Crosshairs

View model

using System.Collections.ObjectModel;
using CommunityToolkit.Mvvm.ComponentModel;
using LiveChartsCore;
using LiveChartsCore.SkiaSharpView;
using LiveChartsCore.SkiaSharpView.Painting;
using SkiaSharp;

namespace ViewModelsSamples.Axes.Crosshairs;

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

    public Axis[] XAxes { get; set; } =
    {
        new Axis
        {
            CrosshairLabelsBackground = SKColors.DarkOrange.AsLvcColor(),
            CrosshairLabelsPaint = new SolidColorPaint(SKColors.DarkRed, 1),
            CrosshairPaint = new SolidColorPaint(SKColors.DarkOrange, 1),
            Labeler = value => value.ToString("N2")
        }
    };
    public Axis[] YAxes { get; set; } =
    {
        new Axis
        {
            CrosshairLabelsBackground = SKColors.DarkOrange.AsLvcColor(),
            CrosshairLabelsPaint = new SolidColorPaint(SKColors.DarkRed, 1),
            CrosshairPaint = new SolidColorPaint(SKColors.DarkOrange, 1),
            CrosshairSnapEnabled = true // snapping is also supported
        }
    };
}

Form code behind

using System.Windows.Forms;
using LiveChartsCore.SkiaSharpView.WinForms;
using ViewModelsSamples.Axes.Crosshairs;

namespace WinFormsSample.Axes.Crosshairs;

public partial class View : UserControl
{
    private readonly CartesianChart cartesianChart;

    public View()
    {
        InitializeComponent();
        Size = new System.Drawing.Size(100, 100);

        var viewModel = new ViewModel();

        cartesianChart = new CartesianChart
        {
            Series = viewModel.Series,
            XAxes = viewModel.XAxes,
            YAxes = viewModel.YAxes,

            // out of livecharts properties...
            Location = new System.Drawing.Point(0, 50),
            Size = new System.Drawing.Size(100, 50),
            Anchor = AnchorStyles.Left | AnchorStyles.Right | AnchorStyles.Top | AnchorStyles.Bottom
        };

        Controls.Add(cartesianChart);
    }
}

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