XAML-Map-Control/MapControl/Shared/MapMultiPolygon.cs

using System.Collections.Generic;
#if WPF
using System.Windows;
#elif UWP
using Windows.UI.Xaml;
#elif WINUI
using Microsoft.UI.Xaml;
#endif

namespace MapControl;

/// <summary>
/// A multi-polygon defined by a collection of collections of Locations.
/// Allows to draw filled polygons with holes.
/// 
/// A PolygonCollection (with ObservableCollection of Location elements) may be used
/// for the Polygons property if collection changes of the property itself and its
/// elements are both supposed to trigger UI updates.
/// </summary>
public partial class MapMultiPolygon : MapPolypoint
{
    public static readonly DependencyProperty PolygonsProperty =
        DependencyPropertyHelper.Register<MapMultiPolygon, IEnumerable<IEnumerable<Location>>>(nameof(Polygons), null,
            (polygon, oldValue, newValue) => polygon.DataCollectionPropertyChanged(oldValue, newValue));

    /// <summary>
    /// Gets or sets the Locations that define the multi-polygon points.
    /// </summary>
    public IEnumerable<IEnumerable<Location>> Polygons
    {
        get => (IEnumerable<IEnumerable<Location>>)GetValue(PolygonsProperty);
        set => SetValue(PolygonsProperty, value);
    }

    protected override void UpdateData()
    {
        UpdateData(Polygons);
    }
}