Dashed Lines

View Model

using CommunityToolkit.Mvvm.ComponentModel;
using LiveChartsCore;
using LiveChartsCore.SkiaSharpView;
using LiveChartsCore.SkiaSharpView.Painting;
using LiveChartsCore.SkiaSharpView.Painting.Effects;
using SkiaSharp;

namespace ViewModelsSamples.Design.StrokeDashArray;

public partial class ViewModel : ObservableObject
{
    public ViewModel()
    {
        // The LiveChartsCore.SkiaSharpView.Painting.EffectsPathEffect abstract class is a wrapper for
        // the SkiaSharp.SKPathEffect object, in this case we will use the DashEffect class
        // to create a dash line as the stroke of our line series

        // notice the stroke thickness affects the stroke dash array
        // if you want to learn more about stroke dash arrays please see:
        // https://docs.microsoft.com/en-us/xamarin/xamarin-forms/user-interface/graphics/skiasharp/curves/effects#dots-and-dashes

        var strokeThickness = 10;
        var strokeDashArray = new float[] { 3 * strokeThickness, 2 * strokeThickness };
        var effect = new DashEffect(strokeDashArray);

        Series = new ISeries[]
        {
            new LineSeries<int>
            {
                Values = new [] { 4, 2, 8, 5, 3 },
                LineSmoothness = 1,
                GeometrySize = 22,
                Stroke = new SolidColorPaint
                {
                    Color = SKColors.CornflowerBlue,
                    StrokeCap = SKStrokeCap.Round,
                    StrokeThickness = strokeThickness,
                    PathEffect = effect
                },
                Fill = null
            }
        };
    }

    public ISeries[] Series { get; set; }
}

XAML

<UserControl
    x:Class="UnoWinUISample.Design.StrokeDashArray.View"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:lvc="using:LiveChartsCore.SkiaSharpView.WinUI"
    xmlns:vms="using:ViewModelsSamples.Design.StrokeDashArray"
    mc:Ignorable="d">

    <UserControl.DataContext>
        <vms:ViewModel/>
    </UserControl.DataContext>
    <Grid>
        <lvc:CartesianChart Series="{Binding Series}" LegendPosition="Right"></lvc:CartesianChart>
    </Grid>
    
</UserControl>