Implement Progress proprerty in WinUI ProgressBarHandler

src/Core/src/Handlers/ProgressBar/ProgressBarHandler.Windows.cs

@@ -1,13 +1,14 @@
-using System;
-using Microsoft.UI.Xaml.Controls;
+using Microsoft.UI.Xaml.Controls;
 
 namespace Microsoft.Maui.Handlers
 {
 	public partial class ProgressBarHandler : ViewHandler<IProgress, ProgressBar>
 	{
-		protected override ProgressBar CreateNativeView() => new ProgressBar();
+		protected override ProgressBar CreateNativeView() => new ProgressBar { Minimum = 0, Maximum = 1 };
 
-		[MissingMapper]
-		public static void MapProgress(ProgressBarHandler handler, IProgress progress) { }
+		public static void MapProgress(ProgressBarHandler handler, IProgress progress)	
+		{
+			handler.NativeView?.UpdateProgress(progress);
+		}
 	}
 }

src/Core/src/Platform/Windows/ProgressBarExtensions.cs

@@ -0,0 +1,12 @@
+using Microsoft.UI.Xaml.Controls;
+
+namespace Microsoft.Maui
+{
+	public static class ProgressBarExtensions
+	{
+		public static void UpdateProgress(this ProgressBar nativeProgressBar, IProgress progress)
+		{
+			nativeProgressBar.Value = progress.Progress;
+		}
+	}
+}