图表。我需要在 window.

中获取该点的 x 和 y 坐标

我如何使用代码来做到这一点？

我尝试将 CartesianChart 引入 UIElement 类型以获取其中的图形元素，但我失败了。

这是我使用的代码：

Class

using System.Windows;
using LiveCharts;
using LiveCharts.Wpf;
using LiveCharts.Defaults;
using System.Windows.Media;
using System.Threading.Tasks;
using System;
using System.Threading;

namespace TestChartApp
{
    public partial class MainWindow : Window
    {
        SeriesCollection series = new SeriesCollection();

        ChartValues<ObservableValue> observableValues = new ChartValues<ObservableValue>();

        LineSeries lineSeries = new LineSeries
        {
            Stroke = Brushes.Blue,
            Fill = Brushes.Transparent,
        };

        public MainWindow()
        {
            InitializeComponent();

            observableValues.Add(new ObservableValue(0));

            lineSeries.Values = observableValues;

            series.Add(lineSeries);

            myChart.Series = series;
            myChart.DataTooltip = null;
            myChart.Hoverable = false;
        }
    }
}

XAML

<Window x:Class="TestChartApp.MainWindow"
        ...
        Title="MainWindow" Height="600" Width="1200" WindowStartupLocation="CenterScreen">
    <Grid>
        <lvc:CartesianChart x:Name="myChart" DisableAnimations="True" Width="800" HorizontalAlignment="Left">
            <lvc:CartesianChart.AxisX>
                <lvc:Axis MaxValue="100" MinValue="0" Labels="" Unit="1">
                    <lvc:Axis.Separator>
                        <lvc:Separator Step="20">
                            <lvc:Separator.Stroke>
                                <SolidColorBrush Color="Gray" />
                            </lvc:Separator.Stroke>
                        </lvc:Separator>
                    </lvc:Axis.Separator>
                </lvc:Axis>
            </lvc:CartesianChart.AxisX>
            <lvc:CartesianChart.AxisY>
                <lvc:Axis MaxValue="100" MinValue="-100" Labels="">
                    <lvc:Axis.Separator>
                        <lvc:Separator>
                            <lvc:Separator.Stroke>
                                <SolidColorBrush Color="Gray" />
                            </lvc:Separator.Stroke>
                        </lvc:Separator>
                    </lvc:Axis.Separator>
                </lvc:Axis>
            </lvc:CartesianChart.AxisY>
        </lvc:CartesianChart>
    </Grid>
</Window>

Answer 1

当您有权访问图表时，然后从映射到 SeriesColection.ChartPoints 的 SeriesCollection.Values 中找到图表兴趣点（例如，按索引映射）：

MainWindow.xaml

<Window>  
  <CartesianChart x:Name="MyChart" />
</Window>

MainWindow.xaml.cs

// Get the target series
var firstLineSeries = this.MyChart.Series[0] as LineSeries;

// Get a point from this series (in this case the first)
ChartPoint firstPointInLineSeries = firstLineSeries.ChartPointsElementAt(0);

// Convert the CahrtPoint to common WPF Point
Point convertedChartPoint = firstPointInLineSeries.AsPoint();

// Get the position of this point relative to the chart
Point chartPointPositionInChart = this.MyChart.ConvertToPixels(convertedChartPoint);

// Convert the chart point pixel coordinates 
// to the parent Window coordinates
Point chartPointPositionInWindow = this.MyChart.TransformToVisual(this).Transform(chartPointPositionInChart);

Answer 2

您是否尝试过他们文档中的解决方案？ Link

     private void ChartOnDataClick(object sender, ChartPoint p)
        {
            var asPixels = cartesianChart1.Base.ConvertToPixels(p.AsPoint());
            Console.WriteLine("[EVENT] You clicked (" + p.X + ", " + p.Y + ") in pixels (" +
                            asPixels.X + ", " + asPixels.Y + ")");
        }

如何在 LiveCharts 中获取图表点的坐标

How to get the coordinates of a chart point in LiveCharts

c#

wpf

livecharts