Racing Bars

sample image

View model


using System;
using System.Linq;
using CommunityToolkit.Mvvm.ComponentModel;
using LiveChartsCore;
using LiveChartsCore.Defaults;
using LiveChartsCore.Drawing;
using LiveChartsCore.Measure;
using LiveChartsCore.SkiaSharpView;
using LiveChartsCore.SkiaSharpView.Painting;
using SkiaSharp;

namespace ViewModelsSamples.Bars.Race;

[ObservableObject]
public partial class ViewModel
{
    private readonly Random _r = new();
    private static readonly (string, double)[] s_initialData =
    {
        ("Tsunoda", 500),
        ("Sainz", 450),
        ("Riccardo", 520),
        ("Bottas", 550),
        ("Perez", 660),
        ("Verstapen", 920),
        ("Hamilton", 1000)
    };

    [ObservableProperty]
    private ISeries[] _series =
        s_initialData
            .Select(x => new RowSeries<ObservableValue>
            {
                Values = new[] { new ObservableValue(x.Item2) },
                Name = x.Item1,
                Stroke = null,
                MaxBarWidth = 25,
                DataLabelsPaint = new SolidColorPaint(new SKColor(245, 245, 245)),
                DataLabelsPosition = DataLabelsPosition.End,
                DataLabelsTranslate = new LvcPoint(-1, 0),
                DataLabelsFormatter = point => $"{point.Context.Series.Name} {point.PrimaryValue}"
            })
            .OrderByDescending(x => ((ObservableValue[])x.Values!)[0].Value)
            .ToArray();

    [ObservableProperty]
    private Axis[] _xAxes = { new Axis { SeparatorsPaint = new SolidColorPaint(new SKColor(220, 220, 220)) } };

    [ObservableProperty]
    private Axis[] _yAxes = { new Axis { IsVisible = false } };

    public void RandomIncrement()
    {
        foreach (var item in Series)
        {
            if (item.Values is null) continue;

            var i = ((ObservableValue[])item.Values)[0];
            i.Value += _r.Next(0, 100);
        }

        Series = Series.OrderByDescending(x => ((ObservableValue[])x.Values!)[0].Value).ToArray();
    }
}

HTML

@page "/Bars/Race"
@using LiveChartsCore.SkiaSharpView.Blazor
@using ViewModelsSamples.Bars.Race

<CartesianChart
	Series="ViewModel.Series"
    XAxes="ViewModel.XAxes"
    YAxes="ViewModel.YAxes"
    TooltipPosition="LiveChartsCore.Measure.TooltipPosition.Hidden">
</CartesianChart>

@code {
    protected override void OnAfterRender(bool firstRender)
    {
        base.OnAfterRender(firstRender);

        Update();
    }

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

    public async void Update()
    {
        while (true)
        {
            ViewModel.RandomIncrement();
            await Task.Delay(100);
		}
	}
}

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