XAML-Map-Control/MapUiTools/Shared/MapLayerMenuItem.cs

using System.IO;
using System.Linq;
using System.Threading.Tasks;
#if WPF
using System.Windows;
using System.Windows.Markup;
#elif UWP
using Windows.UI.Xaml;
using Windows.UI.Xaml.Markup;
#elif WINUI
using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Markup;
#elif AVALONIA
using Avalonia.Metadata;
using FrameworkElement = Avalonia.Controls.Control;
#endif

namespace MapControl.UiTools;

#if WPF
[ContentProperty(nameof(MapLayer))]
#elif UWP || WINUI
[ContentProperty(Name = nameof(MapLayer))]
#endif
public partial class MapLayerMenuItem : MapMenuItem
{
#if AVALONIA
    [Content]
#endif
    public FrameworkElement MapLayer { get; set; }

    protected override bool GetIsChecked(MapBase map)
    {
        return MapLayer != null && map.Children.Contains(MapLayer);
    }

    public override Task ExecuteAsync(MapBase map)
    {
        if (MapLayer != null)
        {
            map.MapLayer = MapLayer;
        }

        return Task.CompletedTask;
    }
}

public partial class MapOverlayMenuItem : MapLayerMenuItem
{
    public string SourcePath { get; set; }

    public int InsertOrder { get; set; }

    public double OverlayOpacity { get; set; } = 1d;

    public override async Task ExecuteAsync(MapBase map)
    {
        if (MapLayer == null)
        {
            await CreateMapLayer();
        }

        if (MapLayer != null)
        {
            if (map.Children.Contains(MapLayer))
            {
                map.Children.Remove(MapLayer);
            }
            else
            {
                var insertIndex = ParentMenuItems
                    .OfType<MapOverlayMenuItem>()
                    .Where(item => item.InsertOrder <= InsertOrder && item.GetIsChecked(map))
                    .Count();

                if (map.MapLayer != null)
                {
                    insertIndex++;
                }

                map.Children.Insert(insertIndex, MapLayer);
            }
        }
    }

    protected virtual async Task CreateMapLayer()
    {
        var ext = Path.GetExtension(SourcePath).ToLower();

        if (ext == ".kmz" || ext == ".kml")
        {
            MapLayer = await GroundOverlay.CreateAsync(SourcePath);
        }
        else
        {
            MapLayer = await GeoImage.CreateAsync(SourcePath);
        }

        MapLayer.Opacity = OverlayOpacity;
    }
}