Line Geometries

View model

using CommunityToolkit.Mvvm.ComponentModel;
using LiveChartsCore;
using LiveChartsCore.Drawing;
using LiveChartsCore.SkiaSharpView;
using LiveChartsCore.SkiaSharpView.Drawing.Geometries;

namespace ViewModelsSamples.Lines.Custom;

public partial class ViewModel : ObservableObject
{
    public ISeries[] Series { get; set; } =
    {
        new LineSeries<double>
        {
            Values = new double[] { 2, 1, 4, 2, 2, -5, -2 },
            Fill = null,
            GeometrySize = 20
        },

        // use the second type parameter to specify the geometry to draw for every point
        // there are already many predefined geometries in the
        // LiveChartsCore.SkiaSharpView.Drawing.Geometries namespace
        new LineSeries<double, RectangleGeometry>
        {
            Values = new double[] { 3, 3, -3, -2, -4, -3, -1 },
            Fill = null,
            GeometrySize = 20
        },

        // You can also use SVG paths to draw the geometry
        // LiveCharts already provides some predefined paths in the SVGPoints class.
        new LineSeries<double, SVGPathGeometry>
        {
            Values = new double[] { -2, 2, 1, 3, -1, 4, 3 },
            Fill = null,
            GeometrySvg = SVGPoints.Star,
            GeometrySize = 20
        },

        // you can declare your own gemetry and use the SkiaSharp api to draw it
        new LineSeries<double, MyGeometry>
        {
            Values = new double[] { 4, 5, 2, 4, 3, 2, 1 },
            Fill = null,
            GeometrySize = 20
        },
    };
}

MyGeometry.cs

using LiveChartsCore.SkiaSharpView.Drawing;
using LiveChartsCore.SkiaSharpView.Drawing.Geometries;
using SkiaSharp;

namespace ViewModelsSamples.Lines.Custom;

public class MyGeometry : SizedGeometry
{
    public override void OnDraw(SkiaSharpDrawingContext context, SKPaint paint)
    {
        var canvas = context.Canvas;

        canvas.DrawRect(X, Y, Width, Height, paint);
        canvas.DrawLine(X, Y, X + Width, Y + Height, paint);
        canvas.DrawLine(X + Width, Y, X, Y + Height, paint);
    }
}

HTML

@page "/Lines/Custom"
@using LiveChartsCore.SkiaSharpView.Blazor
@using ViewModelsSamples.Lines.Custom

<CartesianChart
	Series="ViewModel.Series">
</CartesianChart>

@code {
	public ViewModel ViewModel { get; set; } = new();
}

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