[iOS] Fixed CollectionView Scroll Jitter for TextType HTML Labels

src/Controls/src/Core/Platform/iOS/Extensions/LabelExtensions.cs

@@ -1,6 +1,7 @@
 #nullable disable
 using Microsoft.Maui;
 using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Handlers.Items2;
 using Microsoft.Maui.Controls.Internals;
 using ObjCRuntime;
 using UIKit;
@@ -16,22 +17,37 @@ public static void UpdateText(this UILabel platformLabel, Label label)
 			switch (label.TextType)
 			{
 				case TextType.Html:
-					// NOTE: Setting HTML text this will crash with some sort of consistency error.
+					// NOTE: Setting HTML text like this will crash with some sort of consistency error.
+					// when inside a CV1 (CollectionView/CarouselView handler v1) layout pass.
 					// https://github.com/dotnet/maui/issues/25946
-					// Here we have to dispatch back the the main queue to avoid the crash.
-					// This is observed with CarouselView 1 but not with 2, so hopefully this
-					// will be just disappear once we switch.
-					CoreFoundation.DispatchQueue.MainQueue.DispatchAsync(() =>
+					// CV2 (the default handler in .NET 10) does NOT have this crash.
+					if (IsPlatformLabelInsideCV2Cell(platformLabel))
 					{
+						// Synchronous: safe in CV2, avoids the two-pass jitter.
+						// No InvalidateMeasure needed — text is already correct when measured.
 						platformLabel.UpdateTextHtml(text);
 
-						if (label.Handler is LabelHandler labelHandler)
-							Label.MapFormatting(labelHandler, label);
+						if (label.Handler is LabelHandler labelHandlerSync)
+						{
+							Label.MapFormatting(labelHandlerSync, label);
+						}
+					}
+					else
+					{
+						CoreFoundation.DispatchQueue.MainQueue.DispatchAsync(() =>
+						{
+							platformLabel.UpdateTextHtml(text);
+
+							if (label.Handler is LabelHandler labelHandler)
+							{
+								Label.MapFormatting(labelHandler, label);
+							}
 
-						// NOTE: Because we are updating text outside the normal layout
-						// pass, we need to invalidate the measure for the next pass.
-						label.InvalidateMeasure();
-					});
+							// NOTE: Because we are updating text outside the normal layout
+							// pass, we need to invalidate the measure for the next pass.
+							label.InvalidateMeasure();
+						});
+					}
 					break;
 
 				default:
@@ -49,5 +65,20 @@ public static void UpdateText(this UILabel platformLabel, Label label)
 					break;
 			}
 		}
+
+		// Walks the native UIKit superview chain to determine if this UILabel lives inside a CV2 cell.
+		static bool IsPlatformLabelInsideCV2Cell(UILabel platformLabel)
+		{
+			var superview = platformLabel.Superview;
+			while (superview is not null)
+			{
+				if (superview is ItemsViewCell2)
+				{
+					return true;
+				}
+				superview = superview.Superview;
+			}
+			return false;
+		}
 	}
 }