Crosshairs

This sample uses C# 12 features, it also uses features from the CommunityToolkit.Mvvm package, you can learn more about it here.

sample image

View model

using SkiaSharp;
using LiveChartsCore;
using LiveChartsCore.SkiaSharpView;
using LiveChartsCore.SkiaSharpView.Painting;
using LiveChartsCore.Kernel.Sketches;

namespace ViewModelsSamples.Axes.Crosshairs;

public class ViewModel
{
    public ISeries[] Series { get; set; } = [
        new LineSeries<double> { Values = [200, 558, 458, 249, 457, 339, 587] },
        new LineSeries<double> { Values = [210, 400, 300, 350, 219, 323, 618] },
    ];

    public ICartesianAxis[] XAxes { get; set; } = [
        new Axis
        {
            CrosshairLabelsBackground = SKColors.DarkOrange.AsLvcColor(),
            CrosshairLabelsPaint = new SolidColorPaint(SKColors.DarkRed),
            CrosshairPaint = new SolidColorPaint(SKColors.DarkOrange, 1),
            Labeler = value => value.ToString("N2")
        }
    ];

    public ICartesianAxis[] YAxes { get; set; } = [
        new Axis
        {
            CrosshairLabelsBackground = SKColors.DarkOrange.AsLvcColor(),
            CrosshairLabelsPaint = new SolidColorPaint(SKColors.DarkRed),
            CrosshairPaint = new SolidColorPaint(SKColors.DarkOrange, 1),
            CrosshairSnapEnabled = true // snapping is also supported
        }
    ];
}

XAML

<UserControl x:Class="AvaloniaSample.Axes.Crosshairs.View"
             xmlns="https://github.com/avaloniaui"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:lvc="using:LiveChartsCore.SkiaSharpView.Avalonia"
             xmlns:vms="using:ViewModelsSamples.Axes.Crosshairs">
  <UserControl.DataContext>
    <vms:ViewModel/>
  </UserControl.DataContext>
    <Grid>
        <lvc:CartesianChart
            Series="{Binding Series}"
            XAxes="{Binding XAxes}"
            YAxes="{Binding YAxes}">
        </lvc:CartesianChart>
    </Grid>
</UserControl>

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