Stepper doesn't change increment value when being bound to a double in MVVM context (Windows)

src/Controls/src/Core/Stepper/Stepper.Android.cs

@@ -0,0 +1,11 @@
+using System;
+
+namespace Microsoft.Maui.Controls;
+
+public class Stepper.Android
+{
+    internal static void MapInterval(IStepperHandler handler, IStepper view)
+    {
+       handler.PlatformView.UpdateIncrement(view);
+    }
+}

src/Controls/src/Core/Stepper/Stepper.Mapper.cs

@@ -0,0 +1,10 @@
+using System;
+
+namespace Microsoft.Maui.Controls;
+public partial class Stepper
+{
+    internal static new void RemapForControls()
+    {
+        StepperHandler.Mapper.AppendToMapping(nameof(Stepper.Increment), Stepper.MapInterval);
+    }
+}

src/Controls/src/Core/Stepper/Stepper.Standard.cs

@@ -0,0 +1,8 @@
+using System;
+
+namespace Microsoft.Maui.Controls;
+
+public partial class Stepper
+{
+    internal static void MapInterval(IStepperHandler handler, IStepper view){}
+}

src/Controls/src/Core/Stepper/Stepper.Tizen.cs

@@ -0,0 +1,11 @@
+using System;
+
+namespace Microsoft.Maui.Controls;
+
+public partial class Stepper
+{
+    internal static void MapInterval(IStepperHandler handler, IStepper view)
+    {
+        handler.PlatformView.UpdateIncrement(view);
+    }
+}

src/Controls/src/Core/Stepper/Stepper.Windows.cs

@@ -0,0 +1,11 @@
+using System;
+
+namespace Microsoft.Maui.Controls;
+
+public partial class Stepper
+{
+    internal static void MapInterval(IStepperHandler handler, IStepper view)
+    {
+       handler.PlatformView.UpdateInterval(view);
+    }
+}

src/Controls/src/Core/Stepper/Stepper.cs

@@ -45,7 +45,7 @@ public partial class Stepper : View, IElementConfiguration<Stepper>, IStepper
 		//'-log10(increment) + 4' as rounding digits gives us 4 significant decimal digits after the most significant one.
 		//If your increment uses more than 4 significant digits, you're holding it wrong.
 		/// <summary>Bindable property for <see cref="Increment"/>.</summary>
-		public static readonly BindableProperty IncrementProperty = BindableProperty.Create(nameof(Increment), typeof(double), typeof(Stepper), 1.0,
+			public static readonly BindableProperty IncrementProperty = BindableProperty.Create(nameof(Increment), typeof(double), typeof(Stepper), 1.0,
 			propertyChanged: (b, o, n) => { ((Stepper)b).digits = (int)(-Math.Log10((double)n) + 4).Clamp(1, 15); });
 
 		readonly Lazy<PlatformConfigurationRegistry<Stepper>> _platformConfigurationRegistry;

src/Controls/src/Core/Stepper/Stepper.iOS.cs

@@ -0,0 +1,11 @@
+using System;
+
+namespace Microsoft.Maui.Controls;
+
+public class Stepper.iOS
+{
+    internal static void MapInterval(IStepperHandler handler, IStepper view)
+    {
+       handler.PlatformView.UpdateIncrement(view);
+    }
+}

src/Controls/tests/TestCases.HostApp/Issues/Issue20706.xaml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="Maui.Controls.Sample.Issues.Issue20706"
+             xmlns:local="clr-namespace:Maui.Controls.Sample.Issues">
+  <ContentPage.BindingContext>
+    <local:ViewModelClass/>
+  </ContentPage.BindingContext>
+  <ContentPage.Content>
+    <VerticalStackLayout>
+      <Stepper AutomationId="myStepper" x:Name="stepperValue"
+               Maximum="1000"
+	            Increment="{Binding Increment}" />
+      <Entry AutomationId="entry" 
+	          Text="{Binding Value,Source={x:Reference stepperValue}} "/>
+      <Button AutomationId="incrementButton" Text="Change Increment Value" x:Name="button" Clicked="button_Clicked"/>
+    </VerticalStackLayout>
+  </ContentPage.Content>
+</ContentPage>

src/Controls/tests/TestCases.HostApp/Issues/Issue20706.xaml.cs

@@ -0,0 +1,51 @@
+using System.ComponentModel;
+
+namespace Maui.Controls.Sample.Issues
+{
+	[Issue(IssueTracker.Github, 20706, "Stepper doesn't change increment value when being bound to a double in MVVM context (Windows)", PlatformAffected.UWP)]
+	public partial class Issue20706 : ContentPage
+	{
+		public Issue20706 ()
+		{
+			InitializeComponent ();
+		}
+
+		private void button_Clicked(object sender, EventArgs e)
+		{
+			stepperValue.Increment = 10;
+		}
+    }
+
+	internal class ViewModelClass : INotifyPropertyChanged
+	{
+		private double _increment;
+
+		public double Increment
+		{
+			get
+			{
+				return _increment;
+			}
+
+			set
+			{
+				_increment = value;
+				OnPropertyChanged("Increment");
+			}
+		}
+
+		public ViewModelClass()
+		{
+			Increment = 2;
+		}
+		private void OnPropertyChanged(string v)
+		{
+			if (PropertyChanged != null)
+			{
+				PropertyChanged(this, new PropertyChangedEventArgs(v));
+			}
+		}
+
+		public event PropertyChangedEventHandler PropertyChanged;
+	}
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue20706.cs

@@ -0,0 +1,28 @@
+#if !MACCATALYST
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+    public class Issue20706 : _IssuesUITest
+	{
+		public override string Issue => "Stepper doesn't change increment value when being bound to a double in MVVM context (Windows)";
+		public Issue20706(TestDevice device) : base(device)
+		{
+		}
+
+		[Test]
+		[Category(UITestCategories.Stepper)]
+		public void ChangeIncrementValue()
+		{
+			App.WaitForElement("incrementButton");
+			App.IncreaseStepper("myStepper");
+			App.Click("incrementButton");
+			App.IncreaseStepper("myStepper");
+			App.DecreaseStepper("myStepper");
+			VerifyScreenshot();
+		}
+	}
+}
+#endif