Crosshairs

Code behind

using System;
using System.Windows.Forms;
using LiveChartsCore;
using LiveChartsCore.SkiaSharpView;
using LiveChartsCore.SkiaSharpView.WinForms;
using LiveChartsCore.Measure;
using LiveChartsCore.SkiaSharpView.Painting;
using SkiaSharp;

#pragma warning disable IDE1006 // Naming Styles

namespace WinFormsSample.Axes.Crosshairs;

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

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

        // Sample data and label formatter
        var values = new double[] { 200, 558, 458, 249, 457, 339, 587 };
        static string labelFormatter(double value) => value.ToString("N2");

        var series = new ISeries[]
        {
            new LineSeries<double> { Values = values }
        };

        var crosshairColor = new SKColor(255, 0, 51);
        var crosshairBackground = new LiveChartsCore.Drawing.LvcColor(255, 0, 51);

        var xAxis = new Axis
        {
            Name = "X Axis",
            CrosshairPaint = new SolidColorPaint(crosshairColor, 2),
            CrosshairLabelsPaint = new SolidColorPaint(SKColors.White),
            CrosshairLabelsBackground = crosshairBackground,
            CrosshairPadding = new LiveChartsCore.Drawing.Padding(6)
        };

        var yAxis = new Axis
        {
            Name = "Y Axis",
            Labeler = labelFormatter,
            CrosshairPaint = new SolidColorPaint(crosshairColor, 2),
            CrosshairLabelsPaint = new SolidColorPaint(SKColors.White),
            CrosshairLabelsBackground = crosshairBackground,
            CrosshairPadding = new LiveChartsCore.Drawing.Padding(6),
            CrosshairSnapEnabled = true
        };

        cartesianChart = new CartesianChart
        {
            Series = series,
            XAxes = [xAxis],
            YAxes = [yAxis],
            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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