[WinUI] Perf when creating non-trivial grids (and other visual controls)

src/Controls/samples/Controls.Sample.Sandbox/MainPage.xaml

@@ -1,6 +1,18 @@
 <ContentPage
     xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
     xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+    xmlns:local="clr-namespace:Maui.Controls.Sample"
     x:Class="Maui.Controls.Sample.MainPage"
-    xmlns:local="clr-namespace:Maui.Controls.Sample">
+    x:DataType="local:MainPage">
+    <VerticalStackLayout x:Name="myLayout">
+        <Label x:Name="info" Text="Click a button" VerticalOptions="Center"/>
+        <Button Text="Clear Grid" Clicked="ClearGrid_Clicked"/>
+        <Button Text="Generate Grid" Clicked="Button_Clicked"/>
+        <Entry x:Name="BatchSize" Text="15"/>
+        <Button Text="Batch Generate Grid" Clicked="BatchGenerate_Clicked"/>
+
+        <HorizontalStackLayout x:Name="myGridWrapper">
+            <Grid x:Name="contentGrid"/>
+        </HorizontalStackLayout>
+    </VerticalStackLayout>
 </ContentPage>

src/Controls/samples/Controls.Sample.Sandbox/MainPage.xaml.cs

@@ -1,18 +1,70 @@
 using System;
-using System.Collections.ObjectModel;
 using System.Diagnostics;
-using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Maui;
 using Microsoft.Maui.Controls;
-using Microsoft.Maui.Graphics;
 
-namespace Maui.Controls.Sample
+namespace Maui.Controls.Sample;
+
+public partial class MainPage : ContentPage
 {
-	public partial class MainPage : ContentPage
+	const int rowCount = 30;
+	const int columnCount = 30;
+
+	public MainPage()
+	{
+		InitializeComponent();
+	}
+
+	private void ClearGrid_Clicked(object sender, EventArgs e)
+	{
+		Stopwatch sw = Stopwatch.StartNew();
+
+		contentGrid.Clear();
+
+		sw.Stop();
+
+		info.Text = $"Clearing grid took: {sw.ElapsedMilliseconds} ms";
+	}
+
+	private void Button_Clicked(object sender, EventArgs e)
 	{
-		public MainPage()
+		Stopwatch sw = Stopwatch.StartNew();
+		contentGrid.Clear();
+
+		for (int rowIndex = 0; rowIndex < rowCount; rowIndex++)
 		{
-			InitializeComponent();
+			for (int columnIndex = 0; columnIndex < columnCount; columnIndex++)
+			{
+				Label label = new Label() { Text = $"[{columnIndex}x{rowIndex}]" };
+				contentGrid.Add(label, column: columnIndex, row: rowIndex);
+			}
 		}
+
+		sw.Stop();
+		info.Text = $"Clearing grid took: {sw.ElapsedMilliseconds} ms";
 	}
+
+	private void BatchGenerate_Clicked(object sender, EventArgs e)
+	{
+		Stopwatch sw = Stopwatch.StartNew();		
+
+		int batchSize = int.Parse(BatchSize.Text);
+
+		for (int i = 0; i < batchSize; i++)
+		{
+			contentGrid.Clear();
+
+			for (int rowIndex = 0; rowIndex < rowCount; rowIndex++)
+			{
+				for (int columnIndex = 0; columnIndex < columnCount; columnIndex++)
+				{
+					Label label = new Label() { Text = $"[{columnIndex}x{rowIndex}]" };
+					contentGrid.Add(label, column: columnIndex, row: rowIndex);
+				}
+			}
+		}
+
+		sw.Stop();
+		info.Text = $"Grid was created {batchSize} times and it took {sw.ElapsedMilliseconds} ms in total. Avg run took {Math.Round(sw.ElapsedMilliseconds / (double)batchSize, 2)} ms";
+	}
+
 }

src/Core/src/Handlers/View/ViewHandler.cs

@@ -27,6 +27,9 @@ public abstract partial class ViewHandler : ElementHandler, IViewHandler
 #if ANDROID
 			// Use a custom mapper for Android which knows how to batch the initial property sets
 			new AndroidBatchPropertyMapper<IView, IViewHandler>(ElementMapper)
+#elif WINDOWS
+			// Use a custom mapper for Windows which knows how to batch the initial property sets
+			new WindowsBatchPropertyMapper<IView, IViewHandler>(ElementMapper)
 #else
 			new PropertyMapper<IView, IViewHandler>(ElementHandler.ElementMapper)
 #endif

src/Core/src/Handlers/View/WindowsBatchPropertyMapper.cs

@@ -0,0 +1,50 @@
+using System;
+using System.Collections.Generic;
+
+namespace Microsoft.Maui.Handlers;
+
+#if WINDOWS
+class WindowsBatchPropertyMapper<TVirtualView, TViewHandler> : PropertyMapper<TVirtualView, TViewHandler>
+	where TVirtualView : IElement
+	where TViewHandler : IElementHandler
+{
+	// During mass property updates, this list of properties will be skipped
+	public static HashSet<string> SkipList = new(StringComparer.Ordinal)
+	{ 
+		// TranslationX does the work that is necessary to make other properties work.
+		nameof(IView.TranslationY),
+		nameof(IView.Scale),
+		nameof(IView.ScaleX),
+		nameof(IView.ScaleY),
+		nameof(IView.Rotation),
+		nameof(IView.RotationX),
+		nameof(IView.RotationY),
+		nameof(IView.AnchorX),
+		nameof(IView.AnchorY),
+	};
+
+	public WindowsBatchPropertyMapper(params IPropertyMapper[] chained) : base(chained) { }
+
+	public override IEnumerable<string> GetKeys()
+	{
+		foreach (var key in _mapper.Keys)
+		{
+			// When reporting the key list for mass updates up the chain, ignore properties in SkipList.
+			// These will be handled by ViewHandler.SetVirtualView() instead.
+			if (SkipList.Contains(key))
+			{
+				continue;
+			}
+
+			yield return key;
+		}
+
+		if (Chained is not null)
+		{
+			foreach (var chain in Chained)
+				foreach (var key in chain.GetKeys())
+					yield return key;
+		}
+	}
+}
+#endif