chore: Addressing Shadows PR remaining comments (#696)

# Conflicts:
#	src/Uno.Toolkit.Skia.WinUI/Controls/Shadows/ShadowContainer.cs

samples/Uno.Toolkit.Samples/Uno.Toolkit.Samples.Shared/Converters/HexToColorConverter.cs

@@ -4,8 +4,10 @@
 
 #if IS_WINUI
 using Microsoft.UI.Xaml.Data;
+using Microsoft.UI.Xaml.Markup;
 #else
 using Windows.UI.Xaml.Data;
+using Windows.UI.Xaml.Markup;
 #endif
 
 namespace Uno.Toolkit.Samples.Converters
@@ -24,13 +26,7 @@ public object ConvertBack(object value, Type targetType, object parameter, strin
 				return value;
 			}
 
-			hex = hex.Replace("#", string.Empty);
-			byte a = (byte)(System.Convert.ToUInt32(hex.Substring(0, 2), 16));
-			byte r = (byte)(System.Convert.ToUInt32(hex.Substring(2, 2), 16));
-			byte g = (byte)(System.Convert.ToUInt32(hex.Substring(4, 2), 16));
-			byte b = (byte)(System.Convert.ToUInt32(hex.Substring(6, 2), 16));
-
-			return Color.FromArgb(a, r, g, b);
+			return XamlBindingHelper.ConvertValue(typeof(Color), hex);
 		}
 	}
 }

src/Uno.Toolkit.Skia.WinUI/Controls/Shadows/ShadowCollection.cs

@@ -1,4 +1,5 @@
 using System.Collections.ObjectModel;
+using System.Globalization;
 using System.Linq;
 
 namespace Uno.Toolkit.UI;
@@ -8,6 +9,7 @@ public class ShadowCollection : ObservableCollection<Shadow>
 	public bool HasInnerShadow() => this.Any(s => s.IsInner);
 
 	public string ToKey(double width, double height, Windows.UI.Color? contentBackground)
-		=> $"w{width},h{height}" + (contentBackground.HasValue ? $",cb{contentBackground.Value}:" : ":") +
+		=> string.Create(CultureInfo.InvariantCulture, $"w{width},h{height}") +
+		(contentBackground.HasValue ? $",cb{contentBackground.Value}:" : ":") +
 		string.Join("/", this.Select(x => x.ToKey()));
 }

src/Uno.Toolkit.Skia.WinUI/Controls/Shadows/ShadowContainer.Properties.cs

@@ -27,7 +27,7 @@ public partial class ShadowContainer : ContentControl
 			nameof(Shadows),
 			typeof(ShadowCollection),
 			typeof(ShadowContainer),
-			new(new ShadowCollection(), OnShadowsChanged));
+			new(null, OnShadowsChanged));
 
 	/// <summary>
 	/// The collection of shadows that will be displayed under your control.

src/Uno.Toolkit.Skia.WinUI/Controls/Shadows/ShadowContainer.cs

@@ -49,6 +49,8 @@ public ShadowContainer()
 #if HAS_UNO_WINUI && !NET6_0_OR_GREATER
 		throw new NotSupportedException("ShadowContainer doesn't support Xamarin + WinUI considering moving to .NET6 or greater.");
 #else
+		Shadows = new();
+
 		DefaultStyleKey = typeof(ShadowContainer);
 
 		_cornerRadius = new CornerRadius(0);