World Heat Map
The [ObservableObject], [ObservableProperty] and [ICommand] attributes come from the
CommunityToolkit.Mvvm package, you can read more about it
here.
This web site wraps every sample using a UserControl instance, but LiveCharts controls can be used inside any container.
View model
using System;
using System.Linq;
using System.Threading.Tasks;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using LiveChartsCore.Geo;
using LiveChartsCore.SkiaSharpView;
using LiveChartsCore.SkiaSharpView.Drawing.Geometries;
namespace ViewModelsSamples.Maps.World;
public partial class ViewModel
{
private bool _isBrazilInChart = true;
private readonly IWeigthedMapLand _brazil;
private readonly Random _r = new();
public ViewModel()
{
// every country has a unique identifier
// check the "shortName" property in the following
// json file to assign a value to a country in the heat map
// https://github.com/beto-rodriguez/LiveCharts2/blob/master/docs/_assets/word-map-index.json
var lands = new HeatLand[]
{
new() { Name = "bra", Value = 13 },
new() { Name = "mex", Value = 10 },
new() { Name = "usa", Value = 15 },
new() { Name = "can", Value = 8 },
new() { Name = "ind", Value = 12 },
new() { Name = "deu", Value = 13 },
new() { Name= "jpn", Value = 15 },
new() { Name = "chn", Value = 14 },
new() { Name = "rus", Value = 11 },
new() { Name = "fra", Value = 8 },
new() { Name = "esp", Value = 7 },
new() { Name = "kor", Value = 10 },
new() { Name = "zaf", Value = 12 },
new() { Name = "are", Value = 13 }
};
Series = new HeatLandSeries[] { new HeatLandSeries { Lands = lands } };
_brazil = lands.First(x => x.Name == "bra");
DoRandomChanges();
}
public HeatLandSeries[] Series { get; set; }
[RelayCommand]
public void ToggleBrazil()
{
var lands = Series[0].Lands;
if (lands is null) return;
if (_isBrazilInChart)
{
Series[0].Lands = lands.Where(x => x != _brazil).ToArray();
_isBrazilInChart = false;
return;
}
Series[0].Lands = lands.Concat(new[] { _brazil }).ToArray();
_isBrazilInChart = true;
}
private async void DoRandomChanges()
{
await Task.Delay(1000);
while (true)
{
foreach (var shape in Series[0].Lands ?? Enumerable.Empty<IWeigthedMapLand>())
{
shape.Value = _r.Next(0, 20);
}
await Task.Delay(500);
}
}
}
XAML
<UserControl x:Class="WPFSample.Maps.World.View"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:lvc="clr-namespace:LiveChartsCore.SkiaSharpView.WPF;assembly=LiveChartsCore.SkiaSharpView.WPF"
xmlns:vms="clr-namespace:ViewModelsSamples.Maps.World;assembly=ViewModelsSamples">
<UserControl.DataContext>
<vms:ViewModel/>
</UserControl.DataContext>
<lvc:GeoMap Series="{Binding Series}" MapProjection="Mercator"/>
</UserControl>
